43 lines
1.4 KiB
C
43 lines
1.4 KiB
C
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// fork/exec plus parent waits for child and sees their status
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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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char *child_argv[] = {"./complain",NULL}; // alternative commands
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char *child_cmd = "complain";
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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);
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printf("I have a solution\n");
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pid_t child_pid = fork();
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if(child_pid == 0){
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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);
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execvp(child_cmd, child_argv);
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printf(" I don't feel like myself anymore...\n"); // unreachable
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}
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else{
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int status;
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wait(&status); // wait for child to finish, collect status
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if(WIFEXITED(status)){
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int retval = WEXITSTATUS(status); // decode status to 0-255
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printf("Great, junior %d did that and told me '%d'\n",
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child_pid, retval);
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if(retval != 0){ // nonzero exit codes usually indicate failure
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printf("That little punk gave me a non-zero return. I'm glad he's dead\n");
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}
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}
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}
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return 0;
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}
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