sudo find / -name "*" | xargs grep -sn --color=auto "-j"
Above command returns below:
grep: invalid option -- 'j'
Usage: grep [OPTION]... PATTERN [FILE]...
Try `grep --help' for more information.
...
How do I search for string -j?
In your case "-j" is interpreted by grep as an argument/option, not as a search pattern, even if you quoted it. To make it to be the pattern for what you want to search, just use -eoption:
sudo find / -name "*" | xargs grep -sn --color=auto -e "-j"
or even:
sudo find / -name "*" | xargs grep -sn --color=auto -e -j
The -e argument/option means that the next argument is the pattern. This is from man grep:
-e PATTERN, --regexp=PATTERN
Use PATTERN as the pattern. This can be used to specify
multiple search patterns, or to protect a pattern beginning with
a hyphen (-). (-e is specified by POSIX.)
Other ways:
use --, as @Rinzwind said in his answer, to make grep to hnow that the options ended.
use to escape the hyphen (-):
sudo find / -name "*" | xargs grep -sn --color=auto "-j"
