fork函数的使用【学习笔记】

 1 #include "apue.h"
 2 
 3 int globvar = 6;
 4 char buf[] = "a write to stdout
";
 5 
 6 
 7 int main(void)
 8 {
 9     int var;
10     pid_t pid;
11 
12     var = 88;
13     if(write(STDOUT_FILENO,buf,sizeof(buf)-1) != sizeof(buf) -1)
14         err_sys("write error
");
15     printf("before fork
");
16 
17     if((pid = fork()) < 0){
18         err_sys("fork error");
19     }else if(pid == 0){
20         globvar++;
21         var++;
22     }else{
23         sleep(2);
24     }
25     printf("pid = %ld,glob = %d,var = %d
",(long)getpid(),globvar,var);
26 
27     exit(0);
28 }