save the output of child process

In Gnome desktop manager, you have virtual desktops or workspace. Click here if u don't know what virtual desktop is:
http://www.mozillaquest.com/Linux4Wi..._Story-01.html

Now, assume you have program called "stupid" that can guess what workspace u r in now. Assume you are in workspace number one and in console you type:
$ stupid
The stupid person are in workspace 0
You go to workspace number 2 and run it again:
$ stupid
The stupid person are in workspace 1

Now I want to make wallpaper changer according to this program. This is my idea. I make the daemon and check every half second with this function:

Code:

---

string bullStrong;
while(TRUE) {
        execlp("stupid", NULL);
        //I want to save the stdout of this child process to string
        //but I don't know how
        bullStrong = howDoISaveIt();
        //some code here
        ChangeTheWallpaper(bullStrong);
}

---

Would you help me write the howDoISaveIt() function please?

Use popen()

http://www.cs.cf.ac.uk/Dave/C/node23...00000000000000

Quote:

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Originally Posted by Hammer

http://www.cs.cf.ac.uk/Dave/C/node23...00000000000000

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I have read that before I post my question, Hammer but it is stupidly hard for newbie to understand. Well, if newbie want to know how to save the output of child process and accidentally stop in this thread, here how I do it:

Code:

---

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

int main()
{
    FILE *read_fp;
    char buffer[BUFSIZ + 1];
    int chars_read;
    memset(buffer, '\0', sizeof(buffer));
    read_fp = popen("uname -a", "r");
    if (read_fp != NULL) {
        chars_read = fread(buffer, sizeof(char), BUFSIZ, read_fp);
        if (chars_read > 0) {
            printf("Output was:-\n%s\n", buffer);
        }
        pclose(read_fp);
        exit(EXIT_SUCCESS);
    }
    exit(EXIT_FAILURE);
}

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That code is copyrighted. I downloaded code for "Beginning Linux Programming" free of charge from here:
http://www.wrox.com/dynamic/books/download.aspx

You got a lot of sample code that easy to understand. That's all, babe.