randomconfig fixes

[oweals/busybox.git] / coreutils / tac.c

diff --git a/coreutils/tac.c b/coreutils/tac.c
index b1b47302f8e912ca48a03d3d5e2a65a10f5a99de..25e85f6f33c5cd45860045a0bf0247bcaa9977f8 100644 (file)
--- a/coreutils/tac.c
+++ b/coreutils/tac.c
@@ -1,35 +1,65 @@
 /* vi: set sw=4 ts=4: */
 /*
  * tac implementation for busybox
+ * tac - concatenate and print files in reverse
  *
  * 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.
- *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
-
-/* 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
  */
+//config:config TAC
+//config:      bool "tac (3.9 kb)"
+//config:      default y
+//config:      help
+//config:      tac is used to concatenate and print files in reverse.
+
+//applet:IF_TAC(APPLET_NOEXEC(tac, tac, BB_DIR_USR_BIN, BB_SUID_DROP, tac))
+
+//kbuild:lib-$(CONFIG_TAC) += tac.o
+
+//usage:#define tac_trivial_usage
+//usage:       "[FILE]..."
+//usage:#define tac_full_usage "\n\n"
+//usage:       "Concatenate FILEs and print them in reverse"
 
 #include "libbb.h"
 
 /* This is a NOEXEC applet. Be very careful! */
 
+struct lstring {
+       int size;
+       char buf[1];
+};
+
 int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int tac_main(int argc, char **argv)
+int tac_main(int argc UNUSED_PARAM, char **argv)
 {
        char **name;
        FILE *f;
-       char *line;
+       struct lstring *line = NULL;
        llist_t *list = NULL;
        int retval = EXIT_SUCCESS;
 
+#if ENABLE_DESKTOP
+/* tac from coreutils 6.9 supports:
+       -b, --before
+              attach the separator before instead of after
+       -r, --regex
+              interpret the separator as a regular expression
+       -s, --separator=STRING
+              use STRING as the separator instead of newline
+We support none, but at least we will complain or handle "--":
+*/
+       getopt32(argv, "");
+       argv += optind;
+#else
        argv++;
+#endif
        if (!*argv)
                *--argv = (char *)"-";
        /* We will read from last file to first */
@@ -38,21 +68,35 @@ int tac_main(int argc, char **argv)
                name++;
 
        do {
+               int ch, i;
+
                name--;
                f = fopen_or_warn_stdin(*name);
                if (f == NULL) {
+                       /* error message is printed by fopen_or_warn_stdin */
                        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. */
+               errno = i = 0;
+               do {
+                       ch = fgetc(f);
+                       if (ch != EOF) {
+                               if (!(i & 0x7f))
+                                       /* Grow on every 128th char */
+                                       line = xrealloc(line, i + 0x7f + sizeof(int) + 1);
+                               line->buf[i++] = ch;
+                       }
+                       if (ch == '\n' || (ch == EOF && i != 0)) {
+                               line = xrealloc(line, i + sizeof(int));
+                               line->size = i;
+                               llist_add_to(&list, line);
+                               line = NULL;
+                               i = 0;
+                       }
+               } while (ch != EOF);
+               /* fgetc sets errno to ENOENT on EOF, we don't want
+                * to warn on this non-error! */
                if (errno && errno != ENOENT) {
                        bb_simple_perror_msg(*name);
                        retval = EXIT_FAILURE;
@@ -60,8 +104,13 @@ int tac_main(int argc, char **argv)
        } while (name != argv);
 
        while (list) {
-               printf("%s", list->data);
-               list = list->link;
+               line = (struct lstring *)list->data;
+               xwrite(STDOUT_FILENO, line->buf, line->size);
+               if (ENABLE_FEATURE_CLEAN_UP) {
+                       free(llist_pop(&list));
+               } else {
+                       list = list->link;
+               }
        }
 
        return retval;