fork函数的使用【学习笔记】

#include "apue.h"

int globvar = 6;
char buf[] = "a write to stdout
";


int main(void)
{
    int var;
    pid_t pid;

    var = 88;
    if(write(STDOUT_FILENO,buf,sizeof(buf)-1) != sizeof(buf) -1)
        err_sys("write error
");
    printf("before fork
");

    if((pid = fork()) < 0){
        err_sys("fork error");
    }else if(pid == 0){
        globvar++;
        var++;
    }else{
        sleep(2);
    }
    printf("pid = %ld,glob = %d,var = %d
",(long)getpid(),globvar,var);

    exit(0);
}