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#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
ssize_t
nwrite(int fd, const void *buf, size_t count)
{
ssize_t ret = 0;
ssize_t written = 0;
for (written = 0; written != count; written += ret) {
ret = write(fd, buf + written, count - written);
if (ret < 0) {
if (errno == EINTR)
ret = 0;
else
goto out;
}
}
ret = written;
out:
return ret;
}
int
file_write(char *filename, int bs, int count)
{
int fd = 0;
int ret = -1;
int i = 0;
char *buf = NULL;
bs = bs * 1024;
buf = (char *)malloc(bs);
if (buf == NULL)
goto out;
memset(buf, 0, bs);
fd = open(filename, O_RDWR | O_CREAT | O_SYNC, 0600);
while (i < count) {
ret = nwrite(fd, buf, bs);
if (ret == -1) {
close(fd);
goto out;
}
i++;
}
ret = fdatasync(fd);
if (ret) {
close(fd);
goto out;
}
ret = close(fd);
if (ret)
goto out;
ret = 0;
out:
if (buf)
free(buf);
return ret;
}
int
main(int argc, char **argv)
{
if (argc != 4) {
printf("Usage: %s <filename> <block size in k> <count>\n", argv[0]);
return EXIT_FAILURE;
}
if (file_write(argv[1], atoi(argv[2]), atoi(argv[3])) < 0) {
perror("write failed");
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
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