NetBSD/usr.bin/cmp/cmp.c

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1993-03-21 12:45:37 +03:00
/*
* 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[] = "@(#)cmp.c 5.3 (Berkeley) 6/1/90";
#endif /* not lint */
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#define EXITNODIFF 0
#define EXITDIFF 1
#define EXITERR 2
int all, fd1, fd2, silent;
u_char buf1[MAXBSIZE], buf2[MAXBSIZE];
char *file1, *file2;
main(argc, argv)
int argc;
char *argv[];
{
extern char *optarg;
extern int optind;
int ch;
u_long otoi();
while ((ch = getopt(argc, argv, "-ls")) != EOF)
switch (ch) {
case 'l': /* print all differences */
all = 1;
break;
case 's': /* silent run */
silent = 1;
break;
case '-': /* must be after any flags */
--optind;
goto endargs;
case '?':
default:
usage();
}
endargs:
argv += optind;
argc -= optind;
if (argc < 2 || argc > 4)
usage();
if (all && silent) {
fprintf(stderr,
"cmp: only one of -l and -s may be specified.\n");
exit(EXITERR);
}
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(otoi(argv[2]), fd1, file1);
if (argc == 4)
skip(otoi(argv[3]), fd2, file2);
}
cmp();
/*NOTREACHED*/
}
/*
* skip --
* skip first part of file
*/
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(buf1));
if ((nread = read(fd, buf1, rlen)) != rlen) {
if (nread < 0)
error(fname);
else
endoffile(fname);
}
}
}
cmp()
{
register u_char *p1, *p2;
register int cnt, len1, len2;
register long byte, line;
int dfound = 0;
for (byte = 0, line = 1; ; ) {
switch (len1 = read(fd1, buf1, MAXBSIZE)) {
case -1:
error(file1);
case 0:
/*
* read of file 1 just failed, find out
* if there's anything left in file 2
*/
switch (read(fd2, buf2, 1)) {
case -1:
error(file2);
/* NOTREACHED */
case 0:
exit(dfound ? EXITDIFF : EXITNODIFF);
/* NOTREACHED */
default:
endoffile(file1);
break;
}
}
/*
* file1 might be stdio, which means that a read of less than
* MAXBSIZE might not mean an EOF. So, read whatever we read
* from file1 from file2.
*/
if ((len2 = read(fd2, buf2, len1)) == -1)
error(file2);
if (bcmp(buf1, buf2, len2)) {
if (silent)
exit(EXITDIFF);
if (all) {
dfound = 1;
for (p1 = buf1, p2 = buf2, cnt = len2; 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 += len2;
/*
* 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 = len2; cnt--; )
if (*p1++ == '\n')
++line;
}
/*
* couldn't read as much from file2 as from file1; checked
* here because there might be a difference before we got
* to this point, which would have precedence.
*/
if (len2 < len1)
endoffile(file2);
}
}
/*
* otoi --
* octal/decimal string to u_long
*/
u_long
otoi(s)
register char *s;
{
register u_long val;
register int base;
base = (*s == '0') ? 8 : 10;
for (val = 0; isdigit(*s); ++s)
val = val * base + *s - '0';
return (val);
}
/*
* error --
* print I/O error message and die
*/
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
*/
endoffile(filename)
char *filename;
{
/* 32V put this message on stdout, S5 does it on stderr. */
/* POSIX.2 currently does it on stdout-- Hooray! */
if (!silent)
(void) printf("cmp: EOF on %s\n", filename);
exit(EXITDIFF);
}
/*
* usage --
* print usage and die
*/
usage()
{
fputs("usage: cmp [-ls] file1 file2 [skip1] [skip2]\n", stderr);
exit(EXITERR);
}