--- /dev/null
+/* $NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $ */
+
+/*-
+ * Copyright (c) 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)alias.c 8.3 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: alias.c,v 1.12 2003/08/07 09:05:29 agc Exp $");
+#endif
+#endif /* not lint */
+
+#include <stdlib.h>
+#include "shell.h"
+#include "input.h"
+#include "output.h"
+#include "error.h"
+#include "memalloc.h"
+#include "mystring.h"
+#include "alias.h"
+#include "options.h" /* XXX for argptr (should remove?) */
+#include "var.h"
+
+#define ATABSIZE 39
+
+struct alias *atab[ATABSIZE];
+
+STATIC void setalias(char *, char *);
+STATIC int unalias(char *);
+STATIC struct alias **hashalias(char *);
+
+STATIC
+void
+setalias(char *name, char *val)
+{
+ struct alias *ap, **app;
+
+ app = hashalias(name);
+ for (ap = *app; ap; ap = ap->next) {
+ if (equal(name, ap->name)) {
+ INTOFF;
+ ckfree(ap->val);
+ ap->val = savestr(val);
+ INTON;
+ return;
+ }
+ }
+ /* not found */
+ INTOFF;
+ ap = ckmalloc(sizeof (struct alias));
+ ap->name = savestr(name);
+ /*
+ * XXX - HACK: in order that the parser will not finish reading the
+ * alias value off the input before processing the next alias, we
+ * dummy up an extra space at the end of the alias. This is a crock
+ * and should be re-thought. The idea (if you feel inclined to help)
+ * is to avoid alias recursions. The mechanism used is: when
+ * expanding an alias, the value of the alias is pushed back on the
+ * input as a string and a pointer to the alias is stored with the
+ * string. The alias is marked as being in use. When the input
+ * routine finishes reading the string, it markes the alias not
+ * in use. The problem is synchronization with the parser. Since
+ * it reads ahead, the alias is marked not in use before the
+ * resulting token(s) is next checked for further alias sub. The
+ * H A C K is that we add a little fluff after the alias value
+ * so that the string will not be exhausted. This is a good
+ * idea ------- ***NOT***
+ */
+#ifdef notyet
+ ap->val = savestr(val);
+#else /* hack */
+ {
+ int len = strlen(val);
+ ap->val = ckmalloc(len + 2);
+ memcpy(ap->val, val, len);
+ ap->val[len] = ' '; /* fluff */
+ ap->val[len+1] = '\0';
+ }
+#endif
+ ap->next = *app;
+ *app = ap;
+ INTON;
+}
+
+STATIC int
+unalias(char *name)
+{
+ struct alias *ap, **app;
+
+ app = hashalias(name);
+
+ for (ap = *app; ap; app = &(ap->next), ap = ap->next) {
+ if (equal(name, ap->name)) {
+ /*
+ * if the alias is currently in use (i.e. its
+ * buffer is being used by the input routine) we
+ * just null out the name instead of freeing it.
+ * We could clear it out later, but this situation
+ * is so rare that it hardly seems worth it.
+ */
+ if (ap->flag & ALIASINUSE)
+ *ap->name = '\0';
+ else {
+ INTOFF;
+ *app = ap->next;
+ ckfree(ap->name);
+ ckfree(ap->val);
+ ckfree(ap);
+ INTON;
+ }
+ return (0);
+ }
+ }
+
+ return (1);
+}
+
+#ifdef mkinit
+MKINIT void rmaliases(void);
+
+SHELLPROC {
+ rmaliases();
+}
+#endif
+
+void
+rmaliases(void)
+{
+ struct alias *ap, *tmp;
+ int i;
+
+ INTOFF;
+ for (i = 0; i < ATABSIZE; i++) {
+ ap = atab[i];
+ atab[i] = NULL;
+ while (ap) {
+ ckfree(ap->name);
+ ckfree(ap->val);
+ tmp = ap;
+ ap = ap->next;
+ ckfree(tmp);
+ }
+ }
+ INTON;
+}
+
+struct alias *
+lookupalias(char *name, int check)
+{
+ struct alias *ap = *hashalias(name);
+
+ for (; ap; ap = ap->next) {
+ if (equal(name, ap->name)) {
+ if (check && (ap->flag & ALIASINUSE))
+ return (NULL);
+ return (ap);
+ }
+ }
+
+ return (NULL);
+}
+
+char *
+get_alias_text(char *name)
+{
+ struct alias *ap;
+
+ ap = lookupalias(name, 0);
+ if (ap == NULL)
+ return NULL;
+ return ap->val;
+}
+
+/*
+ * TODO - sort output
+ */
+int
+aliascmd(int argc, char **argv)
+{
+ char *n, *v;
+ int ret = 0;
+ struct alias *ap;
+
+ if (argc == 1) {
+ int i;
+
+ for (i = 0; i < ATABSIZE; i++)
+ for (ap = atab[i]; ap; ap = ap->next) {
+ if (*ap->name != '\0') {
+ out1fmt("alias %s=", ap->name);
+ print_quoted(ap->val);
+ out1c('\n');
+ }
+ }
+ return (0);
+ }
+ while ((n = *++argv) != NULL) {
+ if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */
+ if ((ap = lookupalias(n, 0)) == NULL) {
+ outfmt(out2, "alias: %s not found\n", n);
+ ret = 1;
+ } else {
+ out1fmt("alias %s=", n);
+ print_quoted(ap->val);
+ out1c('\n');
+ }
+ } else {
+ *v++ = '\0';
+ setalias(n, v);
+ }
+ }
+
+ return (ret);
+}
+
+int
+unaliascmd(int argc, char **argv)
+{
+ int i;
+
+ while ((i = nextopt("a")) != '\0') {
+ if (i == 'a') {
+ rmaliases();
+ return (0);
+ }
+ }
+ for (i = 0; *argptr; argptr++)
+ i = unalias(*argptr);
+
+ return (i);
+}
+
+STATIC struct alias **
+hashalias(char *p)
+{
+ unsigned int hashval;
+
+ hashval = *p << 4;
+ while (*p)
+ hashval+= *p++;
+ return &atab[hashval % ATABSIZE];
+}
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