how to execute shell script with c code?

khucinx · 05-04-2004, 07:09 AM

i have built c code (in a file coba.c) just like this :
#include<unistd.h>
int main()
{
char *apa="test";
int i;
i=execv("cobi",apa);
return 0;
}

and i have built shell script in the same directory with coba.c like this (name is cobi):
#!/bin/sh
echo $apa

i hope, the output is "test" in terminal by execute coba like ./coba. but there are no output. any body help me, please?

jim mcnamara · 05-04-2004, 10:14 AM

try:

Code:

#include <stdlib.h>
int main()
{
  char *apa="test";
  char tmp[256]={'\0'};
  sprintf(tmp,"./cobi '%s'",apa);
  system(tmp);  
  return 0;
}

Code:

#!/bin/sh  
echo "in cobi"
echo $1
exit 0

dsheller · 05-04-2004, 03:41 PM

Really off topic, but this answered my question, partially. Wanted to know how to do it in c++, but guess this will work too. Another question though, once you run it, is there a way you can get its process ID and put that in a file? Also, jim don't you also goto vbforums?

jim mcnamara · 05-04-2004, 03:54 PM

Yes, I post at VBF.

You can call fork() and execlp(), for example, to run a script and get it's return status. This invokes the POSIX shell in a child process. Getting return values are not straightforward. You need to read the man page for execlp. fork() returns a pid

Code:

pid_t pid;
pid=fork();
if (pid == 0 ){
 /* you are in the child process*/
     execlp(something or other);
}else{
/* you are still in the parent process */
    printf("child pid=%d\n",pid);
}

system() provides a wrapper for this. It does return the exit status of the command interpreter it invokes, but the status is returned the way wait() returns a status.