1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #define _GNU_SOURCE
3*4882a593Smuzhiyun #include <errno.h>
4*4882a593Smuzhiyun #include <fcntl.h>
5*4882a593Smuzhiyun #include <limits.h>
6*4882a593Smuzhiyun #include <stdio.h>
7*4882a593Smuzhiyun #include <stdlib.h>
8*4882a593Smuzhiyun #include <unistd.h>
9*4882a593Smuzhiyun #include <sys/types.h>
10*4882a593Smuzhiyun #include <sys/stat.h>
11*4882a593Smuzhiyun
main(int argc,char * argv[])12*4882a593Smuzhiyun int main(int argc, char *argv[])
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun int fd;
15*4882a593Smuzhiyun size_t size;
16*4882a593Smuzhiyun ssize_t spliced;
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun if (argc < 2) {
19*4882a593Smuzhiyun fprintf(stderr, "Usage: %s INPUT [BYTES]\n", argv[0]);
20*4882a593Smuzhiyun return EXIT_FAILURE;
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun fd = open(argv[1], O_RDONLY);
24*4882a593Smuzhiyun if (fd < 0) {
25*4882a593Smuzhiyun perror(argv[1]);
26*4882a593Smuzhiyun return EXIT_FAILURE;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun if (argc == 3)
30*4882a593Smuzhiyun size = atol(argv[2]);
31*4882a593Smuzhiyun else {
32*4882a593Smuzhiyun struct stat statbuf;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun if (fstat(fd, &statbuf) < 0) {
35*4882a593Smuzhiyun perror(argv[1]);
36*4882a593Smuzhiyun return EXIT_FAILURE;
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun if (statbuf.st_size > INT_MAX) {
40*4882a593Smuzhiyun fprintf(stderr, "%s: Too big\n", argv[1]);
41*4882a593Smuzhiyun return EXIT_FAILURE;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun size = statbuf.st_size;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun /* splice(2) file to stdout. */
48*4882a593Smuzhiyun spliced = splice(fd, NULL, STDOUT_FILENO, NULL,
49*4882a593Smuzhiyun size, SPLICE_F_MOVE);
50*4882a593Smuzhiyun if (spliced < 0) {
51*4882a593Smuzhiyun perror("splice");
52*4882a593Smuzhiyun return EXIT_FAILURE;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun close(fd);
56*4882a593Smuzhiyun return EXIT_SUCCESS;
57*4882a593Smuzhiyun }
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