How to echo shell commands as they are executed?

In a shell script, how do I echo all shell commands called and expand any variable names? For example, given the fo...

How to echo shell commands as they are executed?

In a shell script, how do I echo all shell commands called and expand any variable names? For example, given the fo...

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

What is the difference between wait(null) and wait(&status) in c system programming? And what is the content of...

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 p...

How to make parent wait for all child processes to finish??

I'm hoping someone could shed some light on how to make the parent wait for ALL child processes to finish before con...

What is the difference between /etc/environment and /etc/profile??

I understand that the former is loaded prior to the latter, but what is the conceptual difference? Are there any goo...