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#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <string.h>
int main() {
struct stat s;
int f = open("/towrite", O_WRONLY);
int f2 = open("/toread", O_RDONLY);
printf("f2: %d\n", f2);
fstat(f, &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("ftruncate(10): %d\n", ftruncate(f, 10));
printf("errno: %d\n", errno);
fstat(f, &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("ftruncate(4): %d\n", ftruncate(f, 4));
printf("errno: %d\n", errno);
fstat(f, &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("ftruncate(-1): %d\n", ftruncate(f, -1));
printf("errno: %d\n", errno);
fstat(f, &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("truncate(2): %d\n", truncate("/towrite", 2));
printf("errno: %d\n", errno);
stat("/towrite", &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("truncate(readonly, 2): %d\n", truncate("/toread", 2));
printf("errno: %d\n", errno);
stat("/toread", &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
printf("\n");
printf("ftruncate(readonly, 4): %d\n", ftruncate(f2, 4));
printf("errno: %d\n", errno);
fstat(f2, &s);
printf("st_size: %d\n", s.st_size);
memset(&s, 0, sizeof s);
errno = 0;
return 0;
}
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