grep.md

grep(1)

Options

-h                                              # do not show filename
-i                                              # no case
-r                                              # recursive
-o                                              # show only mattching word of the line
-v                                              # invert match
-l                                              # display only the file names which matches the given pattern

Examples

grep -r foo .                                   # grep for 'foo' in current folder
grep -e '-X'                                    # use -e when pattern has a leading '-'
grep -v '^$' file                               # remove blank lines
ps ax | grep ssh | grep -v grep                 # list ssh processes without grep process
tail -f | grep -E 'error|'                      # colorize 'error' in tail
grep --color='auto' -P -n "[\x80-\xFF]" file    # grep for non-ASCII Characters
cat file1 | grep -f - file2                     # grep for pattern from file1 in file2
grep -o '.' file.txt | sort | uniq -c           # letter distribution of all words in file.txt