53 lines
959 B
C
53 lines
959 B
C
/*
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* SPDX-License-Identifier: MIT
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* Copyright (c) 2025 Fabio Scotto di Santolo
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*/
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#define NR_OPEN 1048576
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int main(void)
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{
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// create new process
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pid_t pid = fork();
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if (pid == -1) {
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return -1;
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} else if (pid != 0) {
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printf("Running daemon with pid %d\n", pid);
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exit(EXIT_SUCCESS);
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}
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// create a new session and process group
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if (setsid() == -1)
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return -1;
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// set the working directory to the root directory
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if (chdir("/") == -1)
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return -1;
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// close all open files--NR_OPEN is overkill, but works
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for (int i = 0; i < NR_OPEN; i++) {
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close(i);
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}
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// redirect fd's 0,1,2 to /dev/null
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open("/dev/null", O_RDWR); // stdin
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dup(0); // stdout
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dup(0); // stderr
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// do its daemon thing
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for (int i = 0; i < 10; i++) {
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printf("Hello from daemon %d\n", getpid());
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sleep(1000);
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}
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return 0;
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}
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