Grep Quotes in Linux
Grep Quotes in Linux
Grep is your friend, and a powerful tool. This article looks at some common scenarios for grep and how it is used to address them.
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Count line when words have been matched:
$ grep -c 'word' /path/to/filePass the -n option to precede each line of output with the number of the line in the text file:
$ grep -n 'root' /etc/passwdIgnore word case:
$ grep -i 'word' /path/to/fileUse grep recursively under each directory:
$ grep -r 'word' /path/to/fileUse grep to search 2 different words:
$ egrep -w 'word1|word2' /path/to/fileGrep invert match:
$ grep -v 'word' /path/to/fileYou can force grep to display output in colors, enter:
$ grep --color 'word' /path/to/fileYou can limit the results count:
$ grep -m 10 'word' /path/to/fileYou can match regular expression in files (Syntax: grep "REGEX" filename):
$ grep 'word1.*word2' /path/to/file- ? The preceding item is optional and matched at most once.
- * The preceding item will be matched zero or more times.
- + The preceding item will be matched one or more times.
- {n} The preceding item is matched exactly n times.
- {n,} The preceding item is matched n or more times.
- {,m} The preceding item is matched at most m times.
- {n,m} The preceding item is matched at least n times, but not more than m times.
Display N lines Around Match
Grep can display N lines after match (Syntax: grep -A <N> "string" filename):
$ grep -A 2 'word' /path/to/fileThe following example prints the matched line, along with the two lines after it.
$ grep -A 2 -i 'word' /path/to/file-C is the option which prints the specified N lines before the match.
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