You edited a daemon's configuration file and want the running daemon to reread it without restarting. Which signal is conventionally used?
LPIC-1 Exam 101-500, objective 103. GNU and Unix commands medium
Machine-checked — no person has signed for it. This question was read against the source cited below by an automated pass, which found no contradiction. That is a weaker claim than it sounds: the same kind of process wrote the question, so it can confirm its own mistake.
Treat it as a good draft rather than as settled fact, and read the source below before you rely on it. It is not used in mock exams here — only questions a person has signed for are.
How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Not correct SIGKILL (9)
Wrong. SIGKILL forcibly terminates the process with no handler and no cleanup — the opposite of a graceful reload.
Not correct SIGTERM (15)
Wrong. SIGTERM is the standard request to shut down. The daemon would exit, not reload.
Correct SIGHUP (1)
Correct. By convention many daemons trap SIGHUP and reload their configuration, keeping their PID and open sockets.
Not correct SIGCONT
Wrong. SIGCONT resumes a process that was stopped by SIGSTOP or SIGTSTP. It has nothing to do with configuration.
Why
SIGHUP (1) meant 'the terminal hung up', and because daemons have no terminal the signal was repurposed as 'reload your configuration'. It is a convention, not a kernel rule: a program only reloads if its author wrote a handler, so check the daemon's documentation.
Where this comes from
- Cited
- LPI exam objective 103.5
- What it says
- Common signal names and numbers and their usual meanings.
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 103 and space the ones you get wrong.
More questions on this objective
- A user starts a new terminal window in a running graphical desktop session, which launches bash as an interactive shell that is NOT a login shell. Which file in the user's home directory does bash read in that case? machine-checked
- In bash, which history expansion re-runs the entire previous command line? machine-checked
- Which bash command prints the literal five characters $USER instead of the current user name? machine-checked
- You want /opt/bin searched for executables, after all the directories already in PATH, in the current bash session and in every command started from it. Which command does that? machine-checked
- There is a passwd manual page in section 1 (the command) and another in section 5 (the /etc/passwd file format). Which command opens the section 5 page? machine-checked
- Select the TWO true statements about shell variables and the environment in bash. machine-checked