grep command
grep --color=auto -rns "hello world" *grep command : grep (Globally search a Regular Expression and Print) for filtering / searching the specific character. Regular expressions can be used in conjunction with a variety of command
The string to look : If the search string contains spaces, caused by the need to single and double quotation marks can be used
* : All files in the current directory, you can also write specific directory or file name
Return result : The result is returned in the console, if used in a script, you can search through a successful return 0, 1 search fails to return, file search does not exist, the judge returns 2
Parameters :
-r is this same recursive search -R
-n query result display line numbers
-i ignore case
-s does not display an error message
-w matches whole words only, and not part of the string
The number 'search string' -c statistics of each line found (when there -c -n failure)
-V displays all lines do not contain matching text, reverse lookup
-l and -L option to display only the matching / non-matching file names
L n have the time and the conflict can only display matching file names
-H output file name -h hidden file name
--color = auto query string can be displayed using different colors
