What happens in background?

[packet]

Hello All,


I am doing some basic stuffs on the terminal can any one tell me that How exactly the ls command works ?

Q1 : The exact question is what happens in the background when we type a command ls or some other commands on the terminal ?













Thnaks,

Packet

[GNU-Fan]

Assuming ls is neither a builtin or a declared function in the shell:

- The shell looks if it can find an executable called "ls" in the directories which are in the PATH variable.

- Shell tells the kernel to load this executable into memory and to execute it, passing it the options you typed after "ls". For example "-a".

What ls exactly does you find out by typing "man ls" and by looking at the programs source code. "ls" is part of the GNU coreutils Index of /pub/gnu/coreutils

[Lakshmipathi]

In case if you looking from programming point of view,use strace ls, it will show you list of system call executed to produce the desired result.

[CSMG Sarma]

when you type a command in the shell, let us say "ls" in this case, shell "forks" a child process which "exec"s "ls". This is how shell works.

Hope this was helpful.
Sarma

[packet]

Thanks lot for everyone