38 lines
1.3 KiB
C
38 lines
1.3 KiB
C
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// Demonstrate the basics of fork/exec to launch a child process to do
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// "labor".
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/wait.h>
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#include <unistd.h>
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int main(int argc, char* argv){
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char *child_argv[] = {"ls","-l","-ah",NULL}; // argument array to child, must end with NULL
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char *child_cmd = "ls"; // actual command to run, must be on path
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printf("I'm %d, and I really don't feel like '%s'ing\n",
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getpid(),child_cmd); // use of getpid() to get current PID
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printf("I have a solution\n");
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pid_t child_pid = fork(); // clone a child
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// wait(NULL);
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if(child_pid == 0){ // child will have a 0 here
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printf(" I'm %d My pa '%d' wants me to '%s'. This sucks.\n",
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getpid(), getppid(), child_cmd); // use of getpid() and getppid()
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execvp(child_cmd, child_argv); // replace running image with child_cmd
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printf(" I don't feel like myself anymore...\n"); // unreachable statement
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}
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else{ // parent will see nonzero in child_pid
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int status;
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wait(&status);
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// waitpid(child_pid, NULL, 0);
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printf("Great, junior %d is taking care of that\n",
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child_pid);
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}
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return 0;
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}
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