utils/src/cmp.c

145 lines
3.0 KiB
C

/* $Id$ */
/* Copyright (c) 2009 Pierre Pronchery <khorben@defora.org> */
/* This file is part of DeforaOS Unix utils */
/* 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, version 3 of the License.
*
* 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, see <http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <stdio.h>
#include <string.h>
/* types */
typedef enum _OutputType
{
OT_NONE,
OT_LONG,
OT_DEFAULT
} OutputType;
/* cmp */
static int _cmp_error(char const * message, int ret);
static int _cmp_files(OutputType ot, char const * file1, char const * file2,
FILE * fp1, FILE * fp2);
static int _cmp(OutputType ot, char const * file1, char const * file2)
{
FILE * fp1;
FILE * fp2;
if(strcmp("-", file1) == 0)
fp1 = stdin;
else if((fp1 = fopen(file1, "r")) == NULL)
return _cmp_error(file1, 1);
if(strcmp("-", file2) == 0)
fp2 = stdin;
else if((fp2 = fopen(file2, "r")) == NULL)
{
_cmp_error(file2, 0);
if(fp1 != stdin && fclose(fp1) != 0)
return _cmp_error(file1, 1);
return 1;
}
return _cmp_files(ot, file1, file2, fp1, fp2);
}
static int _cmp_error(char const * message, int ret)
{
fputs("cmp: ", stderr);
perror(message);
return ret;
}
static int _cmp_files(OutputType ot, char const * file1, char const * file2,
FILE * fp1, FILE * fp2)
{
int ret = 0;
int c1;
int c2;
unsigned int byte = 1;
unsigned int line = 1;
while(1)
{
c1 = fgetc(fp1);
c2 = fgetc(fp2);
if(c1 == EOF && c2 == EOF)
break;
if(c1 == EOF || c2 == EOF)
{
if(ot != OT_NONE)
fprintf(stderr, "%s%s\n", "cmp: EOF on ",
c1 == EOF ? file1 : file2);
ret = 1;
break;
}
if(c1 != c2)
{
ret = 1;
if(ot == OT_DEFAULT)
{
printf("%s %s differ: char %u, line %u\n",
file1, file2, byte, line);
break;
}
else if(ot == OT_LONG)
printf("%d %o %o\n", byte, c1, c2);
else
break;
}
if(c1 == '\n')
line++;
byte++;
}
if(fp1 != stdin && fclose(fp1) != 0)
ret |= _cmp_error(file1, 1);
if(fp2 != stdin && fclose(fp2) != 0)
ret |= _cmp_error(file2, 1);
return ret;
}
/* usage */
static int _usage(void)
{
fputs("Usage: cmp [-l|-s] file1 file2\n\
-l Write the byte number and the differing byte for each difference\n\
-s Write nothing for differing bytes\n", stderr);
return 2;
}
/* main */
int main(int argc, char * argv[])
{
OutputType ot = OT_DEFAULT;
int o;
while((o = getopt(argc, argv, "ls")) != -1)
switch(o)
{
case 'l':
ot = OT_LONG;
break;
case 's':
ot = OT_NONE;
break;
default:
return _usage();
}
if(argc - optind != 2)
return _usage();
return (_cmp(ot, argv[optind], argv[optind + 1]) == 0) ? 0 : 2;
}