sha3sum: new applet

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

diff --git a/coreutils/head.c b/coreutils/head.c
index 56e7a960cde2e710943a4683643fc2aca4f3e383..ec4512765abff2f2bd5a387b630b4dea92b17351 100644 (file)
--- a/coreutils/head.c
+++ b/coreutils/head.c
@@ -4,33 +4,53 @@
  *
  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
 /* BB_AUDIT SUSv3 compliant */
 /* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
 
-#include "busybox.h"
+//usage:#define head_trivial_usage
+//usage:       "[OPTIONS] [FILE]..."
+//usage:#define head_full_usage "\n\n"
+//usage:       "Print first 10 lines of each FILE (or stdin) to stdout.\n"
+//usage:       "With more than one FILE, precede each with a filename header.\n"
+//usage:     "\n       -n N[kbm]       Print first N lines"
+//usage:       IF_FEATURE_FANCY_HEAD(
+//usage:     "\n       -c N[kbm]       Print first N bytes"
+//usage:     "\n       -q              Never print headers"
+//usage:     "\n       -v              Always print headers"
+//usage:       )
+//usage:     "\n"
+//usage:     "\nN may be suffixed by k (x1024), b (x512), or m (x1024^2)."
+//usage:
+//usage:#define head_example_usage
+//usage:       "$ head -n 2 /etc/passwd\n"
+//usage:       "root:x:0:0:root:/root:/bin/bash\n"
+//usage:       "daemon:x:1:1:daemon:/usr/sbin:/bin/sh\n"
 
-static const char head_opts[] =
+#include "libbb.h"
+
+/* This is a NOEXEC applet. Be very careful! */
+
+static const char head_opts[] ALIGN1 =
        "n:"
 #if ENABLE_FEATURE_FANCY_HEAD
        "c:qv"
 #endif
        ;
 
-#if ENABLE_FEATURE_FANCY_HEAD
 static const struct suffix_mult head_suffixes[] = {
        { "b", 512 },
        { "k", 1024 },
        { "m", 1024*1024 },
-       { NULL, 0 }
+       { "", 0 }
 };
-#endif
 
-static const char header_fmt_str[] = "\n==> %s <==\n";
+#define header_fmt_str "\n==> %s <==\n"
 
+int head_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int head_main(int argc, char **argv)
 {
        unsigned long count = 10;
@@ -39,7 +59,6 @@ int head_main(int argc, char **argv)
        int count_bytes = 0;
        int header_threshhold = 1;
 #endif
-
        FILE *fp;
        const char *fmt;
        char *p;
@@ -49,7 +68,7 @@ int head_main(int argc, char **argv)
 
 #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
        /* Allow legacy syntax of an initial numeric option without -n. */
-       if (argc > 1 && argv[1][0] == '-'
+       if (argv[1] && argv[1][0] == '-'
         && isdigit(argv[1][1])
        ) {
                --argc;
@@ -78,31 +97,26 @@ int head_main(int argc, char **argv)
 #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
  GET_COUNT:
 #endif
-
-#if !ENABLE_FEATURE_FANCY_HEAD
-                       count = xatoul(p);
-#else
                        count = xatoul_sfx(p, head_suffixes);
-#endif
                        break;
                default:
                        bb_show_usage();
                }
        }
 
+       argc -= optind;
        argv += optind;
-       if (!*argv) {
-               *--argv = "-";
-       }
+       if (!*argv)
+               *--argv = (char*)"-";
 
        fmt = header_fmt_str + 1;
 #if ENABLE_FEATURE_FANCY_HEAD
-       if (argc - optind <= header_threshhold) {
+       if (argc <= header_threshhold) {
                header_threshhold = 0;
        }
 #else
-       if (argc <= optind + 1) {
-               fmt += 11;
+       if (argc <= 1) {
+               fmt += 11; /* "" */
        }
        /* Now define some things here to avoid #ifdefs in the code below.
         * These should optimize out of the if conditions below. */
@@ -127,10 +141,12 @@ int head_main(int argc, char **argv)
                                putchar(c);
                        }
                        if (fclose_if_not_stdin(fp)) {
-                               bb_perror_msg("%s", *argv);     /* Avoid multibyte problems. */
+                               bb_simple_perror_msg(*argv);
                                retval = EXIT_FAILURE;
                        }
                        die_if_ferror_stdout();
+               } else {
+                       retval = EXIT_FAILURE;
                }
                fmt = header_fmt_str;
        } while (*++argv);