wait(null) and wait(&status) C language and Status

c unix posix wait status
user3260388 picture user3260388 · Apr 15, 2014 · Viewed 44k times · Source

What is the difference between wait(null) and wait(&status) in c system programming?

And what is the content of the pointer status ?

Answer

user43968 picture user43968 · Apr 15, 2014

If you call wait(NULL) (wait(2)), you only wait for any child to terminate. With wait(&status) you wait for a child to terminate but you want to know some information about it's termination.

You can know if the child terminate normally with WIFEXITED(status) for example.

status contains information about processes that you can check with some already defined MACRO.

Related questions

How can I convert a file pointer ( FILE* fp ) to a file descriptor (int fd)?

I have a FILE *, returned by a call to fopen(). I need to get a file descriptor from it, to make calls like fsync(fd) on it. What's the function to get a file descriptor from a file pointer?

Read More
What is the Difference Between read() and recv() , and Between send() and write()?

What is the difference between read() and recv(), and between send() and write() in socket programming in terms of performances, speed and other behaviors?

Read More
Recursive mkdir() system call on Unix

After reading the mkdir(2) man page for the Unix system call with that name, it appears that the call doesn't create intermediate directories in a path, only the last directory in the path. Is there any way (or other function) …

Read More