ntpd: default to FEATURE_NTP_AUTH=y

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

diff --git a/coreutils/tac.c b/coreutils/tac.c
index ddadcc7bc6d2368c08de47be42a8753ab1fc8596..6d3ea9c199d5cb9472592c297037f113bda78951 100644 (file)
--- a/coreutils/tac.c
+++ b/coreutils/tac.c
@@ -1,20 +1,31 @@
 /* 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 (4.1 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"
 
@@ -22,11 +33,11 @@
 
 struct lstring {
        int size;
-       char buf[];
+       char buf[1];
 };
 
 int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
+int tac_main(int argc UNUSED_PARAM, char **argv)
 {
        char **name;
        FILE *f;
@@ -34,7 +45,21 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
        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 */
@@ -48,6 +73,7 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
                name--;
                f = fopen_or_warn_stdin(*name);
                if (f == NULL) {
+                       /* error message is printed by fopen_or_warn_stdin */
                        retval = EXIT_FAILURE;
                        continue;
                }
@@ -61,7 +87,7 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                        line = xrealloc(line, i + 0x7f + sizeof(int) + 1);
                                line->buf[i++] = ch;
                        }
-                       if ((ch == '\n' || ch == EOF) && i) {
+                       if (ch == '\n' || (ch == EOF && i != 0)) {
                                line = xrealloc(line, i + sizeof(int));
                                line->size = i;
                                llist_add_to(&list, line);
@@ -69,9 +95,8 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                i = 0;
                        }
                } while (ch != EOF);
-               /* fgetc sets errno to ENOENT on EOF, but     */
-               /* fopen_or_warn_stdin would catch this error */
-               /* so we can filter it out here.              */
+               /* 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;