BSD 4_4_Lite1 release

[unix-history] / usr / src / usr.bin / comm / comm.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);
}