38 lines
1,016 B
C
38 lines
1,016 B
C
// demonstrate non-blocking waitpid()
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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[] = {"./complain",NULL}; // alternative commands
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char *child_cmd = "complain";
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printf("PARENT: Junior is about to '%s', I'll keep an eye on him\n",
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child_cmd);
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pid_t child_pid = fork();
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// CHILD CODE
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if(child_pid == 0){
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printf("CHILD: I'm %d and I'm about to '%s'\n",
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getpid(), child_cmd);
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execvp(child_cmd, child_argv);
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}
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// PARENT CODE
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int status;
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int pid = waitpid(child_pid,&status,WNOHANG); // Check if child done, but don't actually wait
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if(pid == child_pid && WIFEXITED(status)){ // Child did finish
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printf("PARENT: Good job junior. You told me %d\n",WEXITSTATUS(status));
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return 0;
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}
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else{ // Child not done yet
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printf("PARENT: %d? The kid's not done yet. I'm bored\n",pid);
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return -1;
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}
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return 0;
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}
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