linuxdebug/tools/testing/selftests/splice/splice_read.c

58 lines
998 B
C

// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
int main(int argc, char *argv[])
{
int fd;
size_t size;
ssize_t spliced;
if (argc < 2) {
fprintf(stderr, "Usage: %s INPUT [BYTES]\n", argv[0]);
return EXIT_FAILURE;
}
fd = open(argv[1], O_RDONLY);
if (fd < 0) {
perror(argv[1]);
return EXIT_FAILURE;
}
if (argc == 3)
size = atol(argv[2]);
else {
struct stat statbuf;
if (fstat(fd, &statbuf) < 0) {
perror(argv[1]);
return EXIT_FAILURE;
}
if (statbuf.st_size > INT_MAX) {
fprintf(stderr, "%s: Too big\n", argv[1]);
return EXIT_FAILURE;
}
size = statbuf.st_size;
}
/* splice(2) file to stdout. */
spliced = splice(fd, NULL, STDOUT_FILENO, NULL,
size, SPLICE_F_MOVE);
if (spliced < 0) {
perror("splice");
return EXIT_FAILURE;
}
close(fd);
return EXIT_SUCCESS;
}