tac: *really* add tac.c now

diff --git a/coreutils/tac.c b/coreutils/tac.c
new file mode 100644 (file)
index 0000000..6aa0528
--- /dev/null
+++ b/coreutils/tac.c
@@ -0,0 +1,68 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * tac implementation for busybox
+ *
+ * Copyright (C) 2003  Yang Xiaopeng  <yxp at hanwang.com.cn>
+ * Copyright (C) 2007  Natanael Copa  <natanael.copa@gmail.com>
+ * Copyright (C) 2007  Tito Ragusa    <farmatito@tiscali.it>
+ *
+ * Licensed under GPLv2, see file License in this tarball for details.
+ *
+ */
+
+/* tac - concatenate and print files in reverse */
+
+/* Based on Yang Xiaopeng's (yxp at hanwang.com.cn) patch
+ * http://www.uclibc.org/lists/busybox/2003-July/008813.html
+ */
+
+#include "libbb.h"
+
+/* This is a NOEXEC applet. Be very careful! */
+
+int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int tac_main(int argc, char **argv)
+{
+       char **name;
+       FILE *f;
+       char *line;
+       llist_t *list = NULL;
+       int retval = EXIT_SUCCESS;
+       
+       argv++;
+       if (!*argv)
+               *--argv = (char *)"-";
+       /* We will read from last file to first */
+       name = argv;
+       while (*name)
+               name++;
+
+       do {
+               name--;
+               f = fopen_or_warn_stdin(*name);
+               if (f == NULL) {
+                       retval = EXIT_FAILURE;
+                       continue;
+               }
+
+               errno = 0;
+               /* FIXME: NUL bytes are mishandled. */
+               while ((line = xmalloc_fgets(f)) != NULL)
+                       llist_add_to(&list, line);      
+
+               /* xmalloc_fgets uses getc and returns NULL on error or EOF. */
+               /* It sets errno to ENOENT on EOF, but fopen_or_warn_stdin would */
+               /* catch this error so we can filter it out here. */
+               if (errno && errno != ENOENT) {
+                       bb_simple_perror_msg(*name);
+                       retval = EXIT_FAILURE;
+               }
+       } while (name != argv);
+
+       while (list) {
+               printf("%s", list->data);
+               list = list->link;
+       }
+       
+       return retval;
+}