grep
grep linux command cheatsheet by Thamizhiniyan C S
Introduction
The grep filter searches a file for a particular pattern of characters, and displays all lines that contain that pattern. The pattern that is searched in the file is referred to as the regular expression.
Important Flags
Flags | Description |
---|---|
| Does a recursive grep search for the files inside the folders(if found in the specified path for pattern search; else grep won't traverse directory for searching the pattern you specify) |
| If you're grepping recursively in a directory, this flag disables the prefixing of filenames in the results. |
| This flag won't list you the pattern only list an integer value, that how many times the pattern was found in the file/folder. |
| Specifies grep to search for the PATTERN while IGNORING the case |
| Will only list the filename instead of pattern found in it. |
| It will list the lines with their line number in the file containing the pattern. |
| This flag prints all the lines that are NOT containing the pattern |
| This flag we already read above... will consider the PATTERN as a regular expression to find the matching strings. |
| The official documentation says, it can be used to specify multiple patterns and if any string matches with the pattern(s) it will list it. |
Examples
Command | Description |
---|---|
Search for the given string in a single file | |
Checking for the given string in multiple files | |
Case insensitive search | |
Match regular expression in files | |
Checking for full words, not for sub-strings using grep -w | |
Display N lines after match | |
Display N lines before match | |
Display N lines around match | |
Searching in all files recursively using grep -r | |
Invert match using grep -v | |
Display the lines which does not matches all the given pattern | |
Counting the number of matches using grep -c | |
Display only the file names which matches the given pattern using grep -l | |
Show only the matched string | |
Show the position of match in the line | |
Show line number while displaying the output using grep -n | |
Find files with a specific keyword |
Last updated