C语言实现简单的守护进程及信号处理

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C语言实现的一个比较简单的守护进程、信号处理及具名管道与守护进程通信的例子

daemon.h

#ifndef DAEMON_H_#define DAEMON_H_void write_log(char *); void set_daemon(void);void signal_handler(int);void listen_fifo();#endif

daemon.c

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <errno.h>#include <sys/stat.h>#include <time.h>#include <fcntl.h>#include <unistd.h>#include <signal.h>#include "daemon.h"const char *filename = "/home/solariens/Documents/C/err.log";const char *fifo_path = "/home/solariens/Documents/C/fifo";void write_log(char *error) {    time_t date_time;    time(&date_time);    struct tm *date = localtime(&date_time);    int year = date->tm_year;    int month = date->tm_mon;    int day = date->tm_mday;    int hour = date->tm_hour;    int min = date->tm_min;    int sec = date->tm_sec;    char str_date[1000];    memset(str_date, 0, strlen(str_date));    sprintf(str_date, "[date:%04d-%02d-%02d %02d:%02d:%02d] [err_msg:%s] \n", year, month, day, hour, min, sec, error);    FILE *fp = fopen(filename, "a");    fwrite(str_date, 1, strlen(str_date), fp);    fclose(fp);}void set_daemon() {    pid_t pid = fork();    if (pid < 0) {        write_log(strerror(errno));        exit(0);    } else if (pid > 0) {        exit(0);    } else {        setsid();        chdir("/");        umask(0);        close(STDIN_FILENO);        close(STDOUT_FILENO);        close(STDERR_FILENO);    }}void signal_handler(int signo) {    switch(signo) {        case SIGINT :            listen_fifo();            break;    }}void listen_fifo() {    int fd = open(fifo_path, O_RDONLY);    if (fd == -1) {        write_log(strerror(errno));        exit(0);    }    char buf[1000];    memset(buf, 0, sizeof(buf));    if((read(fd, buf, sizeof(buf))) > 0) {        int len = strlen(buf);        if (buf[len - 1] == '\n') {            buf[len - 1] = 0;        }        write_log(buf);    }}

main.c

#include <stdio.h>#include <signal.h>#include <unistd.h>#include "daemon.h"int main() {    set_daemon();    signal(SIGINT, signal_handler);    while(1) {        sleep(1);    }       return 0;}

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