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/*
Copyright (C) 2012 - 2015 Andreas Baumann <mail@andreasbaumann.cc>
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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
int main( void )
{
char buf[4096];
int fd;
int res;
ssize_t wres;
struct stat s;
/* Make sure no file is around from last invocation */
(void)unlink( "./mnt/testopen" );
/* This should succeed */
fd = open( "./mnt/testopen", O_CREAT | O_EXCL | O_WRONLY, S_IRUSR | S_IWUSR );
if( fd < 0 ) {
perror( "Unable to create testopen" );
return 1;
}
/* write some data into it so we know if truncate really works */
memset( buf, 0, 4096 );
wres = write( fd, buf, 4096 );
if( wres != 4096 ) {
perror( "Error writing" );
(void)close( fd );
return 1;
}
(void)close( fd );
/* check if the file has size 4096 */
res = stat( "./mnt/testopen", &s );
if( res < 0 ) {
perror( "Error stating testopen" );
return 1;
}
if( s.st_size == 4096 ) {
// OK
} else {
fprintf( stderr, "Size of file should be 4096, but is %jd\n", s.st_size );
return 1;
}
/* Second one should fail with EEXIST */
fd = open( "./mnt/testopen", O_CREAT | O_EXCL | O_WRONLY, S_IRUSR | S_IWUSR );
if( fd < 0 && errno == EEXIST ) {
// OK
} else {
fprintf( stderr, "Second create succedded and should not" );
return 1;
}
/* Third one should success and append to the file */
fd = open( "./mnt/testopen", O_CREAT | O_WRONLY | O_APPEND, S_IRUSR | S_IWUSR );
/* check if the file has size 4096 */
res = stat( "./mnt/testopen", &s );
if( res < 0 ) {
perror( "Error stating testopen" );
return 1;
}
if( s.st_size == 4096 ) {
// OK
} else {
fprintf( stderr, "Size of file should be 4096, but is %jd\n", s.st_size );
return 1;
}
/* write some more data, this data should be appended */
wres = write( fd, buf, 4096 );
if( wres != 4096 ) {
perror( "Error writing" );
(void)close( fd );
return 1;
}
(void)close( fd );
/* check if the file has size 2 * 4096 now */
res = stat( "./mnt/testopen", &s );
if( res < 0 ) {
perror( "Error stating testopen" );
return 1;
}
if( s.st_size == 8192 ) {
// OK
} else {
fprintf( stderr, "Size of file should be 8192, but is %jd\n", s.st_size );
return 1;
}
/* Fourth one should success and truncate the file */
fd = open( "./mnt/testopen", O_CREAT | O_WRONLY | O_TRUNC, S_IRUSR | S_IWUSR );
(void)close( fd );
/* check if the file has size zero */
res = stat( "./mnt/testopen", &s );
if( res < 0 ) {
perror( "Error stating testopen" );
return 1;
}
if( s.st_size == 0 ) {
// OK
} else {
fprintf( stderr, "Size of file should be 0, but is %jd\n", s.st_size );
return 1;
}
res = unlink( "./mnt/testopen" );
if( res < 0 ) {
perror( "Error removing testopen" );
return 1;
}
return 0;
}
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