nohup
Processes and system
Usage
nohup <command> [args] &Makes a command ignore the hangup signal so it survives logout; it does not background anything, so you still add `&` yourself, and output piles up quietly in ./nohup.out.
Common flags
| Flag | Meaning |
|---|---|
| & | You add this yourself: nohup alone does not put the command in the background. |
| > out.log 2>&1 | Send output somewhere other than the default ./nohup.out. |
| < /dev/null | Detach stdin as well, so the command cannot stall waiting for input. |
Examples
nohup ./server.sh > server.log 2>&1 &Start the server so it survives logout, with its own log file.
nohup make -j4 &Run a long build that keeps going after you disconnect; output lands in nohup.out.
What is running and what is eating the machine. Identifying it comes before killing it.
How to read this
- Square brackets [ ] mark a part you may leave out.
- An ellipsis … means you can list more than one.
- Flags are case-sensitive — in some commands -r and -R do different things.
Questions
Q. What does nohup do?
Makes a command ignore the hangup signal so it survives logout; it does not background anything, so you still add `&` yourself, and output piles up quietly in ./nohup.out.
Q. How do I type it?
nohup <command> [args] & — square brackets mark the parts you can leave out.
Q. How many flags are worth knowing?
3 are listed here; the full set is in man nohup. This command sits under Processes and system.
Related commands
man page: man nohup