NetBSD/usr.bin/cmp/cmp.c

286 lines
6.6 KiB
C

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1987, 1990 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "from: @(#)cmp.c 5.3 (Berkeley) 6/1/90";*/
static char rcsid[] = "$Id: cmp.c,v 1.6 1994/03/25 17:07:02 mycroft Exp $";
#endif /* not lint */
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <locale.h>
#include <unistd.h>
#define EXITNODIFF 0
#define EXITDIFF 1
#define EXITERR 2
void skip __P(());
__dead void cmp __P(());
__dead void error __P(());
__dead void endoffile __P(());
__dead void usage __P(());
int all, fd1, fd2, silent;
u_char buffer1[MAXBSIZE], buffer2[MAXBSIZE];
char *file1, *file2;
int
main(argc, argv)
int argc;
char **argv;
{
int ch;
setlocale(LC_ALL, "");
while ((ch = getopt(argc, argv, "ls")) != -1)
switch (ch) {
case 'l': /* print all differences */
all = 1;
break;
case 's': /* silent run */
silent = 1;
break;
case '?':
default:
usage();
}
argv += optind;
argc -= optind;
if (argc < 2 || argc > 4)
usage();
if (all && silent)
usage ();
if (strcmp(file1 = argv[0], "-") == 0)
fd1 = 0;
else if ((fd1 = open(file1, O_RDONLY, 0)) < 0)
error(file1);
if (strcmp(file2 = argv[1], "-") == 0)
fd2 = 0;
else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
error(file2);
if (fd1 == fd2) {
fprintf(stderr,
"cmp: standard input may only be specified once.\n");
exit(EXITERR);
}
/* handle skip arguments */
if (argc > 2) {
skip(strtoul(argv[2], NULL, 0), fd1, file1);
if (argc == 4)
skip(strtoul(argv[3], NULL, 0), fd2, file2);
}
cmp();
/*NOTREACHED*/
}
/*
* skip --
* skip first part of file
*/
void
skip(dist, fd, fname)
register u_long dist;
register int fd;
char *fname;
{
register int rlen, nread;
for (; dist; dist -= rlen) {
rlen = MIN(dist, sizeof(buffer1));
if ((nread = read(fd, buffer1, rlen)) != rlen) {
if (nread < 0)
error(fname);
else
endoffile(fname);
}
}
}
void
cmp()
{
register u_char *p1, *p2;
u_char *buf1, *buf2;
register int cnt;
int len = 0, len1 = 0, len2 = 0;
register long byte, line;
int dfound = 0;
for (byte = 0, line = 1; ; ) {
len1 -= len;
len2 -= len;
if (len1)
buf1 += len;
else
switch (len1 = read(fd1, buf1 = buffer1, MAXBSIZE)) {
case -1:
error(file1);
case 0:
if (len2)
endoffile(file1);
/*
* read of file 1 just failed, find out
* if there's anything left in file 2
*/
switch (read(fd2, buf2 = buffer2, 1)) {
case -1:
error(file2);
/* NOTREACHED */
case 0:
exit(dfound ? EXITDIFF : EXITNODIFF);
/* NOTREACHED */
default:
endoffile(file1);
break;
}
}
if (len2)
buf2 += len;
else
switch (len2 = read(fd2, buf2 = buffer2, MAXBSIZE)) {
case -1:
error(file2);
case 0:
/*
* read of file 2 just failed; we know there is
* data left in file 1 if we got this far
*/
endoffile(file2);
break;
}
/*
* Either file might be stdio. We compare only the minimum
* number of bytes we know are common, then loop back to the
* top. This avoids blocking on input if a difference is
* found early.
*/
if (len1 < len2)
len = len1;
else
len = len2;
if (memcmp(buf1, buf2, len)) {
if (silent)
exit(EXITDIFF);
if (all) {
dfound = 1;
for (p1 = buf1, p2 = buf2, cnt = len; cnt--;
++p1, ++p2) {
++byte;
if (*p1 != *p2)
printf("%6ld %3o %3o\n",
byte, *p1, *p2);
}
} else for (p1 = buf1, p2 = buf2; ; ++p1, ++p2) {
++byte;
if (*p1 != *p2) {
printf("%s %s differ: char %ld, line %ld\n", file1, file2, byte, line);
exit(EXITDIFF);
}
if (*p1 == '\n')
++line;
}
} else {
byte += len;
/*
* here's the real performance problem, we've got to
* count the stupid lines, which means that -l is a
* *much* faster version, i.e., unless you really
* *want* to know the line number, run -s or -l.
*/
if (!silent && !all)
for (p1 = buf1, cnt = len; cnt--; )
if (*p1++ == '\n')
++line;
}
}
}
/*
* error --
* print I/O error message and die
*/
void
error(filename)
char *filename;
{
extern int errno;
char *strerror();
if (!silent)
(void) fprintf(stderr, "cmp: %s: %s\n",
filename, strerror(errno));
exit(EXITERR);
}
/*
* endoffile --
* print end-of-file message and exit indicating the files were different
*/
void
endoffile(filename)
char *filename;
{
if (!silent)
(void) fprintf(stderr, "cmp: EOF on %s\n", filename);
exit(EXITDIFF);
}
/*
* usage --
* print usage and die
*/
void
usage()
{
fputs("usage: cmp [-l | -s] file1 file2 [skip1] [skip2]\n", stderr);
exit(EXITERR);
}