Programming

I was thinking to use gksudo. Is there anyway to see if these commands were successfully accomplished?
E.g.
gksudo -i > alex
And then if password confirmation will be successful, "1" or "successful" will be writen to file "alex"
Is this or something similar possible?

A few things...
1) You haven't given sudo anything to do, so I don't think that will work. If you want to change the password, why not sudo -u username passwd username? That will request the user's login and, only if successful, prompt him to change the password.

2) I don't think you really want to capture the output here, do you? You want the user to see it and interact with it. Using gksudo instead of sudo in a terminal means you don't get all this nice prewritten tested-to-death software to use(no google hits for gkpasswd). Why not use it?

3) Check the program's return status, not it's output. If you're unsure what an exit status is, try this from shell:

Code:

$ true ; echo $?
0
$ false ; echo $?
1
$ true && echo 'This succeeded'
This succeeded
$ false && echo 'This succeeded'
$ true || echo 'This failed'
$ false || echo 'This failed'
This failed
$

And the following program should do this:

Code:

int main(void)
{
       return(42);
}

Code:

$ ./return42 ; echo $?
42
$

Traditionally programs return 0 on success, nonzero on failure. Just check if it returned zero and you'll know if it succeeded.

Ok thx for the help. I knew that every program returns a value. How do I exactly check the returned value?

Depends how exactly you ran it. How are you running it?

I am thinking of using the system function at stdlib.h calling gksudo. Then writing a value to a file or something and then, through C++ check this value and decide if the access is accepted or not...

From man system:

Code:

RETURN VALUE
       The value returned is -1 on  error  (e.g.   fork(2)  failed),  and  the
       return  status  of the command otherwise.  This latter return status is
       in the format specified in wait(2).  Thus, the exit code of the command
       will  be  WEXITSTATUS(status).   In case /bin/sh could not be executed,
       the exit status will be that of a command that does exit(127).

       If the value of command is NULL, system() returns non-zero if the shell
       is available, and zero if not.

To use WEXITSTATUS you should also

Code:

#include <sys/types.h>
#include <sys/wait.h>