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/* comm -- compare two sorted files line by line.
Copyright (C) 1986, 1990, 1991, 1995 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Richard Stallman and David MacKenzie. */
#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"
#include "linebuffer.h"
#include "version.h"
#include "error.h"
/* Undefine, to avoid warning about redefinition on some systems. */
#undef min
#define min(x, y) ((x) < (y) ? (x) : (y))
/* The name this program was run with. */
char *program_name;
/* If nonzero, print lines that are found only in file 1. */
static int only_file_1;
/* If nonzero, print lines that are found only in file 2. */
static int only_file_2;
/* If nonzero, print lines that are found in both files. */
static int both;
/* If nonzero, display usage information and exit. */
static int show_help;
/* If nonzero, print the version on standard output then exit. */
static int show_version;
static struct option const long_options[] =
{
{"help", no_argument, &show_help, 1},
{"version", no_argument, &show_version, 1},
{0, 0, 0, 0}
};
static void
usage (int status)
{
if (status != 0)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("\
Usage: %s [OPTION]... LEFT_FILE RIGHT_FILE\n\
"),
program_name);
printf (_("\
Compare sorted files LEFT_FILE and RIGHT_FILE line by line.\n\
\n\
-1 suppress lines unique to left file\n\
-2 suppress lines unique to right file\n\
-3 suppress lines unique to both files\n\
--help display this help and exit\n\
--version output version information and exit\n\
"));
}
exit (status);
}
/* Output the line in linebuffer LINE to stream STREAM
provided the switches say it should be output.
CLASS is 1 for a line found only in file 1,
2 for a line only in file 2, 3 for a line in both. */
static void
writeline (struct linebuffer *line, FILE *stream, int class)
{
switch (class)
{
case 1:
if (!only_file_1)
return;
break;
case 2:
if (!only_file_2)
return;
/* Skip the tab stop for case 1, if we are printing case 1. */
if (only_file_1)
putc ('\t', stream);
break;
case 3:
if (!both)
return;
/* Skip the tab stop for case 1, if we are printing case 1. */
if (only_file_1)
putc ('\t', stream);
/* Skip the tab stop for case 2, if we are printing case 2. */
if (only_file_2)
putc ('\t', stream);
break;
}
fwrite (line->buffer, sizeof (char), line->length, stream);
putc ('\n', stream);
}
/* Compare INFILES[0] and INFILES[1].
If either is "-", use the standard input for that file.
Assume that each input file is sorted;
merge them and output the result.
Return 0 if successful, 1 if any errors occur. */
static int
compare_files (char **infiles)
{
/* For each file, we have one linebuffer in lb1. */
struct linebuffer lb1[2];
/* thisline[i] points to the linebuffer holding the next available line
in file i, or is NULL if there are no lines left in that file. */
struct linebuffer *thisline[2];
/* streams[i] holds the input stream for file i. */
FILE *streams[2];
int i, ret = 0;
/* Initialize the storage. */
for (i = 0; i < 2; i++)
{
initbuffer (&lb1[i]);
thisline[i] = &lb1[i];
streams[i] = strcmp (infiles[i], "-")
? fopen (infiles[i], "r") : stdin;
if (!streams[i])
{
error (0, errno, "%s", infiles[i]);
return 1;
}
thisline[i] = readline (thisline[i], streams[i]);
}
while (thisline[0] || thisline[1])
{
int order;
/* Compare the next available lines of the two files. */
if (!thisline[0])
order = 1;
else if (!thisline[1])
order = -1;
else
{
/* Cannot use bcmp -- it only returns a boolean value. */
order = memcmp (thisline[0]->buffer, thisline[1]->buffer,
min (thisline[0]->length, thisline[1]->length));
if (order == 0)
order = thisline[0]->length - thisline[1]->length;
}
/* Output the line that is lesser. */
if (order == 0)
writeline (thisline[1], stdout, 3);
else if (order > 0)
writeline (thisline[1], stdout, 2);
else
writeline (thisline[0], stdout, 1);
/* Step the file the line came from.
If the files match, step both files. */
if (order >= 0)
thisline[1] = readline (thisline[1], streams[1]);
if (order <= 0)
thisline[0] = readline (thisline[0], streams[0]);
}
/* Free all storage and close all input streams. */
for (i = 0; i < 2; i++)
{
free (lb1[i].buffer);
if (ferror (streams[i]) || fclose (streams[i]) == EOF)
{
error (0, errno, "%s", infiles[i]);
ret = 1;
}
}
if (ferror (stdout) || fclose (stdout) == EOF)
{
error (0, errno, _("write error"));
ret = 1;
}
return ret;
}
void
main (int argc, char **argv)
{
int c;
program_name = argv[0];
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
only_file_1 = 1;
only_file_2 = 1;
both = 1;
while ((c = getopt_long (argc, argv, "123", long_options, (int *) 0)) != EOF)
switch (c)
{
case 0:
break;
case '1':
only_file_1 = 0;
break;
case '2':
only_file_2 = 0;
break;
case '3':
both = 0;
break;
default:
usage (1);
}
if (show_version)
{
printf ("comm - %s\n", version_string);
exit (0);
}
if (show_help)
usage (0);
if (optind + 2 != argc)
usage (1);
exit (compare_files (argv + optind));
}
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