Use of exec command in linux bash shell

In this article we will look at the usage of exec command in linux.

exec overrides the parent process and replaces it.

Lets see an example to understand exec command usage.

Usage of exec Command

### Check current process id.
[root@ngelinux ~]# ps $$
  PID TTY      STAT   TIME COMMAND
 5184 pts/1    Ss     0:00 -bash


### Run a command with exec
### It will now replace the new process with current process.
### As a result, our bash pid is overridden and killed by new process.

[root@ngelinux ~]# exec echo "hello how are you"
hello how are you
Connection closing...Socket close.

Connection closed by foreign host.

Disconnected from remote host(nglinux) at 15:06:57.

Similarly in shell scripts, exec replaces the parent process and can run independently.

Tags: bashexeclinuxoverridesparentparent processprocessshellunix