怎样利用shell检查main的返回值

harrytina

apue上说，可以利用shell检查程序的返回值，但我不知道怎样实现。谁能解释一下，谢谢。

_z_

after the process's exiting,
use "echo $?" to print the return value.

_z_

fork a child and invoke "system" to excute your program.
in the parent process,invoke "wait" or "waitpid" to get the "status".

/* pid_t wait(int * status) ;  pid_t waitpid(pid_t pid,int * status,int options); */

last,use macro "WIFEXITED(status)" to get the value.

you can find these in APUE.