Contents of /trunk/mkinitrd-magellan/busybox/editors/cmp.c
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Wed Aug 18 21:56:57 2010 UTC (14 years, 1 month ago) by niro
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Wed Aug 18 21:56:57 2010 UTC (14 years, 1 month ago) by niro
File MIME type: text/plain
File size: 3324 byte(s)
-updated to busybox-1.17.1
1 | /* 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 | #include "libbb.h" |
14 | |
15 | static const char fmt_eof[] ALIGN1 = "cmp: EOF on %s\n"; |
16 | static const char fmt_differ[] ALIGN1 = "%s %s differ: char %"OFF_FMT"u, line %u\n"; |
17 | // This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%"OFF_FMT"u %o %o\n" |
18 | static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%"OFF_FMT"u %3o %3o\n"; |
19 | |
20 | static const char opt_chars[] ALIGN1 = "sl"; |
21 | #define CMP_OPT_s (1<<0) |
22 | #define CMP_OPT_l (1<<1) |
23 | |
24 | int cmp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
25 | int cmp_main(int argc UNUSED_PARAM, char **argv) |
26 | { |
27 | FILE *fp1, *fp2, *outfile = stdout; |
28 | const char *filename1, *filename2 = "-"; |
29 | off_t skip1 = 0, skip2 = 0, char_pos = 0; |
30 | int line_pos = 1; /* Hopefully won't overflow... */ |
31 | const char *fmt; |
32 | int c1, c2; |
33 | unsigned opt; |
34 | int retval = 0; |
35 | |
36 | xfunc_error_retval = 2; /* 1 is returned if files are different. */ |
37 | |
38 | opt_complementary = "-1" |
39 | IF_DESKTOP(":?4") |
40 | IF_NOT_DESKTOP(":?2") |
41 | ":l--s:s--l"; |
42 | opt = getopt32(argv, opt_chars); |
43 | argv += optind; |
44 | |
45 | filename1 = *argv; |
46 | fp1 = xfopen_stdin(filename1); |
47 | |
48 | if (*++argv) { |
49 | filename2 = *argv; |
50 | if (ENABLE_DESKTOP && *++argv) { |
51 | skip1 = XATOOFF(*argv); |
52 | if (*++argv) { |
53 | skip2 = XATOOFF(*argv); |
54 | } |
55 | } |
56 | } |
57 | |
58 | fp2 = xfopen_stdin(filename2); |
59 | if (fp1 == fp2) { /* Paranoia check... stdin == stdin? */ |
60 | /* Note that we don't bother reading stdin. Neither does gnu wc. |
61 | * But perhaps we should, so that other apps down the chain don't |
62 | * get the input. Consider 'echo hello | (cmp - - && cat -)'. |
63 | */ |
64 | return 0; |
65 | } |
66 | |
67 | if (opt & CMP_OPT_l) |
68 | fmt = fmt_l_opt; |
69 | else |
70 | fmt = fmt_differ; |
71 | |
72 | if (ENABLE_DESKTOP) { |
73 | while (skip1) { getc(fp1); skip1--; } |
74 | while (skip2) { getc(fp2); skip2--; } |
75 | } |
76 | do { |
77 | c1 = getc(fp1); |
78 | c2 = getc(fp2); |
79 | ++char_pos; |
80 | if (c1 != c2) { /* Remember: a read error may have occurred. */ |
81 | retval = 1; /* But assume the files are different for now. */ |
82 | if (c2 == EOF) { |
83 | /* We know that fp1 isn't at EOF or in an error state. But to |
84 | * save space below, things are setup to expect an EOF in fp1 |
85 | * if an EOF occurred. So, swap things around. |
86 | */ |
87 | fp1 = fp2; |
88 | filename1 = filename2; |
89 | c1 = c2; |
90 | } |
91 | if (c1 == EOF) { |
92 | die_if_ferror(fp1, filename1); |
93 | fmt = fmt_eof; /* Well, no error, so it must really be EOF. */ |
94 | outfile = stderr; |
95 | /* There may have been output to stdout (option -l), so |
96 | * make sure we fflush before writing to stderr. */ |
97 | fflush_all(); |
98 | } |
99 | if (!(opt & CMP_OPT_s)) { |
100 | if (opt & CMP_OPT_l) { |
101 | line_pos = c1; /* line_pos is unused in the -l case. */ |
102 | } |
103 | fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2); |
104 | if (opt) { /* This must be -l since not -s. */ |
105 | /* If we encountered an EOF, |
106 | * the while check will catch it. */ |
107 | continue; |
108 | } |
109 | } |
110 | break; |
111 | } |
112 | if (c1 == '\n') { |
113 | ++line_pos; |
114 | } |
115 | } while (c1 != EOF); |
116 | |
117 | die_if_ferror(fp1, filename1); |
118 | die_if_ferror(fp2, filename2); |
119 | |
120 | fflush_stdout_and_exit(retval); |
121 | } |