18. Text processing tool -grep

grep

For text search , Print matching lines

Pattern ： Filter conditions written by regular expression characters and text characters

Format   grep [option] pattern [file]...

Common options

--color=auto  Color the matched text

-m # matching # Stop after

-v Display not pattern Matched rows

-i Ignore character case

-n Show matching line numbers

-c Count matching rows

-o Show only strings that match

-q silent mode , Do not output any information

-A # after, after # That's ok

-B # before, front # That's ok

-c # context, Before and after # That's ok

-e Implement logic between multiple options or Relationship

-w Match the whole word

-E Use ere, amount to egrep（ Extended regularization ）

-F Regular expressions are not supported , amount to fgrep

-f file Process according to the schema file

-r Recursive directory , But don't handle soft links

-R Recursive directory , But dealing with soft links