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conditionally add wordexp, in this case ripped from glibc.
authorEric Andersen <andersen@codepoet.org>
Sun, 24 Aug 2003 05:11:50 +0000 (05:11 -0000)
committerEric Andersen <andersen@codepoet.org>
Sun, 24 Aug 2003 05:11:50 +0000 (05:11 -0000)
I hate to add this stuff, but it is specified by SuSv3...

libc/misc/Makefile
libc/misc/wordexp/Makefile [new file with mode: 0644]
libc/misc/wordexp/wordexp.c [new file with mode: 0644]

index 037e215..24a9635 100644 (file)
@@ -27,10 +27,13 @@ include $(TOPDIR)Rules.mak
 
 DIRS = assert ctype dirent file fnmatch glob internals \
        mntent syslog time utmp sysvipc statfs \
-       error ttyent gnu search intl locale 
+       error ttyent gnu search intl locale
 ifeq ($(strip $(UCLIBC_HAS_REGEX)),y)
 DIRS += regex
 endif
+ifeq ($(strip $(UCLIBC_HAS_WORDEXP)),y)
+DIRS += wordexp
+endif
 ifeq ($(strip $(UCLIBC_HAS_THREADS)),y)
 DIRS += pthread
 endif
diff --git a/libc/misc/wordexp/Makefile b/libc/misc/wordexp/Makefile
new file mode 100644 (file)
index 0000000..edfd819
--- /dev/null
@@ -0,0 +1,39 @@
+# Makefile for uClibc
+#
+# Copyright (C) 2003 Erik Andersen <andersen@uclibc.org>
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Library General Public License as published by the Free
+# Software Foundation; either version 2 of the License, or (at your option) any
+# later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Library General Public License
+# along with this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+TOPDIR=../../../
+include $(TOPDIR)Rules.mak
+
+CSRC=wordexp.c
+COBJS=$(patsubst %.c,%.o, $(CSRC))
+OBJS=$(COBJS)
+
+all: $(OBJS) $(LIBC)
+
+$(LIBC): ar-target
+
+ar-target: $(OBJS)
+       $(AR) $(ARFLAGS) $(LIBC) $(OBJS)
+
+$(COBJS): %.o : %.c
+       $(CC) $(CFLAGS) -c $< -o $@
+       $(STRIPTOOL) -x -R .note -R .comment $*.o
+
+clean:
+       rm -f *.[oa] *~ core
+
diff --git a/libc/misc/wordexp/wordexp.c b/libc/misc/wordexp/wordexp.c
new file mode 100644 (file)
index 0000000..628b8f3
--- /dev/null
@@ -0,0 +1,2244 @@
+/* vi: set sw=4 ts=4: */
+/* POSIX.2 wordexp implementation.
+   Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Tim Waugh <tim@cyberelk.demon.co.uk>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#define _GNU_SOURCE
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <errno.h>
+#include <assert.h>
+#include <fnmatch.h>
+#include <glob.h>
+#include <wordexp.h>
+
+#define __WORDEXP_FULL
+//#undef __WORDEXP_FULL
+
+/*
+ * This is a recursive-descent-style word expansion routine.
+ */
+
+/* These variables are defined and initialized in the startup code.  */
+//extern int __libc_argc;
+//extern char **__libc_argv;
+
+/* FIXME!!!! */
+int __libc_argc;
+char **__libc_argv;
+
+/* Some forward declarations */
+static int parse_dollars(char **word, size_t * word_length,
+                                                size_t * max_length, const char *words,
+                                                size_t * offset, int flags, wordexp_t * pwordexp,
+                                                const char *ifs, const char *ifs_white,
+                                                int quoted);
+static int parse_backtick(char **word, size_t * word_length,
+                                                 size_t * max_length, const char *words,
+                                                 size_t * offset, int flags, wordexp_t * pwordexp,
+                                                 const char *ifs, const char *ifs_white);
+static int parse_dquote(char **word, size_t * word_length,
+                                               size_t * max_length, const char *words,
+                                               size_t * offset, int flags, wordexp_t * pwordexp,
+                                               const char *ifs, const char *ifs_white);
+
+
+
+/* The w_*() functions manipulate word lists. */
+#define W_CHUNK        (100)
+
+/* Result of w_newword will be ignored if it's the last word. */
+static inline char *w_newword(size_t * actlen, size_t * maxlen)
+{
+       *actlen = *maxlen = 0;
+       return NULL;
+}
+
+/* Add a character to the buffer, allocating room for it if needed.  */
+static inline char *w_addchar(char *buffer, size_t * actlen,
+                                                         size_t * maxlen, char ch)
+        /* (lengths exclude trailing zero) */
+{
+
+       if (*actlen == *maxlen) {
+               char *old_buffer = buffer;
+               assert(buffer == NULL || *maxlen != 0);
+               *maxlen += W_CHUNK;
+               buffer = realloc(buffer, 1 + *maxlen);
+               if (buffer == NULL)
+                       free(old_buffer);
+       }
+
+       if (buffer != NULL) {
+               buffer[*actlen] = ch;
+               buffer[++(*actlen)] = '\0';
+       }
+
+       return buffer;
+}
+
+#define MAX( a, b ) ( ( ( a ) > ( b ) ) ? ( a ) : ( b ) )
+static char *w_addmem(char *buffer, size_t * actlen, size_t * maxlen,
+                                         const char *str, size_t len)
+{
+       /* Add a string to the buffer, allocating room for it if needed.
+        */
+       if (*actlen + len > *maxlen) {
+               char *old_buffer = buffer;
+               assert(buffer == NULL || *maxlen != 0);
+               *maxlen += MAX(2 * len, W_CHUNK);
+               buffer = realloc(old_buffer, 1 + *maxlen);
+               if (buffer == NULL)
+                       free(old_buffer);
+       }
+
+       if (buffer != NULL) {
+               *((char *) mempcpy(&buffer[*actlen], str, len)) = '\0';
+               *actlen += len;
+       }
+       return buffer;
+}
+
+/* Add a string to the buffer, allocating room for it if needed.  */
+static char *w_addstr(char *buffer, size_t * actlen, size_t * maxlen,
+                                         const char *str)
+        /* (lengths exclude trailing zero) */
+{
+       size_t len;
+       assert(str != NULL);            /* w_addstr only called from this file */
+       len = strlen(str);
+
+       return w_addmem(buffer, actlen, maxlen, str, len);
+}
+
+/* Add a word to the wordlist */
+static int w_addword(wordexp_t * pwordexp, char *word)
+{
+       size_t num_p;
+       char **new_wordv;
+
+       /* Internally, NULL acts like "".  Convert NULLs to "" before
+        * the caller sees them.
+        */
+       if (word == NULL) {
+               word = strdup("");
+               if (word == NULL)
+                       goto no_space;
+       }
+
+       num_p = 2 + pwordexp->we_wordc + pwordexp->we_offs;
+       new_wordv = realloc(pwordexp->we_wordv, sizeof(char *) * num_p);
+       if (new_wordv != NULL) {
+               pwordexp->we_wordv = new_wordv;
+               pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc++] = word;
+               pwordexp->we_wordv[pwordexp->we_offs + pwordexp->we_wordc] = NULL;
+               return 0;
+       }
+
+  no_space:
+       return WRDE_NOSPACE;
+}
+
+/* The parse_*() functions should leave *offset being the offset in 'words'
+ * to the last character processed.
+ */
+static int
+parse_backslash(char **word, size_t * word_length, size_t * max_length,
+                               const char *words, size_t * offset)
+{
+       /* We are poised _at_ a backslash, not in quotes */
+
+       switch (words[1 + *offset]) {
+       case 0:
+               /* Backslash is last character of input words */
+               return WRDE_SYNTAX;
+
+       case '\n':
+               ++(*offset);
+               break;
+
+       default:
+               *word = w_addchar(*word, word_length, max_length, words[1 + *offset]);
+               if (*word == NULL)
+                       return WRDE_NOSPACE;
+
+               ++(*offset);
+               break;
+       }
+
+       return 0;
+}
+
+static int
+parse_qtd_backslash(char **word, size_t * word_length, size_t * max_length,
+                                       const char *words, size_t * offset)
+{
+       /* We are poised _at_ a backslash, inside quotes */
+
+       switch (words[1 + *offset]) {
+       case 0:
+               /* Backslash is last character of input words */
+               return WRDE_SYNTAX;
+
+       case '\n':
+               ++(*offset);
+               break;
+
+       case '$':
+       case '`':
+       case '"':
+       case '\\':
+               *word =
+                       w_addchar(*word, word_length, max_length, words[1 + *offset]);
+               if (*word == NULL)
+                       return WRDE_NOSPACE;
+
+               ++(*offset);
+               break;
+
+       default:
+               *word = w_addchar(*word, word_length, max_length, words[*offset]);
+               if (*word != NULL)
+                       *word =
+                               w_addchar(*word, word_length, max_length,
+                                                 words[1 + *offset]);
+
+               if (*word == NULL)
+                       return WRDE_NOSPACE;
+
+               ++(*offset);
+               break;
+       }
+
+       return 0;
+}
+
+static int
+parse_tilde(char **word, size_t * word_length, size_t * max_length,
+                       const char *words, size_t * offset, size_t wordc)
+{
+       /* We are poised _at_ a tilde */
+       size_t i;
+
+       if (*word_length != 0) {
+               if (!((*word)[*word_length - 1] == '=' && wordc == 0)) {
+                       if (!((*word)[*word_length - 1] == ':'
+                                 && strchr(*word, '=') && wordc == 0)) {
+                               *word = w_addchar(*word, word_length, max_length, '~');
+                               return *word ? 0 : WRDE_NOSPACE;
+                       }
+               }
+       }
+
+       for (i = 1 + *offset; words[i]; i++) {
+               if (words[i] == ':' || words[i] == '/' || words[i] == ' ' ||
+                       words[i] == '\t' || words[i] == 0)
+                       break;
+
+               if (words[i] == '\\') {
+                       *word = w_addchar(*word, word_length, max_length, '~');
+                       return *word ? 0 : WRDE_NOSPACE;
+               }
+       }
+
+       if (i == 1 + *offset) {
+               /* Tilde appears on its own */
+               uid_t uid;
+               struct passwd pwd, *tpwd;
+               int buflen = 1000;
+               char *home;
+               char *buffer;
+               int result;
+
+               /* POSIX.2 says ~ expands to $HOME and if HOME is unset the
+                  results are unspecified.  We do a lookup on the uid if
+                  HOME is unset. */
+
+               home = getenv("HOME");
+               if (home != NULL) {
+                       *word = w_addstr(*word, word_length, max_length, home);
+                       if (*word == NULL)
+                               return WRDE_NOSPACE;
+               } else {
+                       uid = getuid();
+                       buffer = alloca(buflen);
+
+                       while ((result = getpwuid_r(uid, &pwd, buffer, buflen, &tpwd)) 
+                                       != 0 && errno == ERANGE) 
+                       {
+                               buflen += 1000;
+                               buffer = alloca(buflen);
+                       }
+
+                       if (result == 0 && tpwd != NULL && pwd.pw_dir != NULL) {
+                               *word = w_addstr(*word, word_length, max_length, pwd.pw_dir);
+                               if (*word == NULL)
+                                       return WRDE_NOSPACE;
+                       } else {
+                               *word = w_addchar(*word, word_length, max_length, '~');
+                               if (*word == NULL)
+                                       return WRDE_NOSPACE;
+                       }
+               }
+       } else {
+               /* Look up user name in database to get home directory */
+               char *user = strndup(&words[1 + *offset], i - (1 + *offset));
+               struct passwd pwd, *tpwd;
+               int buflen = 1000;
+               char *buffer = alloca(buflen);
+               int result;
+
+               while ((result = getpwnam_r(user, &pwd, buffer, buflen, &tpwd)) != 0
+                          && errno == ERANGE) {
+                       buflen += 1000;
+                       buffer = alloca(buflen);
+               }
+
+               if (result == 0 && tpwd != NULL && pwd.pw_dir)
+                       *word = w_addstr(*word, word_length, max_length, pwd.pw_dir);
+               else {
+                       /* (invalid login name) */
+                       *word = w_addchar(*word, word_length, max_length, '~');
+                       if (*word != NULL)
+                               *word = w_addstr(*word, word_length, max_length, user);
+               }
+
+               *offset = i - 1;
+       }
+       return *word ? 0 : WRDE_NOSPACE;
+}
+
+
+static int
+do_parse_glob(const char *glob_word, char **word, size_t * word_length,
+                         size_t * max_length, wordexp_t * pwordexp, const char *ifs,
+                         const char *ifs_white)
+{
+       int error;
+       int match;
+       glob_t globbuf;
+
+       error = glob(glob_word, GLOB_NOCHECK, NULL, &globbuf);
+
+       if (error != 0) {
+               /* We can only run into memory problems.  */
+               assert(error == GLOB_NOSPACE);
+               return WRDE_NOSPACE;
+       }
+
+       if (ifs && !*ifs) {
+               /* No field splitting allowed. */
+               assert(globbuf.gl_pathv[0] != NULL);
+               *word = w_addstr(*word, word_length, max_length, globbuf.gl_pathv[0]);
+               for (match = 1; match < globbuf.gl_pathc && *word != NULL; ++match) {
+                       *word = w_addchar(*word, word_length, max_length, ' ');
+                       if (*word != NULL)
+                               *word = w_addstr(*word, word_length, max_length,
+                                                                globbuf.gl_pathv[match]);
+               }
+
+               globfree(&globbuf);
+               return *word ? 0 : WRDE_NOSPACE;
+       }
+
+       assert(ifs == NULL || *ifs != '\0');
+       if (*word != NULL) {
+               free(*word);
+               *word = w_newword(word_length, max_length);
+       }
+
+       for (match = 0; match < globbuf.gl_pathc; ++match) {
+               char *matching_word = strdup(globbuf.gl_pathv[match]);
+
+               if (matching_word == NULL || w_addword(pwordexp, matching_word)) {
+                       globfree(&globbuf);
+                       return WRDE_NOSPACE;
+               }
+       }
+
+       globfree(&globbuf);
+       return 0;
+}
+
+static int
+parse_glob(char **word, size_t * word_length, size_t * max_length,
+                  const char *words, size_t * offset, int flags,
+                  wordexp_t * pwordexp, const char *ifs, const char *ifs_white)
+{
+       /* We are poised just after a '*', a '[' or a '?'. */
+       int error = WRDE_NOSPACE;
+       int quoted = 0;                         /* 1 if singly-quoted, 2 if doubly */
+       int i;
+       wordexp_t glob_list;            /* List of words to glob */
+
+       glob_list.we_wordc = 0;
+       glob_list.we_wordv = NULL;
+       glob_list.we_offs = 0;
+       for (; words[*offset] != '\0'; ++*offset) {
+               if ((ifs && strchr(ifs, words[*offset])) ||
+                       (!ifs && strchr(" \t\n", words[*offset])))
+                       /* Reached IFS */
+                       break;
+
+               /* Sort out quoting */
+               if (words[*offset] == '\'') {
+                       if (quoted == 0) {
+                               quoted = 1;
+                               continue;
+                       } else if (quoted == 1) {
+                               quoted = 0;
+                               continue;
+                       }
+               } else if (words[*offset] == '"') {
+                       if (quoted == 0) {
+                               quoted = 2;
+                               continue;
+                       } else if (quoted == 2) {
+                               quoted = 0;
+                               continue;
+                       }
+               }
+
+               /* Sort out other special characters */
+               if (quoted != 1 && words[*offset] == '$') {
+                       error = parse_dollars(word, word_length, max_length, words,
+                                                                 offset, flags, &glob_list, ifs,
+                                                                 ifs_white, quoted == 2);
+                       if (error)
+                               goto tidy_up;
+
+                       continue;
+               } else if (words[*offset] == '\\') {
+                       if (quoted)
+                               error = parse_qtd_backslash(word, word_length, max_length,
+                                                                                       words, offset);
+                       else
+                               error = parse_backslash(word, word_length, max_length,
+                                                                               words, offset);
+
+                       if (error)
+                               goto tidy_up;
+
+                       continue;
+               }
+
+               *word = w_addchar(*word, word_length, max_length, words[*offset]);
+               if (*word == NULL)
+                       goto tidy_up;
+       }
+
+       /* Don't forget to re-parse the character we stopped at. */
+       --*offset;
+
+       /* Glob the words */
+       error = w_addword(&glob_list, *word);
+       *word = w_newword(word_length, max_length);
+       for (i = 0; error == 0 && i < glob_list.we_wordc; i++)
+               error = do_parse_glob(glob_list.we_wordv[i], word, word_length,
+                                                         max_length, pwordexp, ifs, ifs_white);
+
+       /* Now tidy up */
+  tidy_up:
+       wordfree(&glob_list);
+       return error;
+}
+
+static int
+parse_squote(char **word, size_t * word_length, size_t * max_length,
+                        const char *words, size_t * offset)
+{
+       /* We are poised just after a single quote */
+       for (; words[*offset]; ++(*offset)) {
+               if (words[*offset] != '\'') {
+                       *word = w_addchar(*word, word_length, max_length, words[*offset]);
+                       if (*word == NULL)
+                               return WRDE_NOSPACE;
+               } else
+                       return 0;
+       }
+
+       /* Unterminated string */
+       return WRDE_SYNTAX;
+}
+
+#ifdef __WORDEXP_FULL
+static int eval_expr(char *expr, long int *result);
+
+static char *_itoa(unsigned long long int value, char *buflim)
+{
+       sprintf(buflim, "%llu", value);
+       return buflim;
+}
+
+/* Functions to evaluate an arithmetic expression */
+static int eval_expr_val(char **expr, long int *result)
+{
+       int sgn = +1;
+       char *digit;
+
+       /* Skip white space */
+       for (digit = *expr; digit && *digit && isspace(*digit); ++digit);
+
+       switch (*digit) {
+       case '(':
+
+               /* Scan for closing paren */
+               for (++digit; **expr && **expr != ')'; ++(*expr));
+
+               /* Is there one? */
+               if (!**expr)
+                       return WRDE_SYNTAX;
+
+               *(*expr)++ = 0;
+
+               if (eval_expr(digit, result))
+                       return WRDE_SYNTAX;
+
+               return 0;
+
+       case '+':                                       /* Positive value */
+               ++digit;
+               break;
+
+       case '-':                                       /* Negative value */
+               ++digit;
+               sgn = -1;
+               break;
+
+       default:
+               if (!isdigit(*digit))
+                       return WRDE_SYNTAX;
+       }
+
+       *result = 0;
+       for (; *digit && isdigit(*digit); ++digit)
+               *result = (*result * 10) + (*digit - '0');
+
+       *expr = digit;
+       *result *= sgn;
+       return 0;
+}
+
+static int eval_expr_multdiv(char **expr, long int *result)
+{
+       long int arg;
+
+       /* Read a Value */
+       if (eval_expr_val(expr, result) != 0)
+               return WRDE_SYNTAX;
+
+       while (**expr) {
+               /* Skip white space */
+               for (; *expr && **expr && isspace(**expr); ++(*expr));
+
+               if (**expr == '*') {
+                       ++(*expr);
+                       if (eval_expr_val(expr, &arg) != 0)
+                               return WRDE_SYNTAX;
+
+                       *result *= arg;
+               } else if (**expr == '/') {
+                       ++(*expr);
+                       if (eval_expr_val(expr, &arg) != 0)
+                               return WRDE_SYNTAX;
+
+                       *result /= arg;
+               } else
+                       break;
+       }
+
+       return 0;
+}
+
+static int eval_expr(char *expr, long int *result)
+{
+       long int arg;
+
+       /* Read a Multdiv */
+       if (eval_expr_multdiv(&expr, result) != 0)
+               return WRDE_SYNTAX;
+
+       while (*expr) {
+               /* Skip white space */
+               for (; expr && *expr && isspace(*expr); ++expr);
+
+               if (*expr == '+') {
+                       ++expr;
+                       if (eval_expr_multdiv(&expr, &arg) != 0)
+                               return WRDE_SYNTAX;
+
+                       *result += arg;
+               } else if (*expr == '-') {
+                       ++expr;
+                       if (eval_expr_multdiv(&expr, &arg) != 0)
+                               return WRDE_SYNTAX;
+
+                       *result -= arg;
+               } else
+                       break;
+       }
+
+       return 0;
+}
+
+static int
+parse_arith(char **word, size_t * word_length, size_t * max_length,
+                       const char *words, size_t * offset, int flags, int bracket)
+{
+       /* We are poised just after "$((" or "$[" */
+       int error;
+       int paren_depth = 1;
+       size_t expr_length;
+       size_t expr_maxlen;
+       char *expr;
+
+       expr = w_newword(&expr_length, &expr_maxlen);
+       for (; words[*offset]; ++(*offset)) {
+               switch (words[*offset]) {
+               case '$':
+                       error = parse_dollars(&expr, &expr_length, &expr_maxlen,
+                                                                 words, offset, flags, NULL, NULL, NULL,
+                                                                 1);
+                       /* The ``1'' here is to tell parse_dollars not to
+                        * split the fields.
+                        */
+                       if (error) {
+                               free(expr);
+                               return error;
+                       }
+                       break;
+
+               case '`':
+                       (*offset)++;
+                       error = parse_backtick(&expr, &expr_length, &expr_maxlen,
+                                                                  words, offset, flags, NULL, NULL, NULL);
+                       /* The first NULL here is to tell parse_backtick not to
+                        * split the fields.
+                        */
+                       if (error) {
+                               free(expr);
+                               return error;
+                       }
+                       break;
+
+               case '\\':
+                       error = parse_qtd_backslash(&expr, &expr_length, &expr_maxlen,
+                                                                               words, offset);
+                       if (error) {
+                               free(expr);
+                               return error;
+                       }
+                       /* I think that a backslash within an
+                        * arithmetic expansion is bound to
+                        * cause an error sooner or later anyway though.
+                        */
+                       break;
+
+               case ')':
+                       if (--paren_depth == 0) {
+                               char result[21];        /* 21 = ceil(log10(2^64)) + 1 */
+                               long int numresult = 0;
+                               long long int convertme;
+
+                               if (bracket || words[1 + *offset] != ')') {
+                                       free(expr);
+                                       return WRDE_SYNTAX;
+                               }
+
+                               ++(*offset);
+
+                               /* Go - evaluate. */
+                               if (*expr && eval_expr(expr, &numresult) != 0) {
+                                       free(expr);
+                                       return WRDE_SYNTAX;
+                               }
+
+                               if (numresult < 0) {
+                                       convertme = -numresult;
+                                       *word = w_addchar(*word, word_length, max_length, '-');
+                                       if (!*word) {
+                                               free(expr);
+                                               return WRDE_NOSPACE;
+                                       }
+                               } else
+                                       convertme = numresult;
+
+                               result[20] = '\0';
+                               *word = w_addstr(*word, word_length, max_length,
+                                                                _itoa(convertme, &result[20]));
+                               free(expr);
+                               return *word ? 0 : WRDE_NOSPACE;
+                       }
+                       expr =
+                               w_addchar(expr, &expr_length, &expr_maxlen,
+                                                 words[*offset]);
+                       if (expr == NULL)
+                               return WRDE_NOSPACE;
+
+                       break;
+
+               case ']':
+                       if (bracket && paren_depth == 1) {
+                               char result[21];        /* 21 = ceil(log10(2^64)) + 1 */
+                               long int numresult = 0;
+
+                               /* Go - evaluate. */
+                               if (*expr && eval_expr(expr, &numresult) != 0) {
+                                       free(expr);
+                                       return WRDE_SYNTAX;
+                               }
+
+                               result[20] = '\0';
+                               *word = w_addstr(*word, word_length, max_length,
+                                                                _itoa(numresult, &result[20]));
+                               free(expr);
+                               return *word ? 0 : WRDE_NOSPACE;
+                       }
+
+                       free(expr);
+                       return WRDE_SYNTAX;
+
+               case '\n':
+               case ';':
+               case '{':
+               case '}':
+                       free(expr);
+                       return WRDE_BADCHAR;
+
+               case '(':
+                       ++paren_depth;
+               default:
+                       expr =
+                               w_addchar(expr, &expr_length, &expr_maxlen,
+                                                 words[*offset]);
+                       if (expr == NULL)
+                               return WRDE_NOSPACE;
+               }
+       }
+
+       /* Premature end */
+       free(expr);
+       return WRDE_SYNTAX;
+}
+
+/* Function called by child process in exec_comm() */
+static void
+exec_comm_child(char *comm, int *fildes, int showerr, int noexec)
+{
+       const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL };
+
+       /* Execute the command, or just check syntax? */
+       if (noexec)
+               args[1] = "-nc";
+
+       /* Redirect output.  */
+       dup2(fildes[1], 1);
+       close(fildes[1]);
+
+       /* Redirect stderr to /dev/null if we have to.  */
+       if (showerr == 0) {
+               int fd;
+
+               close(2);
+               fd = open(_PATH_DEVNULL, O_WRONLY);
+               if (fd >= 0 && fd != 2) {
+                       dup2(fd, 2);
+                       close(fd);
+               }
+       }
+
+       /* Make sure the subshell doesn't field-split on our behalf. */
+       unsetenv("IFS");
+
+       close(fildes[0]);
+       execve(_PATH_BSHELL, (char *const *) args, __environ);
+
+       /* Bad.  What now?  */
+       abort();
+}
+
+/* Function to execute a command and retrieve the results */
+/* pwordexp contains NULL if field-splitting is forbidden */
+static int
+exec_comm(char *comm, char **word, size_t * word_length,
+                 size_t * max_length, int flags, wordexp_t * pwordexp,
+                 const char *ifs, const char *ifs_white)
+{
+       int fildes[2];
+       int bufsize = 128;
+       int buflen;
+       int i;
+       int status = 0;
+       size_t maxnewlines = 0;
+       char *buffer;
+       pid_t pid;
+
+       /* Don't fork() unless necessary */
+       if (!comm || !*comm)
+               return 0;
+
+       if (pipe(fildes))
+               /* Bad */
+               return WRDE_NOSPACE;
+
+       if ((pid = fork()) < 0) {
+               /* Bad */
+               close(fildes[0]);
+               close(fildes[1]);
+               return WRDE_NOSPACE;
+       }
+
+       if (pid == 0)
+               exec_comm_child(comm, fildes, (flags & WRDE_SHOWERR), 0);
+
+       /* Parent */
+
+       close(fildes[1]);
+       buffer = alloca(bufsize);
+
+       if (!pwordexp)
+               /* Quoted - no field splitting */
+       {
+               while (1) {
+                       if ((buflen = read(fildes[0], buffer, bufsize)) < 1) {
+                               if (waitpid(pid, &status, WNOHANG) == 0)
+                                       continue;
+                               if ((buflen = read(fildes[0], buffer, bufsize)) < 1)
+                                       break;
+                       }
+
+                       maxnewlines += buflen;
+
+                       *word = w_addmem(*word, word_length, max_length, buffer, buflen);
+                       if (*word == NULL)
+                               goto no_space;
+               }
+       } else
+               /* Not quoted - split fields */
+       {
+               int copying = 0;
+
+               /* 'copying' is:
+                *  0 when searching for first character in a field not IFS white space
+                *  1 when copying the text of a field
+                *  2 when searching for possible non-whitespace IFS
+                *  3 when searching for non-newline after copying field
+                */
+
+               while (1) {
+                       if ((buflen = read(fildes[0], buffer, bufsize)) < 1) {
+                               if (waitpid(pid, &status, WNOHANG) == 0)
+                                       continue;
+                               if ((buflen = read(fildes[0], buffer, bufsize)) < 1)
+                                       break;
+                       }
+
+                       for (i = 0; i < buflen; ++i) {
+                               if (strchr(ifs, buffer[i]) != NULL) {
+                                       /* Current character is IFS */
+                                       if (strchr(ifs_white, buffer[i]) == NULL) {
+                                               /* Current character is IFS but not whitespace */
+                                               if (copying == 2) {
+                                                       /*            current character
+                                                        *                   |
+                                                        *                   V
+                                                        * eg: text<space><comma><space>moretext
+                                                        *
+                                                        * So, strip whitespace IFS (like at the start)
+                                                        */
+                                                       copying = 0;
+                                                       continue;
+                                               }
+
+                                               copying = 0;
+                                               /* fall through and delimit field.. */
+                                       } else {
+                                               if (buffer[i] == '\n') {
+                                                       /* Current character is (IFS) newline */
+
+                                                       /* If copying a field, this is the end of it,
+                                                          but maybe all that's left is trailing newlines.
+                                                          So start searching for a non-newline. */
+                                                       if (copying == 1)
+                                                               copying = 3;
+
+                                                       continue;
+                                               } else {
+                                                       /* Current character is IFS white space, but
+                                                          not a newline */
+
+                                                       /* If not either copying a field or searching
+                                                          for non-newline after a field, ignore it */
+                                                       if (copying != 1 && copying != 3)
+                                                               continue;
+
+                                                       /* End of field (search for non-ws IFS afterwards) */
+                                                       copying = 2;
+                                               }
+                                       }
+
+                                       /* First IFS white space (non-newline), or IFS non-whitespace.
+                                        * Delimit the field.  Nulls are converted by w_addword. */
+                                       if (w_addword(pwordexp, *word) == WRDE_NOSPACE)
+                                               goto no_space;
+
+                                       *word = w_newword(word_length, max_length);
+
+                                       maxnewlines = 0;
+                                       /* fall back round the loop.. */
+                               } else {
+                                       /* Not IFS character */
+
+                                       if (copying == 3) {
+                                               /* Nothing but (IFS) newlines since the last field,
+                                                  so delimit it here before starting new word */
+                                               if (w_addword(pwordexp, *word) == WRDE_NOSPACE)
+                                                       goto no_space;
+
+                                               *word = w_newword(word_length, max_length);
+                                       }
+
+                                       copying = 1;
+
+                                       if (buffer[i] == '\n')  /* happens if newline not in IFS */
+                                               maxnewlines++;
+                                       else
+                                               maxnewlines = 0;
+
+                                       *word = w_addchar(*word, word_length, max_length,
+                                                                         buffer[i]);
+                                       if (*word == NULL)
+                                               goto no_space;
+                               }
+                       }
+               }
+       }
+
+       /* Chop off trailing newlines (required by POSIX.2)  */
+       /* Ensure we don't go back further than the beginning of the
+          substitution (i.e. remove maxnewlines bytes at most) */
+       while (maxnewlines-- != 0 &&
+                  *word_length > 0 && (*word)[*word_length - 1] == '\n') {
+               (*word)[--*word_length] = '\0';
+
+               /* If the last word was entirely newlines, turn it into a new word
+                * which can be ignored if there's nothing following it. */
+               if (*word_length == 0) {
+                       free(*word);
+                       *word = w_newword(word_length, max_length);
+                       break;
+               }
+       }
+
+       close(fildes[0]);
+
+       /* Check for syntax error (re-execute but with "-n" flag) */
+       if (buflen < 1 && status != 0) {
+               if ((pid = fork()) < 0) {
+                       /* Bad */
+                       return WRDE_NOSPACE;
+               }
+
+               if (pid == 0) {
+                       fildes[0] = fildes[1] = -1;
+                       exec_comm_child(comm, fildes, 0, 1);
+               }
+
+               if (waitpid(pid, &status, 0) == pid && status != 0)
+                       return WRDE_SYNTAX;
+       }
+
+       return 0;
+
+  no_space:
+       kill(pid, SIGKILL);
+       waitpid(pid, NULL, 0);
+       close(fildes[0]);
+       return WRDE_NOSPACE;
+}
+
+static int
+parse_comm(char **word, size_t * word_length, size_t * max_length,
+                  const char *words, size_t * offset, int flags,
+                  wordexp_t * pwordexp, const char *ifs, const char *ifs_white)
+{
+       /* We are poised just after "$(" */
+       int paren_depth = 1;
+       int error = 0;
+       int quoted = 0;                         /* 1 for singly-quoted, 2 for doubly-quoted */
+       size_t comm_length;
+       size_t comm_maxlen;
+       char *comm = w_newword(&comm_length, &comm_maxlen);
+
+       for (; words[*offset]; ++(*offset)) {
+               switch (words[*offset]) {
+               case '\'':
+                       if (quoted == 0)
+                               quoted = 1;
+                       else if (quoted == 1)
+                               quoted = 0;
+
+                       break;
+
+               case '"':
+                       if (quoted == 0)
+                               quoted = 2;
+                       else if (quoted == 2)
+                               quoted = 0;
+
+                       break;
+
+               case ')':
+                       if (!quoted && --paren_depth == 0) {
+                               /* Go -- give script to the shell */
+                               if (comm) {
+                                       error = exec_comm(comm, word, word_length, max_length,
+                                                                         flags, pwordexp, ifs, ifs_white);
+                                       free(comm);
+                               }
+
+                               return error;
+                       }
+
+                       /* This is just part of the script */
+                       break;
+
+               case '(':
+                       if (!quoted)
+                               ++paren_depth;
+               }
+
+               comm = w_addchar(comm, &comm_length, &comm_maxlen, words[*offset]);
+               if (comm == NULL)
+                       return WRDE_NOSPACE;
+       }
+
+       /* Premature end */
+       if (comm)
+               free(comm);
+
+       return WRDE_SYNTAX;
+}
+
+static int
+parse_backtick(char **word, size_t * word_length, size_t * max_length,
+                          const char *words, size_t * offset, int flags,
+                          wordexp_t * pwordexp, const char *ifs,
+                          const char *ifs_white)
+{
+       /* We are poised just after "`" */
+       int error;
+       int squoting = 0;
+       size_t comm_length;
+       size_t comm_maxlen;
+       char *comm = w_newword(&comm_length, &comm_maxlen);
+
+       for (; words[*offset]; ++(*offset)) {
+               switch (words[*offset]) {
+               case '`':
+                       /* Go -- give the script to the shell */
+                       error = exec_comm(comm, word, word_length, max_length, flags,
+                                                         pwordexp, ifs, ifs_white);
+                       free(comm);
+                       return error;
+
+               case '\\':
+                       if (squoting) {
+                               error = parse_qtd_backslash(&comm, &comm_length, &comm_maxlen,
+                                                                               words, offset);
+
+                               if (error) {
+                                       free(comm);
+                                       return error;
+                               }
+
+                               break;
+                       }
+
+                       ++(*offset);
+                       error = parse_backslash(&comm, &comm_length, &comm_maxlen, words,
+                                                               offset);
+
+                       if (error) {
+                               free(comm);
+                               return error;
+                       }
+
+                       break;
+
+               case '\'':
+                       squoting = 1 - squoting;
+               default:
+                       comm = w_addchar(comm, &comm_length, &comm_maxlen,
+                                                 words[*offset]);
+                       if (comm == NULL)
+                               return WRDE_NOSPACE;
+               }
+       }
+
+       /* Premature end */
+       free(comm);
+       return WRDE_SYNTAX;
+}
+
+static int
+parse_param(char **word, size_t * word_length, size_t * max_length,
+                       const char *words, size_t * offset, int flags,
+                       wordexp_t * pwordexp, const char *ifs, const char *ifs_white,
+                       int quoted)
+{
+       /* We are poised just after "$" */
+       enum action {
+               ACT_NONE,
+               ACT_RP_SHORT_LEFT = '#',
+               ACT_RP_LONG_LEFT = 'L',
+               ACT_RP_SHORT_RIGHT = '%',
+               ACT_RP_LONG_RIGHT = 'R',
+               ACT_NULL_ERROR = '?',
+               ACT_NULL_SUBST = '-',
+               ACT_NONNULL_SUBST = '+',
+               ACT_NULL_ASSIGN = '='
+       };
+       size_t env_length;
+       size_t env_maxlen;
+       size_t pat_length;
+       size_t pat_maxlen;
+       size_t start = *offset;
+       char *env;
+       char *pattern;
+       char *value = NULL;
+       enum action action = ACT_NONE;
+       int depth = 0;
+       int colon_seen = 0;
+       int seen_hash = 0;
+       int free_value = 0;
+       int pattern_is_quoted = 0;      /* 1 for singly-quoted, 2 for doubly-quoted */
+       int error;
+       int special = 0;
+       char buffer[21];
+       int brace = words[*offset] == '{';
+
+       env = w_newword(&env_length, &env_maxlen);
+       pattern = w_newword(&pat_length, &pat_maxlen);
+
+       if (brace)
+               ++ * offset;
+
+       /* First collect the parameter name. */
+
+       if (words[*offset] == '#') {
+               seen_hash = 1;
+               if (!brace)
+                       goto envsubst;
+               ++*offset;
+       }
+
+       if (isalpha(words[*offset]) || words[*offset] == '_') {
+               /* Normal parameter name. */
+               do {
+                       env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
+                       if (env == NULL)
+                               goto no_space;
+               }
+               while (isalnum(words[++*offset]) || words[*offset] == '_');
+       } else if (isdigit(words[*offset])) {
+               /* Numeric parameter name. */
+               special = 1;
+               do {
+                       env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
+                       if (env == NULL)
+                               goto no_space;
+                       if (!brace)
+                               goto envsubst;
+               }
+               while (isdigit(words[++*offset]));
+       } else if (strchr("*@$", words[*offset]) != NULL) {
+               /* Special parameter. */
+               special = 1;
+               env = w_addchar(env, &env_length, &env_maxlen, words[*offset]);
+               if (env == NULL)
+                       goto no_space;
+               ++*offset;
+       } else {
+               if (brace)
+                       goto syntax;
+       }
+
+       if (brace) {
+               /* Check for special action to be applied to the value. */
+               switch (words[*offset]) {
+               case '}':
+                       /* Evaluate. */
+                       goto envsubst;
+
+               case '#':
+                       action = ACT_RP_SHORT_LEFT;
+                       if (words[1 + *offset] == '#') {
+                               ++*offset;
+                               action = ACT_RP_LONG_LEFT;
+                       }
+                       break;
+
+               case '%':
+                       action = ACT_RP_SHORT_RIGHT;
+                       if (words[1 + *offset] == '%') {
+                               ++*offset;
+                               action = ACT_RP_LONG_RIGHT;
+                       }
+                       break;
+
+               case ':':
+                       if (strchr("-=?+", words[1 + *offset]) == NULL)
+                               goto syntax;
+
+                       colon_seen = 1;
+                       action = words[++*offset];
+                       break;
+
+               case '-':
+               case '=':
+               case '?':
+               case '+':
+                       action = words[*offset];
+                       break;
+
+               default:
+                       goto syntax;
+               }
+
+               /* Now collect the pattern, but don't expand it yet. */
+               ++*offset;
+               for (; words[*offset]; ++(*offset)) {
+                       switch (words[*offset]) {
+                       case '{':
+                               if (!pattern_is_quoted)
+                                       ++depth;
+                               break;
+
+                       case '}':
+                               if (!pattern_is_quoted) {
+                                       if (depth == 0)
+                                               goto envsubst;
+                                       --depth;
+                               }
+                               break;
+
+                       case '\\':
+                               if (pattern_is_quoted)
+                                       /* Quoted; treat as normal character. */
+                                       break;
+
+                               /* Otherwise, it's an escape: next character is literal. */
+                               if (words[++*offset] == '\0')
+                                       goto syntax;
+
+                               pattern = w_addchar(pattern, &pat_length, &pat_maxlen, '\\');
+                               if (pattern == NULL)
+                                       goto no_space;
+
+                               break;
+
+                       case '\'':
+                               if (pattern_is_quoted == 0)
+                                       pattern_is_quoted = 1;
+                               else if (pattern_is_quoted == 1)
+                                       pattern_is_quoted = 0;
+
+                               break;
+
+                       case '"':
+                               if (pattern_is_quoted == 0)
+                                       pattern_is_quoted = 2;
+                               else if (pattern_is_quoted == 2)
+                                       pattern_is_quoted = 0;
+
+                               break;
+                       }
+
+                       pattern = w_addchar(pattern, &pat_length, &pat_maxlen,
+                                                               words[*offset]);
+                       if (pattern == NULL)
+                               goto no_space;
+               }
+       }
+
+       /* End of input string -- remember to reparse the character that we
+        * stopped at.  */
+       --(*offset);
+
+  envsubst:
+       if (words[start] == '{' && words[*offset] != '}')
+               goto syntax;
+
+       if (env == NULL) {
+               if (seen_hash) {
+                       /* $# expands to the number of positional parameters */
+                       buffer[20] = '\0';
+                       value = _itoa(__libc_argc - 1, &buffer[20]);
+                       seen_hash = 0;
+               } else {
+                       /* Just $ on its own */
+                       *offset = start - 1;
+                       *word = w_addchar(*word, word_length, max_length, '$');
+                       return *word ? 0 : WRDE_NOSPACE;
+               }
+       }
+       /* Is it a numeric parameter? */
+       else if (isdigit(env[0])) {
+               int n = atoi(env);
+
+               if (n >= __libc_argc)
+                       /* Substitute NULL. */
+                       value = NULL;
+               else
+                       /* Replace with appropriate positional parameter. */
+                       value = __libc_argv[n];
+       }
+       /* Is it a special parameter? */
+       else if (special) {
+               /* Is it `$$'? */
+               if (*env == '$') {
+                       buffer[20] = '\0';
+                       value = _itoa(getpid(), &buffer[20]);
+               }
+               /* Is it `${#*}' or `${#@}'? */
+               else if ((*env == '*' || *env == '@') && seen_hash) {
+                       buffer[20] = '\0';
+                       value = _itoa(__libc_argc > 0 ? __libc_argc - 1 : 0,
+                                                          &buffer[20]);
+                       *word = w_addstr(*word, word_length, max_length, value);
+                       free(env);
+                       if (pattern)
+                               free(pattern);
+                       return *word ? 0 : WRDE_NOSPACE;
+               }
+               /* Is it `$*' or `$@' (unquoted) ? */
+               else if (*env == '*' || (*env == '@' && !quoted)) {
+                       size_t plist_len = 0;
+                       int p;
+                       char *end;
+
+                       /* Build up value parameter by parameter (copy them) */
+                       for (p = 1; __libc_argv[p]; ++p)
+                               plist_len += strlen(__libc_argv[p]) + 1;        /* for space */
+                       value = malloc(plist_len);
+                       if (value == NULL)
+                               goto no_space;
+                       end = value;
+                       *end = 0;
+                       for (p = 1; __libc_argv[p]; ++p) {
+                               if (p > 1)
+                                       *end++ = ' ';
+                               end = stpcpy(end, __libc_argv[p]);
+                       }
+
+                       free_value = 1;
+               } else {
+                       /* Must be a quoted `$@' */
+                       assert(*env == '@' && quoted);
+
+                       /* Each parameter is a separate word ("$@") */
+                       if (__libc_argc == 2)
+                               value = __libc_argv[1];
+                       else if (__libc_argc > 2) {
+                               int p;
+
+                               /* Append first parameter to current word. */
+                               value = w_addstr(*word, word_length, max_length,
+                                                                __libc_argv[1]);
+                               if (value == NULL || w_addword(pwordexp, value))
+                                       goto no_space;
+
+                               for (p = 2; __libc_argv[p + 1]; p++) {
+                                       char *newword = strdup(__libc_argv[p]);
+
+                                       if (newword == NULL || w_addword(pwordexp, newword))
+                                               goto no_space;
+                               }
+
+                               /* Start a new word with the last parameter. */
+                               *word = w_newword(word_length, max_length);
+                               value = __libc_argv[p];
+                       } else {
+                               free(env);
+                               free(pattern);
+                               return 0;
+                       }
+               }
+       } else
+               value = getenv(env);
+
+       if (value == NULL && (flags & WRDE_UNDEF)) {
+               /* Variable not defined. */
+               error = WRDE_BADVAL;
+               goto do_error;
+       }
+
+       if (action != ACT_NONE) {
+               int expand_pattern = 0;
+
+               /* First, find out if we need to expand pattern (i.e. if we will
+                * use it). */
+               switch (action) {
+               case ACT_RP_SHORT_LEFT:
+               case ACT_RP_LONG_LEFT:
+               case ACT_RP_SHORT_RIGHT:
+               case ACT_RP_LONG_RIGHT:
+                       /* Always expand for these. */
+                       expand_pattern = 1;
+                       break;
+
+               case ACT_NULL_ERROR:
+               case ACT_NULL_SUBST:
+               case ACT_NULL_ASSIGN:
+                       if (!value || (!*value && colon_seen))
+                               /* If param is unset, or set but null and a colon has been seen,
+                                  the expansion of the pattern will be needed. */
+                               expand_pattern = 1;
+
+                       break;
+
+               case ACT_NONNULL_SUBST:
+                       /* Expansion of word will be needed if parameter is set and not null,
+                          or set null but no colon has been seen. */
+                       if (value && (*value || !colon_seen))
+                               expand_pattern = 1;
+
+                       break;
+
+               default:
+                       assert(!"Unrecognised action!");
+               }
+
+               if (expand_pattern) {
+                       /* We need to perform tilde expansion, parameter expansion,
+                          command substitution, and arithmetic expansion.  We also
+                          have to be a bit careful with wildcard characters, as
+                          pattern might be given to fnmatch soon.  To do this, we
+                          convert quotes to escapes. */
+
+                       char *expanded;
+                       size_t exp_len;
+                       size_t exp_maxl;
+                       char *p;
+                       int quoted = 0;         /* 1: single quotes; 2: double */
+
+                       expanded = w_newword(&exp_len, &exp_maxl);
+                       for (p = pattern; p && *p; p++) {
+                               size_t offset;
+
+                               switch (*p) {
+                               case '"':
+                                       if (quoted == 2)
+                                               quoted = 0;
+                                       else if (quoted == 0)
+                                               quoted = 2;
+                                       else
+                                               break;
+
+                                       continue;
+
+                               case '\'':
+                                       if (quoted == 1)
+                                               quoted = 0;
+                                       else if (quoted == 0)
+                                               quoted = 1;
+                                       else
+                                               break;
+
+                                       continue;
+
+                               case '*':
+                               case '?':
+                                       if (quoted) {
+                                               /* Convert quoted wildchar to escaped wildchar. */
+                                               expanded = w_addchar(expanded, &exp_len,
+                                                                                        &exp_maxl, '\\');
+
+                                               if (expanded == NULL)
+                                                       goto no_space;
+                                       }
+                                       break;
+
+                               case '$':
+                                       offset = 0;
+                                       error = parse_dollars(&expanded, &exp_len, &exp_maxl, p,
+                                                                         &offset, flags, NULL, NULL, NULL, 1);
+                                       if (error) {
+                                               if (free_value)
+                                                       free(value);
+
+                                               if (expanded)
+                                                       free(expanded);
+
+                                               goto do_error;
+                                       }
+
+                                       p += offset;
+                                       continue;
+
+                               case '~':
+                                       if (quoted || exp_len)
+                                               break;
+
+                                       offset = 0;
+                                       error = parse_tilde(&expanded, &exp_len, &exp_maxl, p,
+                                                                               &offset, 0);
+                                       if (error) {
+                                               if (free_value)
+                                                       free(value);
+
+                                               if (expanded)
+                                                       free(expanded);
+
+                                               goto do_error;
+                                       }
+
+                                       p += offset;
+                                       continue;
+
+                               case '\\':
+                                       expanded = w_addchar(expanded, &exp_len, &exp_maxl, '\\');
+                                       ++p;
+                                       assert(*p);     /* checked when extracted initially */
+                                       if (expanded == NULL)
+                                               goto no_space;
+                               }
+
+                               expanded = w_addchar(expanded, &exp_len, &exp_maxl, *p);
+
+                               if (expanded == NULL)
+                                       goto no_space;
+                       }
+
+                       if (pattern)
+                               free(pattern);
+
+                       pattern = expanded;
+               }
+
+               switch (action) {
+               case ACT_RP_SHORT_LEFT:
+               case ACT_RP_LONG_LEFT:
+               case ACT_RP_SHORT_RIGHT:
+               case ACT_RP_LONG_RIGHT:
+               {
+                       char *p;
+                       char c;
+                       char *end;
+
+                       if (value == NULL || pattern == NULL || *pattern == '\0')
+                               break;
+
+                       end = value + strlen(value);
+
+                       switch (action) {
+                       case ACT_RP_SHORT_LEFT:
+                               for (p = value; p <= end; ++p) {
+                                       c = *p;
+                                       *p = '\0';
+                                       if (fnmatch(pattern, value, 0) != FNM_NOMATCH) {
+                                               *p = c;
+                                               if (free_value) {
+                                                       char *newval = strdup(p);
+
+                                                       if (newval == NULL) {
+                                                               free(value);
+                                                               goto no_space;
+                                                       }
+                                                       free(value);
+                                                       value = newval;
+                                               } else
+                                                       value = p;
+                                               break;
+                                       }
+                                       *p = c;
+                               }
+
+                               break;
+
+                       case ACT_RP_LONG_LEFT:
+                               for (p = end; p >= value; --p) {
+                                       c = *p;
+                                       *p = '\0';
+                                       if (fnmatch(pattern, value, 0) != FNM_NOMATCH) {
+                                               *p = c;
+                                               if (free_value) {
+                                                       char *newval = strdup(p);
+
+                                                       if (newval == NULL) {
+                                                               free(value);
+                                                               goto no_space;
+                                                       }
+                                                       free(value);
+                                                       value = newval;
+                                               } else
+                                                       value = p;
+                                               break;
+                                       }
+                                       *p = c;
+                               }
+
+                               break;
+
+                       case ACT_RP_SHORT_RIGHT:
+                               for (p = end; p >= value; --p) {
+                                       if (fnmatch(pattern, p, 0) != FNM_NOMATCH) {
+                                               char *newval;
+
+                                               newval = malloc(p - value + 1);
+
+                                               if (newval == NULL) {
+                                                       if (free_value)
+                                                               free(value);
+                                                       goto no_space;
+                                               }
+
+                                               *(char *) mempcpy(newval, value, p - value) = '\0';
+                                               if (free_value)
+                                                       free(value);
+                                               value = newval;
+                                               free_value = 1;
+                                               break;
+                                       }
+                               }
+
+                               break;
+
+                       case ACT_RP_LONG_RIGHT:
+                               for (p = value; p <= end; ++p) {
+                                       if (fnmatch(pattern, p, 0) != FNM_NOMATCH) {
+                                               char *newval;
+
+                                               newval = malloc(p - value + 1);
+
+                                               if (newval == NULL) {
+                                                       if (free_value)
+                                                               free(value);
+                                                       goto no_space;
+                                               }
+
+                                               *(char *) mempcpy(newval, value, p - value) = '\0';
+                                               if (free_value)
+                                                       free(value);
+                                               value = newval;
+                                               free_value = 1;
+                                               break;
+                                       }
+                               }
+
+                               break;
+
+                       default:
+                               break;
+                       }
+
+                       break;
+               }
+
+               case ACT_NULL_ERROR:
+                       if (value && *value)
+                               /* Substitute parameter */
+                               break;
+
+                       error = 0;
+                       if (!colon_seen && value)
+                               /* Substitute NULL */
+                               ;
+                       else if (*pattern)
+                               fprintf(stderr, "%s: %s\n", env, pattern);
+                       else {
+                               fprintf(stderr, "%s: parameter null or not set\n", env);
+                               error = WRDE_BADVAL;
+                       }
+
+                       if (free_value)
+                               free(value);
+                       goto do_error;
+
+               case ACT_NULL_SUBST:
+                       if (value && *value)
+                               /* Substitute parameter */
+                               break;
+
+                       if (free_value && value)
+                               free(value);
+
+                       if (!colon_seen && value)
+                               /* Substitute NULL */
+                               goto success;
+
+                       value = pattern ? strdup(pattern) : pattern;
+                       free_value = 1;
+
+                       if (pattern && !value)
+                               goto no_space;
+
+                       break;
+
+               case ACT_NONNULL_SUBST:
+                       if (value && (*value || !colon_seen)) {
+                               if (free_value && value)
+                                       free(value);
+
+                               value = pattern ? strdup(pattern) : pattern;
+                               free_value = 1;
+
+                               if (pattern && !value)
+                                       goto no_space;
+
+                               break;
+                       }
+
+                       /* Substitute NULL */
+                       if (free_value)
+                               free(value);
+                       goto success;
+
+               case ACT_NULL_ASSIGN:
+                       if (value && *value)
+                               /* Substitute parameter */
+                               break;
+
+                       if (!colon_seen && value) {
+                               /* Substitute NULL */
+                               if (free_value)
+                                       free(value);
+                               goto success;
+                       }
+
+                       if (free_value && value)
+                               free(value);
+
+                       value = pattern ? strdup(pattern) : pattern;
+                       free_value = 1;
+
+                       if (pattern && !value)
+                               goto no_space;
+
+                       setenv(env, value, 1);
+                       break;
+
+               default:
+                       assert(!"Unrecognised action!");
+               }
+       }
+
+       free(env);
+       env = NULL;
+       free(pattern);
+       pattern = NULL;
+
+       if (seen_hash) {
+               char param_length[21];
+
+               param_length[20] = '\0';
+               *word = w_addstr(*word, word_length, max_length,
+                                                _itoa(value ? strlen(value) : 0,
+                                                                       &param_length[20]));
+               if (free_value) {
+                       assert(value != NULL);
+                       free(value);
+               }
+
+               return *word ? 0 : WRDE_NOSPACE;
+       }
+
+       if (value == NULL)
+               return 0;
+
+       if (quoted || !pwordexp) {
+               /* Quoted - no field split */
+               *word = w_addstr(*word, word_length, max_length, value);
+               if (free_value)
+                       free(value);
+
+               return *word ? 0 : WRDE_NOSPACE;
+       } else {
+               /* Need to field-split */
+               char *value_copy = strdup(value);       /* Don't modify value */
+               char *field_begin = value_copy;
+               int seen_nonws_ifs = 0;
+
+               if (free_value)
+                       free(value);
+
+               if (value_copy == NULL)
+                       goto no_space;
+
+               do {
+                       char *field_end = field_begin;
+                       char *next_field;
+
+                       /* If this isn't the first field, start a new word */
+                       if (field_begin != value_copy) {
+                               if (w_addword(pwordexp, *word) == WRDE_NOSPACE) {
+                                       free(value_copy);
+                                       goto no_space;
+                               }
+
+                               *word = w_newword(word_length, max_length);
+                       }
+
+                       /* Skip IFS whitespace before the field */
+                       field_begin += strspn(field_begin, ifs_white);
+
+                       if (!seen_nonws_ifs && *field_begin == 0)
+                               /* Nothing but whitespace */
+                               break;
+
+                       /* Search for the end of the field */
+                       field_end = field_begin + strcspn(field_begin, ifs);
+
+                       /* Set up pointer to the character after end of field and
+                          skip whitespace IFS after it. */
+                       next_field = field_end + strspn(field_end, ifs_white);
+
+                       /* Skip at most one non-whitespace IFS character after the field */
+                       seen_nonws_ifs = 0;
+                       if (*next_field && strchr(ifs, *next_field)) {
+                               seen_nonws_ifs = 1;
+                               next_field++;
+                       }
+
+                       /* Null-terminate it */
+                       *field_end = 0;
+
+                       /* Tag a copy onto the current word */
+                       *word = w_addstr(*word, word_length, max_length, field_begin);
+
+                       if (*word == NULL && *field_begin != '\0') {
+                               free(value_copy);
+                               goto no_space;
+                       }
+
+                       field_begin = next_field;
+               }
+               while (seen_nonws_ifs || *field_begin);
+
+               free(value_copy);
+       }
+
+       return 0;
+
+  success:
+       error = 0;
+       goto do_error;
+
+  no_space:
+       error = WRDE_NOSPACE;
+       goto do_error;
+
+  syntax:
+       error = WRDE_SYNTAX;
+
+  do_error:
+       if (env)
+               free(env);
+
+       if (pattern)
+               free(pattern);
+
+       return error;
+}
+#else
+static inline int
+parse_backtick(char **word, size_t * word_length, size_t * max_length,
+                          const char *words, size_t * offset, int flags,
+                          wordexp_t * pwordexp, const char *ifs,
+                          const char *ifs_white)
+{
+       return 0;
+}
+#endif
+
+static int
+parse_dollars(char **word, size_t * word_length, size_t * max_length,
+                         const char *words, size_t * offset, int flags,
+                         wordexp_t * pwordexp, const char *ifs, const char *ifs_white,
+                         int quoted)
+{
+       /* We are poised _at_ "$" */
+       switch (words[1 + *offset]) {
+       case '"':
+       case '\'':
+       case 0:
+               *word = w_addchar(*word, word_length, max_length, '$');
+               return *word ? 0 : WRDE_NOSPACE;
+
+#ifdef __WORDEXP_FULL
+       case '(':
+               if (words[2 + *offset] == '(') {
+                       /* Differentiate between $((1+3)) and $((echo);(ls)) */
+                       int i = 3 + *offset;
+                       int depth = 0;
+
+                       while (words[i] && !(depth == 0 && words[i] == ')')) {
+                               if (words[i] == '(')
+                                       ++depth;
+                               else if (words[i] == ')')
+                                       --depth;
+
+                               ++i;
+                       }
+
+                       if (words[i] == ')' && words[i + 1] == ')') {
+                               (*offset) += 3;
+                               /* Call parse_arith -- 0 is for "no brackets" */
+                               return parse_arith(word, word_length, max_length, words,
+                                                                  offset, flags, 0);
+                       }
+               }
+
+               if (flags & WRDE_NOCMD)
+                       return WRDE_CMDSUB;
+
+               (*offset) += 2;
+               return parse_comm(word, word_length, max_length, words, offset,
+                                                 flags, quoted ? NULL : pwordexp, ifs, ifs_white);
+
+       case '[':
+               (*offset) += 2;
+               /* Call parse_arith -- 1 is for "brackets" */
+               return parse_arith(word, word_length, max_length, words, offset,
+                                                  flags, 1);
+
+       case '{':
+       default:
+               ++(*offset);                    /* parse_param needs to know if "{" is there */
+               return parse_param(word, word_length, max_length, words, offset,
+                                                  flags, pwordexp, ifs, ifs_white, quoted);
+#else
+       default:
+               ++(*offset);                    /* parse_param needs to know if "{" is there */
+               return 0;
+#endif
+       }
+}
+
+static int
+parse_dquote(char **word, size_t * word_length, size_t * max_length,
+                        const char *words, size_t * offset, int flags,
+                        wordexp_t * pwordexp, const char *ifs, const char *ifs_white)
+{
+       /* We are poised just after a double-quote */
+       int error;
+
+       for (; words[*offset]; ++(*offset)) {
+               switch (words[*offset]) {
+               case '"':
+                       return 0;
+
+               case '$':
+                       error = parse_dollars(word, word_length, max_length, words, offset,
+                                                         flags, pwordexp, ifs, ifs_white, 1);
+                       /* The ``1'' here is to tell parse_dollars not to
+                        * split the fields.  It may need to, however ("$@").
+                        */
+                       if (error)
+                               return error;
+
+                       break;
+
+               case '`':
+                       if (flags & WRDE_NOCMD)
+                               return WRDE_CMDSUB;
+
+                       ++(*offset);
+                       error = parse_backtick(word, word_length, max_length, words,
+                                                                  offset, flags, NULL, NULL, NULL);
+                       /* The first NULL here is to tell parse_backtick not to
+                        * split the fields.
+                        */
+                       if (error)
+                               return error;
+
+                       break;
+
+               case '\\':
+                       error = parse_qtd_backslash(word, word_length, max_length, words,
+                                                                       offset);
+
+                       if (error)
+                               return error;
+
+                       break;
+
+               default:
+                       *word = w_addchar(*word, word_length, max_length, words[*offset]);
+                       if (*word == NULL)
+                               return WRDE_NOSPACE;
+               }
+       }
+
+       /* Unterminated string */
+       return WRDE_SYNTAX;
+}
+
+/*
+ * wordfree() is to be called after pwordexp is finished with.
+ */
+
+void wordfree(wordexp_t * pwordexp)
+{
+
+       /* wordexp can set pwordexp to NULL */
+       if (pwordexp && pwordexp->we_wordv) {
+               char **wordv = pwordexp->we_wordv;
+
+               for (wordv += pwordexp->we_offs; *wordv; ++wordv)
+                       free(*wordv);
+
+               free(pwordexp->we_wordv);
+               pwordexp->we_wordv = NULL;
+       }
+}
+
+/*
+ * wordexp()
+ */
+
+int wordexp(const char *words, wordexp_t * we, int flags)
+{
+       size_t words_offset;
+       size_t word_length;
+       size_t max_length;
+       char *word = w_newword(&word_length, &max_length);
+       int error;
+       char *ifs;
+       char ifs_white[4];
+       wordexp_t old_word = *we;
+
+       if (flags & WRDE_REUSE) {
+               /* Minimal implementation of WRDE_REUSE for now */
+               wordfree(we);
+               old_word.we_wordv = NULL;
+       }
+
+       if ((flags & WRDE_APPEND) == 0) {
+               we->we_wordc = 0;
+
+               if (flags & WRDE_DOOFFS) {
+                       we->we_wordv = calloc(1 + we->we_offs, sizeof(char *));
+                       if (we->we_wordv == NULL) {
+                               error = WRDE_NOSPACE;
+                               goto do_error;
+                       }
+               } else {
+                       we->we_wordv = calloc(1, sizeof(char *));
+                       if (we->we_wordv == NULL) {
+                               error = WRDE_NOSPACE;
+                               goto do_error;
+                       }
+
+                       we->we_offs = 0;
+               }
+       }
+
+       /* Find out what the field separators are.
+        * There are two types: whitespace and non-whitespace.
+        */
+       ifs = getenv("IFS");
+
+       if (!ifs)
+               /* IFS unset - use <space><tab><newline>. */
+               ifs = strcpy(ifs_white, " \t\n");
+       else {
+               char *ifsch = ifs;
+               char *whch = ifs_white;
+
+               /* Start off with no whitespace IFS characters */
+               ifs_white[0] = '\0';
+
+               while (*ifsch != '\0') {
+                       if ((*ifsch == ' ') || (*ifsch == '\t') || (*ifsch == '\n')) {
+                               /* Whitespace IFS.  See first whether it is already in our
+                                  collection.  */
+                               char *runp = ifs_white;
+
+                               while (runp < whch && *runp != '\0' && *runp != *ifsch)
+                                       ++runp;
+
+                               if (runp == whch)
+                                       *whch++ = *ifsch;
+                       }
+
+                       ++ifsch;
+               }
+               *whch = '\0';
+       }
+
+       for (words_offset = 0; words[words_offset]; ++words_offset)
+               switch (words[words_offset]) {
+               case '\\':
+                       error = parse_backslash(&word, &word_length, &max_length, words,
+                                                               &words_offset);
+
+                       if (error)
+                               goto do_error;
+
+                       break;
+
+               case '$':
+                       error = parse_dollars(&word, &word_length, &max_length, words,
+                                                                 &words_offset, flags, we, ifs, ifs_white,
+                                                                 0);
+
+                       if (error)
+                               goto do_error;
+
+                       break;
+
+               case '`':
+                       if (flags & WRDE_NOCMD) {
+                               error = WRDE_CMDSUB;
+                               goto do_error;
+                       }
+
+                       ++words_offset;
+                       error = parse_backtick(&word, &word_length, &max_length, words,
+                                                                  &words_offset, flags, we, ifs,
+                                                                  ifs_white);
+
+                       if (error)
+                               goto do_error;
+
+                       break;
+
+               case '"':
+                       ++words_offset;
+                       error = parse_dquote(&word, &word_length, &max_length, words,
+                                                                &words_offset, flags, we, ifs, ifs_white);
+
+                       if (error)
+                               goto do_error;
+
+                       if (!word_length) {
+                               error = w_addword(we, NULL);
+
+                               if (error)
+                                       return error;
+                       }
+
+                       break;
+
+               case '\'':
+                       ++words_offset;
+                       error = parse_squote(&word, &word_length, &max_length, words,
+                                                                &words_offset);
+
+                       if (error)
+                               goto do_error;
+
+                       if (!word_length) {
+                               error = w_addword(we, NULL);
+
+                               if (error)
+                                       return error;
+                       }
+
+                       break;
+
+               case '~':
+                       error = parse_tilde(&word, &word_length, &max_length, words,
+                                                               &words_offset, we->we_wordc);
+
+                       if (error)
+                               goto do_error;
+
+                       break;
+
+               case '*':
+               case '[':
+               case '?':
+                       error = parse_glob(&word, &word_length, &max_length, words,
+                                                          &words_offset, flags, we, ifs, ifs_white);
+
+                       if (error)
+                               goto do_error;
+
+                       break;
+
+               default:
+                       /* Is it a word separator? */
+                       if (strchr(" \t", words[words_offset]) == NULL) {
+                               char ch = words[words_offset];
+
+                               /* Not a word separator -- but is it a valid word char? */
+                               if (strchr("\n|&;<>(){}", ch)) {
+                                       /* Fail */
+                                       error = WRDE_BADCHAR;
+                                       goto do_error;
+                               }
+
+                               /* "Ordinary" character -- add it to word */
+                               word = w_addchar(word, &word_length, &max_length, ch);
+                               if (word == NULL) {
+                                       error = WRDE_NOSPACE;
+                                       goto do_error;
+                               }
+
+                               break;
+                       }
+
+                       /* If a word has been delimited, add it to the list. */
+                       if (word != NULL) {
+                               error = w_addword(we, word);
+                               if (error)
+                                       goto do_error;
+                       }
+
+                       word = w_newword(&word_length, &max_length);
+               }
+
+       /* End of string */
+
+       /* There was a word separator at the end */
+       if (word == NULL)                       /* i.e. w_newword */
+               return 0;
+
+       /* There was no field separator at the end */
+       return w_addword(we, word);
+
+  do_error:
+       /* Error:
+        *  free memory used (unless error is WRDE_NOSPACE), and
+        *  set we members back to what they were.
+        */
+
+       if (word != NULL)
+               free(word);
+
+       if (error == WRDE_NOSPACE)
+               return WRDE_NOSPACE;
+
+       if ((flags & WRDE_APPEND) == 0)
+               wordfree(we);
+
+       *we = old_word;
+       return error;
+}