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    Annotation of /trunk/mkinitrd-magellan/busybox/coreutils/head.c

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    Revision 816 - (hide annotations) (download)
    Fri Apr 24 18:33:46 2009 UTC (15 years ago) by niro
    File MIME type: text/plain
    File size: 2866 byte(s) 
    -updated to busybox-1.13.4
    1 niro 532 /* vi: set sw=4 ts=4: */
    2     /*
    3     * head implementation for busybox
    4     *
    5     * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
    6     *
    7     * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
    8     */
    9    
    10     /* BB_AUDIT SUSv3 compliant */
    11     /* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
    12     /* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
    13    
    14 niro 816 #include "libbb.h"
    15 niro 532
    16 niro 816 static const char head_opts[] ALIGN1 =
    17 niro 532 "n:"
    18     #if ENABLE_FEATURE_FANCY_HEAD
    19     "c:qv"
    20     #endif
    21     ;
    22    
    23     #if ENABLE_FEATURE_FANCY_HEAD
    24     static const struct suffix_mult head_suffixes[] = {
    25     { "b", 512 },
    26     { "k", 1024 },
    27     { "m", 1024*1024 },
    28 niro 816 { }
    29 niro 532 };
    30     #endif
    31    
    32 niro 816 static const char header_fmt_str[] ALIGN1 = "\n==> %s <==\n";
    33 niro 532
    34 niro 816 int head_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
    35 niro 532 int head_main(int argc, char **argv)
    36     {
    37     unsigned long count = 10;
    38     unsigned long i;
    39     #if ENABLE_FEATURE_FANCY_HEAD
    40     int count_bytes = 0;
    41     int header_threshhold = 1;
    42     #endif
    43    
    44     FILE *fp;
    45     const char *fmt;
    46     char *p;
    47     int opt;
    48     int c;
    49     int retval = EXIT_SUCCESS;
    50    
    51     #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
    52     /* Allow legacy syntax of an initial numeric option without -n. */
    53     if (argc > 1 && argv[1][0] == '-'
    54     && isdigit(argv[1][1])
    55     ) {
    56     --argc;
    57     ++argv;
    58     p = (*argv) + 1;
    59     goto GET_COUNT;
    60     }
    61     #endif
    62    
    63     /* No size benefit in converting this to getopt32 */
    64     while ((opt = getopt(argc, argv, head_opts)) > 0) {
    65     switch (opt) {
    66     #if ENABLE_FEATURE_FANCY_HEAD
    67     case 'q':
    68     header_threshhold = INT_MAX;
    69     break;
    70     case 'v':
    71     header_threshhold = -1;
    72     break;
    73     case 'c':
    74     count_bytes = 1;
    75     /* fall through */
    76     #endif
    77     case 'n':
    78     p = optarg;
    79     #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD
    80     GET_COUNT:
    81     #endif
    82    
    83     #if !ENABLE_FEATURE_FANCY_HEAD
    84     count = xatoul(p);
    85     #else
    86     count = xatoul_sfx(p, head_suffixes);
    87     #endif
    88     break;
    89     default:
    90     bb_show_usage();
    91     }
    92     }
    93    
    94 niro 816 argc -= optind;
    95 niro 532 argv += optind;
    96 niro 816 if (!*argv)
    97     *--argv = (char*)"-";
    98 niro 532
    99     fmt = header_fmt_str + 1;
    100     #if ENABLE_FEATURE_FANCY_HEAD
    101 niro 816 if (argc <= header_threshhold) {
    102 niro 532 header_threshhold = 0;
    103     }
    104     #else
    105 niro 816 if (argc <= 1) {
    106     fmt += 11; /* "" */
    107 niro 532 }
    108     /* Now define some things here to avoid #ifdefs in the code below.
    109     * These should optimize out of the if conditions below. */
    110     #define header_threshhold 1
    111     #define count_bytes 0
    112     #endif
    113    
    114     do {
    115     fp = fopen_or_warn_stdin(*argv);
    116     if (fp) {
    117     if (fp == stdin) {
    118     *argv = (char *) bb_msg_standard_input;
    119     }
    120     if (header_threshhold) {
    121     printf(fmt, *argv);
    122     }
    123     i = count;
    124     while (i && ((c = getc(fp)) != EOF)) {
    125     if (count_bytes || (c == '\n')) {
    126     --i;
    127     }
    128     putchar(c);
    129     }
    130     if (fclose_if_not_stdin(fp)) {
    131 niro 816 bb_simple_perror_msg(*argv); /* Avoid multibyte problems. */
    132 niro 532 retval = EXIT_FAILURE;
    133     }
    134     die_if_ferror_stdout();
    135     }
    136     fmt = header_fmt_str;
    137     } while (*++argv);
    138    
    139     fflush_stdout_and_exit(retval);
    140     }