1 /* vi: set sw=4 ts=4: */
3 * Mini cmp implementation for busybox
5 * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 /* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
13 //usage:#define cmp_trivial_usage
14 //usage: "[-l] [-s] FILE1 [FILE2" IF_DESKTOP(" [SKIP1 [SKIP2]]") "]"
15 //usage:#define cmp_full_usage "\n\n"
16 //usage: "Compare FILE1 with FILE2 (or stdin)\n"
17 //usage: "\n -l Write the byte numbers (decimal) and values (octal)"
18 //usage: "\n for all differing bytes"
19 //usage: "\n -s Quiet"
23 static const char fmt_eof
[] ALIGN1
= "cmp: EOF on %s\n";
24 static const char fmt_differ
[] ALIGN1
= "%s %s differ: char %"OFF_FMT
"u, line %u\n";
25 // This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%"OFF_FMT"u %o %o\n"
26 static const char fmt_l_opt
[] ALIGN1
= "%.0s%.0s%"OFF_FMT
"u %3o %3o\n";
28 static const char opt_chars
[] ALIGN1
= "sl";
29 #define CMP_OPT_s (1<<0)
30 #define CMP_OPT_l (1<<1)
32 int cmp_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
33 int cmp_main(int argc UNUSED_PARAM
, char **argv
)
35 FILE *fp1
, *fp2
, *outfile
= stdout
;
36 const char *filename1
, *filename2
= "-";
37 off_t skip1
= 0, skip2
= 0, char_pos
= 0;
38 int line_pos
= 1; /* Hopefully won't overflow... */
44 opt_complementary
= "-1"
48 opt
= getopt32(argv
, opt_chars
);
54 if (ENABLE_DESKTOP
&& *++argv
) {
55 skip1
= XATOOFF(*argv
);
57 skip2
= XATOOFF(*argv
);
62 xfunc_error_retval
= 2; /* missing file results in exitcode 2 */
64 logmode
= 0; /* -s suppresses open error messages */
65 fp1
= xfopen_stdin(filename1
);
66 fp2
= xfopen_stdin(filename2
);
67 if (fp1
== fp2
) { /* Paranoia check... stdin == stdin? */
68 /* Note that we don't bother reading stdin. Neither does gnu wc.
69 * But perhaps we should, so that other apps down the chain don't
70 * get the input. Consider 'echo hello | (cmp - - && cat -)'.
74 logmode
= LOGMODE_STDIO
;
82 while (skip1
) { getc(fp1
); skip1
--; }
83 while (skip2
) { getc(fp2
); skip2
--; }
89 if (c1
!= c2
) { /* Remember: a read error may have occurred. */
90 retval
= 1; /* But assume the files are different for now. */
92 /* We know that fp1 isn't at EOF or in an error state. But to
93 * save space below, things are setup to expect an EOF in fp1
94 * if an EOF occurred. So, swap things around.
97 filename1
= filename2
;
101 die_if_ferror(fp1
, filename1
);
102 fmt
= fmt_eof
; /* Well, no error, so it must really be EOF. */
104 /* There may have been output to stdout (option -l), so
105 * make sure we fflush before writing to stderr. */
108 if (!(opt
& CMP_OPT_s
)) {
109 if (opt
& CMP_OPT_l
) {
110 line_pos
= c1
; /* line_pos is unused in the -l case. */
112 fprintf(outfile
, fmt
, filename1
, filename2
, char_pos
, line_pos
, c2
);
113 if (opt
) { /* This must be -l since not -s. */
114 /* If we encountered an EOF,
115 * the while check will catch it. */
126 die_if_ferror(fp1
, filename1
);
127 die_if_ferror(fp2
, filename2
);
129 fflush_stdout_and_exit(retval
);