30 lines
		
	
	
		
			766 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			30 lines
		
	
	
		
			766 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | title: Bash Grep | ||
|  | --- | ||
|  |  ## Bash command: grep | ||
|  |  `grep` stands for Global Regular Expression Print. It is used to search piped input or files for a string which can contain regex. | ||
|  |   | ||
|  |  ### Usage | ||
|  |  ``` | ||
|  |  grep <some string> <file name> | ||
|  |  ``` | ||
|  |   | ||
|  |  Commonly used options: | ||
|  |  * `-i` - Ignores the case when performing the search. | ||
|  |  * `-v` - Inverts the search and only selects lines that do not match the search string. | ||
|  |   | ||
|  |  ### Examples | ||
|  |  #### Search for IP 127.0.0.1 in the /etc/hosts file | ||
|  |  ```bash | ||
|  |  grep "127.0.0.1" /etc/hosts | ||
|  |  ``` | ||
|  |   | ||
|  |  #### Search for oom (out of memory) in /var/log/messages | ||
|  |  ```bash | ||
|  |  grep -i oom /var/log/messages | ||
|  |  ``` | ||
|  |   | ||
|  |  ### More Information | ||
|  |  * run `man grep` for a full list of available flags/options to use. | ||
|  |  * [Wikipedia](https://en.wikipedia.org/wiki/Grep) |