1 /* comm -- compare two sorted files line by line.
2 Copyright (C) 1986, 1990, 1991, 1995 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
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
18 /* Written by Richard Stallman and David MacKenzie. */
24 #include <sys/types.h>
26 #include "linebuffer.h"
30 #define min(x, y) ((x) < (y) ? (x) : (y))
32 /* The name this program was run with. */
35 /* If nonzero, print lines that are found only in file 1. */
36 static int only_file_1;
38 /* If nonzero, print lines that are found only in file 2. */
39 static int only_file_2;
41 /* If nonzero, print lines that are found in both files. */
44 /* If non-zero, display usage information and exit. */
47 /* If non-zero, print the version on standard output then exit. */
48 static int show_version;
50 static struct option const long_options[] =
52 {"help", no_argument, &show_help, 1},
53 {"version", no_argument, &show_version, 1},
57 static int compare_files ();
58 static void writeline ();
68 program_name = argv[0];
74 while ((c = getopt_long (argc, argv, "123", long_options, (int *) 0)) != EOF)
98 printf ("comm - %s\n", version_string);
105 if (optind + 2 != argc)
108 exit (compare_files (argv + optind));
111 /* Compare INFILES[0] and INFILES[1].
112 If either is "-", use the standard input for that file.
113 Assume that each input file is sorted;
114 merge them and output the result.
115 Return 0 if successful, 1 if any errors occur. */
118 compare_files (infiles)
121 /* For each file, we have one linebuffer in lb1. */
122 struct linebuffer lb1[2];
124 /* thisline[i] points to the linebuffer holding the next available line
125 in file i, or is NULL if there are no lines left in that file. */
126 struct linebuffer *thisline[2];
128 /* streams[i] holds the input stream for file i. */
133 /* Initialize the storage. */
134 for (i = 0; i < 2; i++)
136 initbuffer (&lb1[i]);
137 thisline[i] = &lb1[i];
138 streams[i] = strcmp (infiles[i], "-")
139 ? fopen (infiles[i], "r") : stdin;
142 error (0, errno, "%s", infiles[i]);
146 thisline[i] = readline (thisline[i], streams[i]);
149 while (thisline[0] || thisline[1])
153 /* Compare the next available lines of the two files. */
157 else if (!thisline[1])
161 /* Cannot use bcmp -- it only returns a boolean value. */
162 order = memcmp (thisline[0]->buffer, thisline[1]->buffer,
163 min (thisline[0]->length, thisline[1]->length));
165 order = thisline[0]->length - thisline[1]->length;
168 /* Output the line that is lesser. */
170 writeline (thisline[1], stdout, 3);
172 writeline (thisline[1], stdout, 2);
174 writeline (thisline[0], stdout, 1);
176 /* Step the file the line came from.
177 If the files match, step both files. */
179 thisline[1] = readline (thisline[1], streams[1]);
181 thisline[0] = readline (thisline[0], streams[0]);
184 /* Free all storage and close all input streams. */
185 for (i = 0; i < 2; i++)
187 free (lb1[i].buffer);
188 if (ferror (streams[i]) || fclose (streams[i]) == EOF)
190 error (0, errno, "%s", infiles[i]);
194 if (ferror (stdout) || fclose (stdout) == EOF)
196 error (0, errno, "write error");
202 /* Output the line in linebuffer LINE to stream STREAM
203 provided the switches say it should be output.
204 CLASS is 1 for a line found only in file 1,
205 2 for a line only in file 2, 3 for a line in both. */
208 writeline (line, stream, class)
209 struct linebuffer *line;
223 /* Skip the tab stop for case 1, if we are printing case 1. */
231 /* Skip the tab stop for case 1, if we are printing case 1. */
234 /* Skip the tab stop for case 2, if we are printing case 2. */
240 fwrite (line->buffer, sizeof (char), line->length, stream);
249 fprintf (stderr, "Try `%s --help' for more information.\n",
254 Usage: %s [OPTION]... LEFT_FILE RIGHT_FILE\n\
259 -1 suppress lines unique to left file\n\
260 -2 suppress lines unique to right file\n\
261 -3 suppress lines unique to both files\n\
262 --help display this help and exit\n\
263 --version output version information and exit\n\