fork/exec problem

djgerbavore · 04-13-2006, 09:23 PM

hi,
I'm tryign to get exec to list a directory that isn't in my PWD. for example a directory called /mnt/test.
my code is

Code:

void
ls_directory()
{
        int c_pid, status;
        c_pid = fork();

        if(c_pid == 0) {
                char *args[] = { "/mnt/test", (char *)0 };
                execv("/bin/ls", args);
                exit(1);

        } else {
                while(wait(&status) != c_pid);
        }

}

but for some reason the program still list the directory i currently runnign the program. Is there a way to ls a directory that isn't in my pwd?

thanks,

djgerbavor3

djgerbavore · 04-13-2006, 09:52 PM

after doing some reading and hacking i got it to work;
from reading I learned this @ http://www.unix.org.ua/orelly/unix/upt/ch38_02.htm

Quote:

...because a child process can't affect its parent's environment (38.3), some commands don't make sense as separate processes. For example, cd must be built in, or it couldn't change the working directory for the current shell.

here is how i got it

Code:

void
ls_directory()
{
        int c_pid, status;
        c_pid = fork();

        if(c_pid == 0) {
                char *args[] = { "-l","-al", "/mnt/test", (char *)0 };
                execv("/bin/ls", args);
                exit(1);

        } else {
                while(wait(&status) != c_pid);
        }

}

this got me the desire affect

thanks,
djgeravor3

95se · 04-13-2006, 11:13 PM

I think it's actually because the first argument should be the program's name. You args should look like this,

Code:

char *args[] = { "ls", "/mnt/test", (char *)0 };