What cat … | grep does
cat log.txt | grep error: Feed a file's contents into grep through a pipe.
The cat command page covers what it does in general, with an example.
catlog.txt|greperror
cat— command — print a file's contentslog.txt— argument: a file, a folder, or text|— pipe: the previous command's output becomes the next one's inputgrep— command — find lines matching a patternerror— argument: a file, a folder, or text
What it does when you run it
$ cat log.txt | grep error
error: disk full
error: retry
Run it yourself
The same files. Nothing here can break, and nothing leaves your browser.
Where you use it
Explain other commands
Written by Mikhail Kuzmitskii