Imitate “cat >” command in c (LINUX/UNIX)

Question

I need to imitate the command: "cat > " using c with exec family.

I cant find a way to do it because it doesn't recognize the symbol '>', I've already tried using execlp but maybe my syntax is wrong.

Thanks for the help. appreciated.

Answer 1

The command is cat . The > is interpreted by the shell, redirecting the stdout of the command to a specific file.

Thus, you would need to connect the stdout (file descriptor 1) of the process running cat to a file:

/* emulating `cat >file` */
int fd = open("file", …);
/* use our own fd 1 */
dup2(fd, 1);
close(fd);
/* with new stdout, exec `cat` */
exec("cat");