CODEWITHSUNDEEP
cunixexecfork
Radu Stejerean
Radu Stejerean

Reputation: 345

Compile source C in a process

I want to compile a source C in a parent process and then , the executable created , I want to run it into a son process. Any ideas?

Thank you. 

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

#define execle("/bin/ls","bin/ls","-l",NULL);

int main(int argc , char **argv )
{
    int i;
    for(i=1 ; i<argc ; i++)
    {
        if(argv[1]==".c")
        {
            if(fork()==0)
            {
                execle("/usr/bin/gcc","/usr/bin/gcc",argv[1],NULL);
                exit(1);
            }    
        }

        if(argv[2]==".out")
        {
            if(fork()==0)
            {
                execle("/bin/cat","bin/cat/",argv[2],NULL);
                exit(1);
            }
        }
    } 
    return 0;
}

Here is how the code looks like , but can you tell me why it gives me errors on the lines where execle(..) is ?

Upvotes: 0

Views: 247

Answers (2)

user418748
user418748

Reputation: 

#define execle("/bin/ls","bin/ls","-l",NULL);

What do you expect this line to do ?

These two lines 

if(argv[1]==".c")
if(argv[2]==".out")

Don't do what you think

try

if( strcmp(".c" , argv[1]) == 0 )
if( strcmp(".out" , argv[2]) == 0 )

More : http://www.cplusplus.com/reference/clibrary/cstring/strcmp/

Also,

exec("/bin/cat","bin/cat/",argv[2],NULL);

Does not really exist, so change it to execle and #include <stdint.h>

More : http://www.yolinux.com/TUTORIALS/ForkExecProcesses.html

You should end up with something like :

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

int main(int argc , char **argv)
{
    int i;
    for(i=1 ; i<argc ; i++)
    {
        if(strcmp(".c" , argv[1]) == 0)
        {
            if(fork()==0)
            {
                execle("/usr/bin/gcc","/usr/bin/gcc",argv[1],NULL);
                exit(1);
            }    
        }

        if(strcmp(".c" , argv[1]) == 0)
        {
            if(fork()==0)
            {
                execle("/bin/cat","bin/cat/",argv[2],NULL);
                exit(1);
            }
        }
    } 
    return 0;
}

Upvotes: 1

Mat
Mat

Reputation: 206909

In your parent/driver program, use the system(3) call or a combination of fork/exec/wait to run your compiler. Then you can use the same calls to run the newly compiled executable.

Keep in mind the security aspects of this while implementing it. This kind of thing has a huge exploit potential.

Upvotes: 4

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