57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <err.h>
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int fibo (int n){
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if (n <= 0) return 0;
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else if (n <= 1) return 1;
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else return fibo(n - 1) + fibo(n - 2);
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}
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int wait_child(int x){
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if(x < 0) return -1;
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int wstatus;
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pid_t pid = fork();
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if(pid < 0) return -1;
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// Child
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else if (pid == 0) {
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exit(fibo(x));
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}
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// Daddy
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else {
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if(waitpid(pid, &wstatus, 0) == -1) return -1;
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if(wstatus == -1) return -1;
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if (WIFEXITED(wstatus)){
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int rslt = WEXITSTATUS(wstatus);
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if (rslt == 255) rslt = -1;
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printf("My child knows how to count the Fibonacci sequence. He found %i for %i!\n",rslt, x);
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}
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return 0;
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}
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}
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/*
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int main(){
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int res = wait_child(-1);
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printf("%d\n", res); // -1
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res = wait_child(7); // 13
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printf("%d\n", res); // 0
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}*/
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