bin/comm/comm.c

   1 /*      $OpenBSD: comm.c,v 1.10 2015/10/09 01:37:07 deraadt Exp $       */
   2 /*      $NetBSD: comm.c,v 1.10 1995/09/05 19:57:43 jtc Exp $    */
   3
   4 /*
   5  * Copyright (c) 1989, 1993, 1994
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Case Larsen.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <err.h>
  37 #include <limits.h>
  38 #include <locale.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43
  44 #define MAXLINELEN      (LINE_MAX + 1)
  45
  46 char *tabs[] = { "", "\t", "\t\t" };
  47
  48 FILE   *file(const char *);
  49 void    show(FILE *, char *, char *);
  50 void    usage(void);
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         int comp, file1done, file2done, read1, read2;
  56         int ch, flag1, flag2, flag3;
  57         FILE *fp1, *fp2;
  58         char *col1, *col2, *col3;
  59         char **p, line1[MAXLINELEN], line2[MAXLINELEN];
  60         int (*compare)(const char * ,const char *);
  61
  62         setlocale(LC_ALL, "");
  63
  64         if (pledge("stdio rpath", NULL) == -1)
  65                 err(1, "pledge");
  66
  67         flag1 = flag2 = flag3 = 1;
  68         compare = strcoll;
  69         while ((ch = getopt(argc, argv, "123f")) != -1)
  70                 switch(ch) {
  71                 case '1':
  72                         flag1 = 0;
  73                         break;
  74                 case '2':
  75                         flag2 = 0;
  76                         break;
  77                 case '3':
  78                         flag3 = 0;
  79                         break;
  80                 case 'f':
  81                         compare = strcasecmp;
  82                         break;
  83                 case '?':
  84                 default:
  85                         usage();
  86                 }
  87         argc -= optind;
  88         argv += optind;
  89
  90         if (argc != 2)
  91                 usage();
  92
  93         fp1 = file(argv[0]);
  94         fp2 = file(argv[1]);
  95
  96         /* for each column printed, add another tab offset */
  97         p = tabs;
  98         col1 = col2 = col3 = NULL;
  99         if (flag1)
 100                 col1 = *p++;
 101         if (flag2)
 102                 col2 = *p++;
 103         if (flag3)
 104                 col3 = *p;
 105
 106         for (read1 = read2 = 1;;) {
 107                 /* read next line, check for EOF */
 108                 if (read1)
 109                         file1done = !fgets(line1, MAXLINELEN, fp1);
 110                 if (read2)
 111                         file2done = !fgets(line2, MAXLINELEN, fp2);
 112
 113                 /* if one file done, display the rest of the other file */
 114                 if (file1done) {
 115                         if (!file2done && col2)
 116                                 show(fp2, col2, line2);
 117                         break;
 118                 }
 119                 if (file2done) {
 120                         if (!file1done && col1)
 121                                 show(fp1, col1, line1);
 122                         break;
 123                 }
 124
 125                 /* lines are the same */
 126                 if (!(comp = compare(line1, line2))) {
 127                         read1 = read2 = 1;
 128                         if (col3)
 129                                 if (printf("%s%s", col3, line1) < 0)
 130                                         break;
 131                         continue;
 132                 }
 133
 134                 /* lines are different */
 135                 if (comp < 0) {
 136                         read1 = 1;
 137                         read2 = 0;
 138                         if (col1)
 139                                 if (printf("%s%s", col1, line1) < 0)
 140                                         break;
 141                 } else {
 142                         read1 = 0;
 143                         read2 = 1;
 144                         if (col2)
 145                                 if (printf("%s%s", col2, line2) < 0)
 146                                         break;
 147                 }
 148         }
 149
 150         if (ferror (stdout) || fclose (stdout) == EOF)
 151                 err(1, "stdout");
 152
 153         exit(0);
 154 }
 155
 156 void
 157 show(FILE *fp, char *offset, char *buf)
 158 {
 159         while (printf("%s%s", offset, buf) >= 0 && fgets(buf, MAXLINELEN, fp))
 160                 ;
 161 }
 162
 163 FILE *
 164 file(const char *name)
 165 {
 166         FILE *fp;
 167
 168         if (!strcmp(name, "-"))
 169                 return (stdin);
 170         if ((fp = fopen(name, "r")) == NULL)
 171                 err(1, "%s", name);
 172         return (fp);
 173 }
 174
 175 void
 176 usage(void)
 177 {
 178         (void)fprintf(stderr, "usage: comm [-123f] file1 file2\n");
 179         exit(1);
 180 }