Programming

Aloha,

I'm attempting to use a C program to create directories and then use a system call to have another program write .dat files into that directory. I understand that I could use the "system("mkdir directory_name")" function however, I would like my program to create a new directory each time the program loops by incrementing an integer contained in the file name each loop. Here are some example directory names: A1, A2, A3, A4, A5...

I know that this isn't the proper use of the system function, but below is some code that might better illustrate what im trying to do.

main()
{
int i;
for(i=0;i<5;i++)
system("mkdir A%d",i);
}

I also don't mind using a string of characters in an array that I would modify each time I pass through the loop and use as the directory's name.

Does anyone know of a simple way to have a C program create unique directories each time it passes through a loop, by incrementing an integer contained in the file name?

Mahalo,
Windell

You are on the right track, just have to change the syntax of system. You have to do something like this:

Code:

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

int main() {
        int i;
        char command[50];
        for(i=0;i<5;i++) {
                sprintf(command,"mkdir A%d",i);
                system(command);
        }
}

Using system() to invoke the mkdir program is rather expensive. Why not just use the mkdir system call? It would be much faster.

I thought that I'd just fix the OP's code, rather than present a totally new approach. But, here goes:

Code:

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

int main() {
        int i;
        char dirname[50];

        for(i=0;i<10;i++) {
                sprintf(dirname,"A%d",i);
                if((mkdir(dirname,00777))==-1) {
                        fprintf(stdout,"error in creating dir\n");
                }
        }
}

Note: only rudimentary error checking has been implemented in above code.