busybox/editors/cmp.c
Denis Vlasenko 62a90cdd74 *: shrink by using [f]open_or_warn_stdin where appropriate
function                                             old     new   delta
lsattr_main                                           62     143     +81
open_or_warn_stdin                                     -      36     +36
fclose_if_not_stdin                                   20      47     +27
xfopen_stdin                                           -      20     +20
tac_main                                             336     356     +20
cksum_main                                           249     259     +10
bb_argv_dash                                           -       8      +8
su_main                                              448     455      +7
cmp_main                                             630     633      +3
passwd_main                                         1072    1074      +2
uudecode_main                                        317     315      -2
text_yank                                            110     108      -2
handle_incoming_and_exit                            2653    2651      -2
flags                                                  5       1      -4
write_leases                                         235     230      -5
fopen_or_warn_stdin                                   48      42      -6
fold_main                                            648     642      -6
static.argv_dash                                       8       -      -8
sum_main                                             142     128     -14
tail_main                                           1237    1221     -16
sed_main                                             711     695     -16
cmp_xfopen_input                                      17       -     -17
bb_cat                                               113      96     -17
catv_main                                            328     306     -22
strings_main                                         457     434     -23
hash_file                                            298     274     -24
sum_file                                             353     325     -28
sort_main                                            904     859     -45
expand_main                                          736     686     -50
cut_main                                            1116    1065     -51
md5_sha1_sum_main                                    549     493     -56
lsattr_args                                           90       -     -90
read_stduu                                           408     255    -153
------------------------------------------------------------------------------
(add/remove: 3/3 grow/shrink: 7/20 up/down: 214/-657)        Total: -443 bytes
   text    data     bss     dec     hex filename
 797417     658    7428  805503   c4a7f busybox_old
 796973     658    7428  805059   c48c3 busybox_unstripped
2008-03-17 09:07:36 +00:00

136 lines
3.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini cmp implementation for busybox
*
* Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
*
* Original version majorly reworked for SUSv3 compliance, bug fixes, and
* size optimizations. Changes include:
* 1) Now correctly distinguishes between errors and actual file differences.
* 2) Proper handling of '-' args.
* 3) Actual error checking of i/o.
* 4) Accept SUSv3 -l option. Note that we use the slightly nicer gnu format
* in the '-l' case.
*/
#include "libbb.h"
static const char fmt_eof[] ALIGN1 = "cmp: EOF on %s\n";
static const char fmt_differ[] ALIGN1 = "%s %s differ: char %"OFF_FMT"d, line %d\n";
// This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%"OFF_FMT"d %o %o\n"
static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%"OFF_FMT"d %3o %3o\n";
static const char opt_chars[] ALIGN1 = "sl";
#define CMP_OPT_s (1<<0)
#define CMP_OPT_l (1<<1)
int cmp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cmp_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
FILE *fp1, *fp2, *outfile = stdout;
const char *filename1, *filename2 = "-";
USE_DESKTOP(off_t skip1 = 0, skip2 = 0;)
off_t char_pos = 0;
int line_pos = 1; /* Hopefully won't overflow... */
const char *fmt;
int c1, c2;
unsigned opt;
int retval = 0;
xfunc_error_retval = 2; /* 1 is returned if files are different. */
opt_complementary = "-1"
USE_DESKTOP(":?4")
SKIP_DESKTOP(":?2")
":l--s:s--l";
opt = getopt32(argv, opt_chars);
argv += optind;
filename1 = *argv;
fp1 = xfopen_stdin(filename1);
if (*++argv) {
filename2 = *argv;
#if ENABLE_DESKTOP
if (*++argv) {
skip1 = XATOOFF(*argv);
if (*++argv) {
skip2 = XATOOFF(*argv);
}
}
#endif
}
fp2 = xfopen_stdin(filename2);
if (fp1 == fp2) { /* Paranoia check... stdin == stdin? */
/* Note that we don't bother reading stdin. Neither does gnu wc.
* But perhaps we should, so that other apps down the chain don't
* get the input. Consider 'echo hello | (cmp - - && cat -)'.
*/
return 0;
}
if (opt & CMP_OPT_l)
fmt = fmt_l_opt;
else
fmt = fmt_differ;
#if ENABLE_DESKTOP
while (skip1) { getc(fp1); skip1--; }
while (skip2) { getc(fp2); skip2--; }
#endif
do {
c1 = getc(fp1);
c2 = getc(fp2);
++char_pos;
if (c1 != c2) { /* Remember: a read error may have occurred. */
retval = 1; /* But assume the files are different for now. */
if (c2 == EOF) {
/* We know that fp1 isn't at EOF or in an error state. But to
* save space below, things are setup to expect an EOF in fp1
* if an EOF occurred. So, swap things around.
*/
fp1 = fp2;
filename1 = filename2;
c1 = c2;
}
if (c1 == EOF) {
die_if_ferror(fp1, filename1);
fmt = fmt_eof; /* Well, no error, so it must really be EOF. */
outfile = stderr;
/* There may have been output to stdout (option -l), so
* make sure we fflush before writing to stderr. */
xfflush_stdout();
}
if (!(opt & CMP_OPT_s)) {
if (opt & CMP_OPT_l) {
line_pos = c1; /* line_pos is unused in the -l case. */
}
fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
if (opt) { /* This must be -l since not -s. */
/* If we encountered an EOF,
* the while check will catch it. */
continue;
}
}
break;
}
if (c1 == '\n') {
++line_pos;
}
} while (c1 != EOF);
die_if_ferror(fp1, filename1);
die_if_ferror(fp2, filename2);
fflush_stdout_and_exit(retval);
}