lpd: now with "svn add"...

diff --git a/printutils/lpd.c b/printutils/lpd.c
new file mode 100644 (file)
index 0000000..ed3d9d1
--- /dev/null
+++ b/printutils/lpd.c
@@ -0,0 +1,79 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * micro lpd - a small non-queueing lpd
+ *
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+#include "libbb.h"
+
+int lpd_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
+int lpd_main(int argc, char *argv[])
+{
+       char *s;
+
+       // goto spool directory
+       // spool directory contains either links to real printer devices or just simple files
+       // these links or files are called "queues"
+       if (!argv[1])
+               bb_show_usage();
+
+       xchdir(argv[1]);
+
+       xdup2(1, 2);
+
+       // read command
+       s = xmalloc_reads(STDIN_FILENO, NULL);
+
+       // N.B. we keep things simple
+       // only "receive job" command is meaningful here...
+       if (2 == *s) {
+               char *queue;
+
+               // parse command: "\x2QUEUE_NAME\n"
+               queue = s + 1;
+               *strchrnul(s, '\n') = '\0';
+
+               while (1) {
+                       // signal OK
+                       write(STDOUT_FILENO, "", 1);
+                       // get subcommand
+                       s = xmalloc_reads(STDIN_FILENO, NULL);
+                       if (!s)
+                               return EXIT_SUCCESS; // EOF (probably)
+                       // valid s must be of form: SUBCMD | LEN | SP | FNAME
+                       // N.B. we bail out on any error
+                       // control or data file follows
+                       if (2 == s[0] || 3 == s[0]) {
+                               int fd;
+                               size_t len;
+                               // 2: control file (ignoring), 3: data file
+                               fd = -1;
+                               if (3 == s[0])
+                                       fd = xopen(queue, O_RDWR | O_APPEND);
+                               // get data length
+                               *strchrnul(s, ' ') = '\0';
+                               len = xatou(s + 1);
+                               // dump exactly len bytes to file, or die
+                               bb_copyfd_exact_size(STDIN_FILENO, fd, len);
+                               close(fd); // NB: can do close(-1). Who cares?
+                               free(s);
+                               // got no ACK? -> bail out
+                               if (safe_read(STDIN_FILENO, s, 1) <= 0 || s[0]) {
+                                       // don't talk to peer - it obviously
+                                       // don't follow the protocol
+                                       return EXIT_FAILURE;
+                               }
+                       } else {
+                               // any other subcommand aborts receiving job
+                               // N.B. abort subcommand itself doesn't contain
+                               // fname so it failed earlier...
+                               break;
+                       }
+               }
+       }
+
+       printf("Command %02x not supported\n", (unsigned char)*s);
+       return EXIT_FAILURE;
+}