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How to run two commands from a exec call in a c program

 
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# 1  
Old 10-30-2009
How to run two commands from a exec call in a c program
Hi,

I have to run two commands one after another from a c program. How can i do this with exec system calls. i tried giving them as argument toexecv but it is not working.please help


thanks
# 2  
Old 10-30-2009
From the man page of exec(3):
Quote:
The exec() family of functions replaces the current process image with a new process image.
Means that as soon as the execv() is executed, the current process (your program) is completely replaced by the program you're starting. Any instructions left in the original program won't be executed.

If you want to just run a child process, use system(3)
# 3  
Old 10-30-2009
I cannot use system as my program is setuid prgram. Basically i am trying to run two commands which require root privilegs from a set uid program . how can i run one command and then second command using exec system calls.
# 4  
Old 10-30-2009
I'd think about why it's necessary to run that program as setuid root, and if that couldn't be accomplished by other means (eg. sudo) or by using a different approach using as few privileges as possible.

IF that isn't possible, you could simulate the system() call by using fork() and wait() (warning: the following is pseudo-code)
Code:
function my_system(command)
    pid = fork()
    if pid == 0 // child
        exec(command)
    else
        wait for pid to exit

my_system(command1);
my_system(command2);

 
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