macOS mkdir in C does not work

[giha]

Hi,

i am trying to create a cache folder in C for the current user.
In terminal i type: mkdir ~/Library/Caches/atest and it works,
but when i write it in C it failed to work. What's wrong? Thanks!

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>


int main (int argc, const char * argv[]) {
    // insert code here...
    printf("Hello, World!\n");

	mkdir("~/Library/Caches/atest", 0777);

    return 0;
}

 

[chown33]

mkdir("~/Library/Caches/atest", 0777);

C functions don't understand the ~ convention. That's a shell feature, and the shell expands ~'s before passing a value as a command arg.

I strongly recommend adding actual error-checking to your code. If you test the return value and then examine the value of errno on errors, the reason would be a little clearer. Also see 'man perror' for a function that prints messages for errno.

Also write yourself a command that does nothing but print its args, one per line, numbered. Then run it like this:

./mycmd ~/Library/Caches/atest

and see what it outputs. In my view, this should be the second program a student writes, right after HelloWorld. It's not only a useful exercise for learning C, it's a useful tool for understanding args passed to commands.

 

[giha]

perror is useful. Thank you for clear me up