nohup for persistent processes in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the nohup command do in Linux?

The nohup command runs a process that ignores the hangup signal, so it keeps running even after you close the terminal.

beginner

How do you run a script named backup.sh persistently using nohup?

Use nohup ./backup.sh &. This runs the script in the background and keeps it running after logout.

intermediate

What file does nohup use to save output if no output file is specified?

It saves output to nohup.out in the current directory or home directory if it can't write there.

beginner

Why do we add & at the end of a nohup command?

The & puts the process in the background so you can keep using the terminal immediately.

intermediate

Can nohup keep a process running after a system reboot?

No, nohup only keeps a process running after logout or terminal close. For reboot persistence, use system services or cron jobs.

What happens if you close the terminal after running nohup myscript.sh &?

A The script keeps running in the background.

B The script stops immediately.

C The script pauses until the terminal reopens.

D The script restarts automatically.

nohup ignores hangup signals, so the script keeps running even if the terminal closes.

Where does nohup save output if you don't redirect it?

A /dev/null

B /var/log/syslog

C nohup.out file

D It discards the output

By default, nohup writes output to nohup.out in the current directory or home directory if it can't write there.

Which symbol is used to run a command in the background?

A $

B #

C *

D &

The & symbol runs a command in the background.

Does nohup guarantee a process will survive a system reboot?

A No, it only survives terminal close or logout.

B Yes, it survives reboot automatically.

C Only if combined with <code>cron</code>.

D Only if run as root.

nohup does not survive system reboots; it only ignores hangup signals from terminal close or logout.

What is the main reason to use nohup?

A To speed up a process.

B To keep a process running after logout or terminal close.

C To run a process with higher priority.

D To automatically restart a process if it crashes.

nohup is used to keep processes running after logout or terminal close by ignoring hangup signals.

Explain how to use nohup to run a script persistently and why it is useful.

Think about running a long task and closing your terminal without stopping it.

Describe the limitations of nohup regarding process persistence.

Consider what happens when the computer restarts.