glibc/manual/examples/popen.c

56 lines
1.4 KiB
C

/* Pipe to a Subprocess
Copyright (C) 1991-2016 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
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, if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
void
write_data (FILE * stream)
{
int i;
for (i = 0; i < 100; i++)
fprintf (stream, "%d\n", i);
if (ferror (stream))
{
fprintf (stderr, "Output to stream failed.\n");
exit (EXIT_FAILURE);
}
}
/*@group*/
int
main (void)
{
FILE *output;
output = popen ("more", "w");
if (!output)
{
fprintf (stderr,
"incorrect parameters or too many files.\n");
return EXIT_FAILURE;
}
write_data (output);
if (pclose (output) != 0)
{
fprintf (stderr,
"Could not run more or other error.\n");
}
return EXIT_SUCCESS;
}
/*@end group*/