5.27

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <syslog.h>
#include <signal.h>
                                                                                                                             
#define MAXFD 64
                                                                                                                             
void
daemon_init(const char * pname, char *workdir)
{
        int     i;
        pid_t   pid;
                                                                                                                             
        if((pid = fork()) != 0)
                exit(0);
        setsid();
        signal(SIGHUP, SIG_IGN);
        if((pid = fork()) != 0)
                exit(0);
        chdir(workdir);
        umask(0);
        for(i = 0; i < MAXFD; i++)
                close(i);
}
本来chdir（）是这样用的：chadir（“/"），发现工作目录改到根目录，改成工作目录就可以了。