[C] Simple example for create file

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

int main(void)
{
    FILE *fp;
    char buffer[256] = {'\0'};


    sprintf(&buffer[0], "/tmp/ca.txt");                                            
    fp = fopen(&buffer[0], "w");                                                                  
    chmod(&buffer[0], S_IRUSR|S_IWUSR);                                                           
    sprintf(&buffer[0], "vpn_crt_server_ca_key");                                    
    fprintf(fp, "%s\n", &buffer[0]);                                       
    fclose(fp);
}

Reference:

• GITHUB - asuswrt-merlin/release/src/router/rc/openvpn.c