usr.bin/comm/comm.c

   1 /*      $NetBSD: comm.c,v 1.17 2009/04/11 12:18:45 lukem Exp $  */
   2
   3 /*
   4  * Copyright (c) 1989, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Case Larsen.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #ifndef lint
  37 __COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\
  38  The Regents of the University of California.  All rights reserved.");
  39 #endif /* not lint */
  40
  41 #ifndef lint
  42 #if 0
  43 static char sccsid[] = "@(#)comm.c      8.4 (Berkeley) 5/4/95";
  44 #endif
  45 __RCSID("$NetBSD: comm.c,v 1.17 2009/04/11 12:18:45 lukem Exp $");
  46 #endif /* not lint */
  47
  48 #include <err.h>
  49 #include <limits.h>
  50 #include <locale.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 #define MAXLINELEN      (LINE_MAX + 1)
  57
  58 const char *tabs[] = { "", "\t", "\t\t" };
  59
  60 FILE   *file(const char *);
  61 void    show(FILE *, const char *, char *);
  62 void    usage(void);
  63 char   *getnextln(char *buf, FILE *);
  64
  65 int
  66 main(int argc, char **argv)
  67 {
  68         int comp, file1done, file2done, read1, read2;
  69         int ch, flag1, flag2, flag3;
  70         FILE *fp1, *fp2;
  71         const char *col1, *col2, *col3, **p;
  72         char line1[MAXLINELEN], line2[MAXLINELEN];
  73         int (*compare)(const char*,const char*);
  74
  75         (void)setlocale(LC_ALL, "");
  76
  77         file1done = file2done = 0;
  78         flag1 = flag2 = flag3 = 1;
  79         compare = strcoll;
  80         while ((ch = getopt(argc, argv, "123f")) != -1)
  81                 switch(ch) {
  82                 case '1':
  83                         flag1 = 0;
  84                         break;
  85                 case '2':
  86                         flag2 = 0;
  87                         break;
  88                 case '3':
  89                         flag3 = 0;
  90                         break;
  91                 case 'f':
  92                         compare = strcasecmp;
  93                         break;
  94                 case '?':
  95                 default:
  96                         usage();
  97                 }
  98         argc -= optind;
  99         argv += optind;
 100
 101         if (argc != 2)
 102                 usage();
 103
 104         fp1 = file(argv[0]);
 105         fp2 = file(argv[1]);
 106
 107         /* for each column printed, add another tab offset */
 108         p = tabs;
 109         col1 = col2 = col3 = NULL;
 110         if (flag1)
 111                 col1 = *p++;
 112         if (flag2)
 113                 col2 = *p++;
 114         if (flag3)
 115                 col3 = *p;
 116
 117         for (read1 = read2 = 1;;) {
 118                 /* read next line, check for EOF */
 119                 if (read1)
 120                         file1done = !getnextln(line1, fp1);
 121                 if (read2)
 122                         file2done = !getnextln(line2, fp2);
 123
 124                 /* if one file done, display the rest of the other file */
 125                 if (file1done) {
 126                         if (!file2done && col2)
 127                                 show(fp2, col2, line2);
 128                         break;
 129                 }
 130                 if (file2done) {
 131                         if (!file1done && col1)
 132                                 show(fp1, col1, line1);
 133                         break;
 134                 }
 135
 136                 /* lines are the same */
 137                 if (!(comp = compare(line1, line2))) {
 138                         read1 = read2 = 1;
 139                         if (col3)
 140                                 if (printf("%s%s\n", col3, line1) < 0)
 141                                         break;
 142                         continue;
 143                 }
 144
 145                 /* lines are different */
 146                 if (comp < 0) {
 147                         read1 = 1;
 148                         read2 = 0;
 149                         if (col1)
 150                                 if (printf("%s%s\n", col1, line1) < 0)
 151                                         break;
 152                 } else {
 153                         read1 = 0;
 154                         read2 = 1;
 155                         if (col2)
 156                                 if (printf("%s%s\n", col2, line2) < 0)
 157                                         break;
 158                 }
 159         }
 160
 161         if (ferror (stdout) || fclose (stdout) == EOF)
 162                 err(1, "stdout");
 163
 164         exit(0);
 165 }
 166
 167 void
 168 show(FILE *fp, const char *offset, char *buf)
 169 {
 170         while (printf("%s%s\n", offset, buf) >= 0 && getnextln(buf, fp))
 171                 ;
 172 }
 173
 174 FILE *
 175 file(const char *name)
 176 {
 177         FILE *fp;
 178
 179         if (!strcmp(name, "-"))
 180                 return (stdin);
 181         if ((fp = fopen(name, "r")) == NULL)
 182                 err(1, "%s", name);
 183         return (fp);
 184 }
 185
 186 void
 187 usage(void)
 188 {
 189
 190         (void)fprintf(stderr, "usage: comm [-123f] file1 file2\n");
 191         exit(1);
 192 }
 193
 194 char *
 195 getnextln(char *buf, FILE *fp)
 196 {
 197         size_t i = 0;
 198         int c;
 199
 200         while ((c = fgetc(fp)) != '\n' && c != EOF) {
 201                 buf[i++] = c;
 202
 203                 if (i >= MAXLINELEN)
 204                         i--; /* consumes extra characters till newline */
 205         }
 206
 207         if (c == EOF && !i)
 208                 return NULL;
 209
 210         buf[i] = 0;
 211         return buf;
 212 }
 213