37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
// Writes data to a file which is readable and writable by the user by
|
|
// specificying permissions
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
|
|
#define BUFSIZE 128
|
|
|
|
int main(int argc, char *argv[]){
|
|
char *outfile = "readable.txt";
|
|
|
|
printf("Opening file %s\n",outfile);
|
|
mode_t mode = S_IRUSR | S_IWUSR;
|
|
int out_fd = open(outfile,O_WRONLY | O_CREAT, mode); // open for writing and create if needed, WITH PERMISSIONS
|
|
if(out_fd == -1){ // check result and fail if not opened
|
|
perror("Couldn't open output file");
|
|
exit(1);
|
|
}
|
|
|
|
printf("Writing to file %s\n",outfile);
|
|
char outbuf[BUFSIZE] = "here is some text to write"; // what to write
|
|
int bytes_written = write(out_fd, outbuf, BUFSIZE); // do th write
|
|
if(bytes_written == -1){ // check for errors
|
|
perror("Failed to read from file");
|
|
exit(1);
|
|
}
|
|
printf("Wrote %d bytes to %s\n",bytes_written,outfile);
|
|
|
|
if(close(out_fd) == -1){ // check for errors on close
|
|
perror("Couldn't close file");
|
|
}
|
|
|
|
return 0;
|
|
}
|