fork函数的使用【学习笔记】

#include "apue.h"

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

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\r\n");
printf("before fork\r\n");

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

exit(0);
}