C function to close all open file descriptors on Linux

close_file_descriptors.c

#include<stdio.h>
#include<stdlib.h>
#include<dirent.h>

int close_FDs()
{
    unsigned int fd;
    DIR* dp;
    struct dirent* ep;
    dp = opendir("/proc/self/fd");
    if (dp != NULL) {
        // first two entries are . and ..
        readdir(dp);
        readdir(dp);

        while (ep = readdir(dp))
            if (sscanf(ep->d_name, "%u", &fd) != EOF)
                close(fd);
        closedir(dp);
      
        return 0;
    } else {
      return 1;
    }
}