grep

Updated: 23 February 2025

Find all occurrences of foo in directories and files recursively, from the current directory

# -i: case insensitive
# -r: recursive but don't follow symlinks
# -n: show line number
# --text: treat binary files as text

grep -irn --exclude-dir=dir --text foo *

Interpret PATTERNS as --fixed-strings, not regular expressions

grep -F './dir/dir2' file.txt

Read-in a long regex, from a file

cat grep-me.log | grep --file=long-regex.txt

Word boundary

Search for the whole word 96730

grep "\<96730\>" app.log

Multiple patterns

Search for several patterns at once

grep 'pattern1\|pattern2\|pattern3' log.txt

Surrounding context

Find tell in trans.sql and show 3 lines of context surrounding the result

grep -C 3 tell trans.sql

Show 3 context lines before and 2 lines after matches

grep -B 3 -A 2 bar index.php

Show --only-matching parts of the matching line

grep -o foo index.php