Annotation of /trunk/mkinitrd-magellan/busybox/editors/cmp.c
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Revision 816 -
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Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
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File size: 3787 byte(s)
Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 3787 byte(s)
-updated to busybox-1.13.4
1 | niro | 816 | /* vi: set sw=4 ts=4: */ |
2 | /* | ||
3 | * Mini cmp implementation for busybox | ||
4 | * | ||
5 | * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu> | ||
6 | * | ||
7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | ||
8 | */ | ||
9 | |||
10 | /* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */ | ||
11 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */ | ||
12 | |||
13 | /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) | ||
14 | * | ||
15 | * Original version majorly reworked for SUSv3 compliance, bug fixes, and | ||
16 | * size optimizations. Changes include: | ||
17 | * 1) Now correctly distinguishes between errors and actual file differences. | ||
18 | * 2) Proper handling of '-' args. | ||
19 | * 3) Actual error checking of i/o. | ||
20 | * 4) Accept SUSv3 -l option. Note that we use the slightly nicer gnu format | ||
21 | * in the '-l' case. | ||
22 | */ | ||
23 | |||
24 | #include "libbb.h" | ||
25 | |||
26 | static const char fmt_eof[] ALIGN1 = "cmp: EOF on %s\n"; | ||
27 | static const char fmt_differ[] ALIGN1 = "%s %s differ: char %"OFF_FMT"d, line %d\n"; | ||
28 | // This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%"OFF_FMT"d %o %o\n" | ||
29 | static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%"OFF_FMT"d %3o %3o\n"; | ||
30 | |||
31 | static const char opt_chars[] ALIGN1 = "sl"; | ||
32 | #define CMP_OPT_s (1<<0) | ||
33 | #define CMP_OPT_l (1<<1) | ||
34 | |||
35 | int cmp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; | ||
36 | int cmp_main(int argc UNUSED_PARAM, char **argv) | ||
37 | { | ||
38 | FILE *fp1, *fp2, *outfile = stdout; | ||
39 | const char *filename1, *filename2 = "-"; | ||
40 | USE_DESKTOP(off_t skip1 = 0, skip2 = 0;) | ||
41 | off_t char_pos = 0; | ||
42 | int line_pos = 1; /* Hopefully won't overflow... */ | ||
43 | const char *fmt; | ||
44 | int c1, c2; | ||
45 | unsigned opt; | ||
46 | int retval = 0; | ||
47 | |||
48 | xfunc_error_retval = 2; /* 1 is returned if files are different. */ | ||
49 | |||
50 | opt_complementary = "-1" | ||
51 | USE_DESKTOP(":?4") | ||
52 | SKIP_DESKTOP(":?2") | ||
53 | ":l--s:s--l"; | ||
54 | opt = getopt32(argv, opt_chars); | ||
55 | argv += optind; | ||
56 | |||
57 | filename1 = *argv; | ||
58 | fp1 = xfopen_stdin(filename1); | ||
59 | |||
60 | if (*++argv) { | ||
61 | filename2 = *argv; | ||
62 | #if ENABLE_DESKTOP | ||
63 | if (*++argv) { | ||
64 | skip1 = XATOOFF(*argv); | ||
65 | if (*++argv) { | ||
66 | skip2 = XATOOFF(*argv); | ||
67 | } | ||
68 | } | ||
69 | #endif | ||
70 | } | ||
71 | |||
72 | fp2 = xfopen_stdin(filename2); | ||
73 | if (fp1 == fp2) { /* Paranoia check... stdin == stdin? */ | ||
74 | /* Note that we don't bother reading stdin. Neither does gnu wc. | ||
75 | * But perhaps we should, so that other apps down the chain don't | ||
76 | * get the input. Consider 'echo hello | (cmp - - && cat -)'. | ||
77 | */ | ||
78 | return 0; | ||
79 | } | ||
80 | |||
81 | if (opt & CMP_OPT_l) | ||
82 | fmt = fmt_l_opt; | ||
83 | else | ||
84 | fmt = fmt_differ; | ||
85 | |||
86 | #if ENABLE_DESKTOP | ||
87 | while (skip1) { getc(fp1); skip1--; } | ||
88 | while (skip2) { getc(fp2); skip2--; } | ||
89 | #endif | ||
90 | do { | ||
91 | c1 = getc(fp1); | ||
92 | c2 = getc(fp2); | ||
93 | ++char_pos; | ||
94 | if (c1 != c2) { /* Remember: a read error may have occurred. */ | ||
95 | retval = 1; /* But assume the files are different for now. */ | ||
96 | if (c2 == EOF) { | ||
97 | /* We know that fp1 isn't at EOF or in an error state. But to | ||
98 | * save space below, things are setup to expect an EOF in fp1 | ||
99 | * if an EOF occurred. So, swap things around. | ||
100 | */ | ||
101 | fp1 = fp2; | ||
102 | filename1 = filename2; | ||
103 | c1 = c2; | ||
104 | } | ||
105 | if (c1 == EOF) { | ||
106 | die_if_ferror(fp1, filename1); | ||
107 | fmt = fmt_eof; /* Well, no error, so it must really be EOF. */ | ||
108 | outfile = stderr; | ||
109 | /* There may have been output to stdout (option -l), so | ||
110 | * make sure we fflush before writing to stderr. */ | ||
111 | xfflush_stdout(); | ||
112 | } | ||
113 | if (!(opt & CMP_OPT_s)) { | ||
114 | if (opt & CMP_OPT_l) { | ||
115 | line_pos = c1; /* line_pos is unused in the -l case. */ | ||
116 | } | ||
117 | fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2); | ||
118 | if (opt) { /* This must be -l since not -s. */ | ||
119 | /* If we encountered an EOF, | ||
120 | * the while check will catch it. */ | ||
121 | continue; | ||
122 | } | ||
123 | } | ||
124 | break; | ||
125 | } | ||
126 | if (c1 == '\n') { | ||
127 | ++line_pos; | ||
128 | } | ||
129 | } while (c1 != EOF); | ||
130 | |||
131 | die_if_ferror(fp1, filename1); | ||
132 | die_if_ferror(fp2, filename2); | ||
133 | |||
134 | fflush_stdout_and_exit(retval); | ||
135 | } |