freebsd-dev/usr.bin/comm/comm.c
1994-05-27 12:33:43 +00:00

187 lines
4.4 KiB
C

/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Case Larsen.
*
* 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
static char copyright[] =
"@(#) Copyright (c) 1989, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)comm.c 8.3 (Berkeley) 4/2/94";
#endif /* not lint */
#include <fcntl.h>
#include <limits.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXLINELEN (LINE_MAX + 1)
char *tabs[] = { "", "\t", "\t\t" };
FILE *file __P((char *));
void show __P((FILE *, char *, char *));
void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
int comp, file1done, file2done, read1, read2;
int ch, flag1, flag2, flag3;
FILE *fp1, *fp2;
char *col1, *col2, *col3;
char **p, line1[MAXLINELEN], line2[MAXLINELEN];
flag1 = flag2 = flag3 = 1;
while ((ch = getopt(argc, argv, "-123")) != EOF)
switch(ch) {
case '-':
--optind;
goto done;
case '1':
flag1 = 0;
break;
case '2':
flag2 = 0;
break;
case '3':
flag3 = 0;
break;
case '?':
default:
usage();
}
done: argc -= optind;
argv += optind;
if (argc != 2)
usage();
fp1 = file(argv[0]);
fp2 = file(argv[1]);
/* for each column printed, add another tab offset */
p = tabs;
col1 = col2 = col3 = NULL;
if (flag1)
col1 = *p++;
if (flag2)
col2 = *p++;
if (flag3)
col3 = *p;
for (read1 = read2 = 1;;) {
/* read next line, check for EOF */
if (read1)
file1done = !fgets(line1, MAXLINELEN, fp1);
if (read2)
file2done = !fgets(line2, MAXLINELEN, fp2);
/* if one file done, display the rest of the other file */
if (file1done) {
if (!file2done && col2)
show(fp2, col2, line2);
break;
}
if (file2done) {
if (!file1done && col1)
show(fp1, col1, line1);
break;
}
/* lines are the same */
if (!(comp = strcmp(line1, line2))) {
read1 = read2 = 1;
if (col3)
(void)printf("%s%s", col3, line1);
continue;
}
/* lines are different */
if (comp < 0) {
read1 = 1;
read2 = 0;
if (col1)
(void)printf("%s%s", col1, line1);
} else {
read1 = 0;
read2 = 1;
if (col2)
(void)printf("%s%s", col2, line2);
}
}
exit(0);
}
void
show(fp, offset, buf)
FILE *fp;
char *offset, *buf;
{
do {
(void)printf("%s%s", offset, buf);
} while (fgets(buf, MAXLINELEN, fp));
}
FILE *
file(name)
char *name;
{
FILE *fp;
if (!strcmp(name, "-"))
return (stdin);
if ((fp = fopen(name, "r")) == NULL) {
(void)fprintf(stderr, "comm: %s: %s\n", name, strerror(errno));
exit(1);
}
return (fp);
}
void
usage()
{
(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
exit(1);
}