grep

Pages

• manpage - the current manpage
• /manpage - a nicely-formatted but old version of the grep manpage

Examples

grep text_to_find *.log

find [text_to_find] by checking all the logfiles in the current folder

grep -r text_to_find *

find [text_to_find] by checking all files in the current folder or under it

Note that you can't do e.g. grep -r [text_to_find] *.log because that will only search in folders named [something].log. The reasons for this are complicated.

Questions

• So, how do you grep for a string which contains spaces and quote characters? This is probably some standard feature of Linux Shell syntax which everyone knows, but I don't, and that's why this page needs examples.

  A: Tentatively, you can surround a string with double-quotes and escape any quotes in the search-string with the backslash character. (Single quotes do not seem to work.)

• Likewise, how do you search a group of files? Using "*.*" for FILE doesn't seem to work, and leaving the FILE argument blank tells grep to expect input from STDIN.

  A: apparently "*" by itself; see examples above

Notes

The backtick character ("`") seems to mean "insert the output of this command here" -- so if you're trying to search for a literal backtick, it needs to be escaped with "\" ("\`"). This comes up sometimes when searching for SQL phrases.

Links

• official documentation: more current than the manpage on this server
• Wikipedia