1 /* comm -- compare two sorted files line by line.
2 Copyright (C) 86, 90, 91, 95, 96, 1997, 1998 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* Written by Richard Stallman and David MacKenzie. */
24 #include <sys/types.h>
26 #include "linebuffer.h"
29 /* Undefine, to avoid warning about redefinition on some systems. */
31 #define min(x, y) ((x) < (y) ? (x) : (y))
33 /* The name this program was run with. */
36 /* If nonzero, print lines that are found only in file 1. */
37 static int only_file_1;
39 /* If nonzero, print lines that are found only in file 2. */
40 static int only_file_2;
42 /* If nonzero, print lines that are found in both files. */
45 /* If nonzero, display usage information and exit. */
48 /* If nonzero, print the version on standard output then exit. */
49 static int show_version;
51 static struct option const long_options[] =
53 {"help", no_argument, &show_help, 1},
54 {"version", no_argument, &show_version, 1},
64 fprintf (stderr, _("Try `%s --help' for more information.\n"),
69 Usage: %s [OPTION]... LEFT_FILE RIGHT_FILE\n\
73 Compare sorted files LEFT_FILE and RIGHT_FILE line by line.\n\
75 -1 suppress lines unique to left file\n\
76 -2 suppress lines unique to right file\n\
77 -3 suppress lines unique to both files\n\
78 --help display this help and exit\n\
79 --version output version information and exit\n\
81 puts (_("\nReport bugs to <textutils-bugs@gnu.org>."));
83 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
86 /* Output the line in linebuffer LINE to stream STREAM
87 provided the switches say it should be output.
88 CLASS is 1 for a line found only in file 1,
89 2 for a line only in file 2, 3 for a line in both. */
92 writeline (struct linebuffer *line, FILE *stream, int class)
104 /* Skip the tab stop for case 1, if we are printing case 1. */
112 /* Skip the tab stop for case 1, if we are printing case 1. */
115 /* Skip the tab stop for case 2, if we are printing case 2. */
121 fwrite (line->buffer, sizeof (char), line->length, stream);
125 /* Compare INFILES[0] and INFILES[1].
126 If either is "-", use the standard input for that file.
127 Assume that each input file is sorted;
128 merge them and output the result.
129 Return 0 if successful, 1 if any errors occur. */
132 compare_files (char **infiles)
134 /* For each file, we have one linebuffer in lb1. */
135 struct linebuffer lb1[2];
137 /* thisline[i] points to the linebuffer holding the next available line
138 in file i, or is NULL if there are no lines left in that file. */
139 struct linebuffer *thisline[2];
141 /* streams[i] holds the input stream for file i. */
146 /* Initialize the storage. */
147 for (i = 0; i < 2; i++)
149 initbuffer (&lb1[i]);
150 thisline[i] = &lb1[i];
151 streams[i] = (STREQ (infiles[i], "-") ? stdin : fopen (infiles[i], "r"));
154 error (0, errno, "%s", infiles[i]);
158 thisline[i] = readline (thisline[i], streams[i]);
161 while (thisline[0] || thisline[1])
165 /* Compare the next available lines of the two files. */
169 else if (!thisline[1])
173 /* Cannot use bcmp -- it only returns a boolean value. */
174 order = memcmp (thisline[0]->buffer, thisline[1]->buffer,
175 min (thisline[0]->length, thisline[1]->length));
177 order = thisline[0]->length - thisline[1]->length;
180 /* Output the line that is lesser. */
182 writeline (thisline[1], stdout, 3);
184 writeline (thisline[1], stdout, 2);
186 writeline (thisline[0], stdout, 1);
188 /* Step the file the line came from.
189 If the files match, step both files. */
191 thisline[1] = readline (thisline[1], streams[1]);
193 thisline[0] = readline (thisline[0], streams[0]);
196 /* Free all storage and close all input streams. */
197 for (i = 0; i < 2; i++)
199 free (lb1[i].buffer);
200 if (ferror (streams[i]) || fclose (streams[i]) == EOF)
202 error (0, errno, "%s", infiles[i]);
206 if (ferror (stdout) || fclose (stdout) == EOF)
208 error (0, errno, _("write error"));
215 main (int argc, char **argv)
219 program_name = argv[0];
220 setlocale (LC_ALL, "");
221 bindtextdomain (PACKAGE, LOCALEDIR);
222 textdomain (PACKAGE);
228 while ((c = getopt_long (argc, argv, "123", long_options, NULL)) != -1)
252 printf ("comm (%s) %s\n", GNU_PACKAGE, VERSION);
259 if (optind + 2 != argc)
262 exit (compare_files (argv + optind) == 0
263 ? EXIT_SUCCESS : EXIT_FAILURE);