Here are the explanations and examples of the commands
you've mentioned:
- ps: The ps command (short for process
status) is used to provide information about the currently running
processes, including their process identification numbers (PIDs).
Example usage: ps -ef will display all the currently
running processes in the system.
- wait: The wait command is used in
shell scripting primarily. When run, it causes the script or the shell to
wait for all background jobs or specified JobID/PIDs to terminate before
resuming execution.
Example usage: wait %1 will cause the shell to wait
for the completion of the job with JobID 1.
- sleep: The sleep command is used to
create a dummy job during scripting. A dummy job helps in delaying the
execution.
Example usage: sleep 10 will halt the execution of
the next command for 10 seconds.
- exit: The exit command is used to end
the shell where it is currently running. It makes the shell exit, and if
the shell is a login shell, then it terminates the login session.
Example usage: exit will terminate the shell.
- kill: The kill command is used to
send a signal to a process. By default, it sends a TERM (terminate) signal
to the specified process.
Example usage: kill 12345 will send the TERM signal
to the process with PID 12345. If the process doesn't terminate, a stronger
KILL signal can be sent with kill -9 12345.
Remember, these commands are typically used in Unix-like
operating systems, including Linux distributions. The exact details or options
might vary between different systems. Be sure to consult the man pages (man
<command>) in your system for the exact usage details.