Execute a list of executables

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Execute a list of executables

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#1 by (1 votes)

3

I am trying to implement a program that concurrently runs a list of executables specified as command line arguments, considering the executables without any arguments of their own. The program should wait for the end of the execution of all processes created by itself.

I can only use these functions to execute:

int execl(const char*path, const char*arg0, ..., NULL);
int execlp(const char*file, const char*arg0, ..., NULL);
int execv(const char*path, char*const argv[]);
int execvp(const char*file, char*const argv[]);

This is what I've created so far:

void main (int args , char **s) {

   int  i , x , status;

   if (args >= 2) {

    x = fork ();

    for ( i = 1 ; i < args ; i++) {

         if (x == 0) {
            execvp (s[i],&s[i]);
            x = fork();
         }
         else
         {
            wait (&status);
            _exit(i);
         }
      }
  }
   _exit(0);
}

But the program only executes the first argument of main . How can I change the code to do what I want?

c

asked by anonymous 10.03.2016 / 17:11

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         if (x == 0) {
            execvp (s[i],&s[i]);
            x = fork();          // <== nunca executa
         }

This second fork() never runs. After execvp() the current program is replaced by another one and fork() ceases to "exist".

First you do fork() . Then, only on the child, you do exec() . So you have two active processes: the parent running the original program and the child running the exec program.

// basicamente (MUITO BASICAMENTE) é isto
if (fork() == 0) {
    exec();     // o filho passa a executar outro programa
}               // o pai continua a executar este programa

There is a Wikipedia article on fork-exec .