Annotation of /tags/mkinitrd-6_3_1/busybox/coreutils/head.c
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Revision 532 -
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Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
Original Path: trunk/mkinitrd-magellan/busybox/coreutils/head.c
File MIME type: text/plain
File size: 2789 byte(s)
Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
Original Path: trunk/mkinitrd-magellan/busybox/coreutils/head.c
File MIME type: text/plain
File size: 2789 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
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 | #include "busybox.h" | ||
15 | |||
16 | static const char head_opts[] = | ||
17 | "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 | { NULL, 0 } | ||
29 | }; | ||
30 | #endif | ||
31 | |||
32 | static const char header_fmt_str[] = "\n==> %s <==\n"; | ||
33 | |||
34 | int head_main(int argc, char **argv) | ||
35 | { | ||
36 | unsigned long count = 10; | ||
37 | unsigned long i; | ||
38 | #if ENABLE_FEATURE_FANCY_HEAD | ||
39 | int count_bytes = 0; | ||
40 | int header_threshhold = 1; | ||
41 | #endif | ||
42 | |||
43 | FILE *fp; | ||
44 | const char *fmt; | ||
45 | char *p; | ||
46 | int opt; | ||
47 | int c; | ||
48 | int retval = EXIT_SUCCESS; | ||
49 | |||
50 | #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD | ||
51 | /* Allow legacy syntax of an initial numeric option without -n. */ | ||
52 | if (argc > 1 && argv[1][0] == '-' | ||
53 | && isdigit(argv[1][1]) | ||
54 | ) { | ||
55 | --argc; | ||
56 | ++argv; | ||
57 | p = (*argv) + 1; | ||
58 | goto GET_COUNT; | ||
59 | } | ||
60 | #endif | ||
61 | |||
62 | /* No size benefit in converting this to getopt32 */ | ||
63 | while ((opt = getopt(argc, argv, head_opts)) > 0) { | ||
64 | switch (opt) { | ||
65 | #if ENABLE_FEATURE_FANCY_HEAD | ||
66 | case 'q': | ||
67 | header_threshhold = INT_MAX; | ||
68 | break; | ||
69 | case 'v': | ||
70 | header_threshhold = -1; | ||
71 | break; | ||
72 | case 'c': | ||
73 | count_bytes = 1; | ||
74 | /* fall through */ | ||
75 | #endif | ||
76 | case 'n': | ||
77 | p = optarg; | ||
78 | #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_HEAD | ||
79 | GET_COUNT: | ||
80 | #endif | ||
81 | |||
82 | #if !ENABLE_FEATURE_FANCY_HEAD | ||
83 | count = xatoul(p); | ||
84 | #else | ||
85 | count = xatoul_sfx(p, head_suffixes); | ||
86 | #endif | ||
87 | break; | ||
88 | default: | ||
89 | bb_show_usage(); | ||
90 | } | ||
91 | } | ||
92 | |||
93 | argv += optind; | ||
94 | if (!*argv) { | ||
95 | *--argv = "-"; | ||
96 | } | ||
97 | |||
98 | fmt = header_fmt_str + 1; | ||
99 | #if ENABLE_FEATURE_FANCY_HEAD | ||
100 | if (argc - optind <= header_threshhold) { | ||
101 | header_threshhold = 0; | ||
102 | } | ||
103 | #else | ||
104 | if (argc <= optind + 1) { | ||
105 | fmt += 11; | ||
106 | } | ||
107 | /* Now define some things here to avoid #ifdefs in the code below. | ||
108 | * These should optimize out of the if conditions below. */ | ||
109 | #define header_threshhold 1 | ||
110 | #define count_bytes 0 | ||
111 | #endif | ||
112 | |||
113 | do { | ||
114 | fp = fopen_or_warn_stdin(*argv); | ||
115 | if (fp) { | ||
116 | if (fp == stdin) { | ||
117 | *argv = (char *) bb_msg_standard_input; | ||
118 | } | ||
119 | if (header_threshhold) { | ||
120 | printf(fmt, *argv); | ||
121 | } | ||
122 | i = count; | ||
123 | while (i && ((c = getc(fp)) != EOF)) { | ||
124 | if (count_bytes || (c == '\n')) { | ||
125 | --i; | ||
126 | } | ||
127 | putchar(c); | ||
128 | } | ||
129 | if (fclose_if_not_stdin(fp)) { | ||
130 | bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */ | ||
131 | retval = EXIT_FAILURE; | ||
132 | } | ||
133 | die_if_ferror_stdout(); | ||
134 | } | ||
135 | fmt = header_fmt_str; | ||
136 | } while (*++argv); | ||
137 | |||
138 | fflush_stdout_and_exit(retval); | ||
139 | } |