How do erase the contents of a error.log file but keep the file intact

ubuntu logging nginx

46,610

Solution 1

You can use this:

>error.log

(typed just like that - an empty output redirection)

truncate -s0 error.log

You'll confuse the daemon. Erase the file then send SIGHUP to nginx.

46,610

Updated on September 17, 2022

user27449 almost 2 years

I want to erase the contents of the file error.log (nginx error log file), but I don't want to actually delete the file.

is this possible?

running ubuntu
Ignacio Vazquez-Abrams over 13 years

If you wanted to, sure. But that would disrupt service.
Dennis Williamson over 13 years

@Ignacio: If the file already exists, either will truncate it. If the file doesn't exist, either will create it.
Ignacio Vazquez-Abrams over 13 years

You're right, my bad.
Dennis Williamson over 13 years

I think both a null redirection and a truncate are atomic, so as long as no seeking is going on (especially if the only operation that's occurring is appending) it shouldn't be disruptive.
davidkonrad about 10 years

The last option worked for me, for some reason sudo >error.log didnt work for me (ubuntu 12.04)
davidkonrad about 10 years

OK, didnt knew that. Thank you for clarification!
divHelper11 over 5 years

The first one worked for me perfectly! Even though I dont understand what it does :D Thank you
Dennis Williamson over 5 years

@divHelper11: In my answer I say it's an "empty output redirection". That means that "nothing" is being sent to the named file and that overwrites any existing contents. It's similar to echo "some words" > output.txt but nothing is going in.