✏️ Pattern

Pattern is a string describing how to generate output from an input.

Use --explain flag to print detailed explanation what a certain pattern does.

rew --explain 'file_{c|<3:0}.{e}'

Syntax

By default, pattern characters are directly copied to output.

Input	Pattern	Output
(any)	abc	abc

Characters { and } form an expression which is evaluated and replaced in output. Empty expression {} evaluates directly to input value.

Input	Pattern	Output
world	{}	world
world	Hello, {}!	Hello, world!

Expression may contain one or more filters, separated by |. Filters are consecutively applied on input value.

Input	Pattern	Output	Description
old.JPEG	new.{e}	new.JPEG	Extension
old.JPEG	new.{e|l}	new.jpeg	Extension, Lowercase
old.JPEG	new.{e|l|r:e}	new.jpg	Extension, Lowercase, Remove e

Use -q, --quote flag to automatically wrap output of every expression in quotes.

echo abc | rew {}     # Will print  abc
echo abc | rew {} -q  # Will print 'abc'
echo abc | rew {} -qq # Will print "abc"

Escaping

Character % starts an escape sequence.

Sequence	Description
%/	System directory separator \ on Windows / everywhere else
%n	Line feed
%r	Carriage return
%t	Horizontal tab
%0	Null
%{	Escaped {
%|	Escaped |
%}	Escaped {
%%	Escaped %

Use --escape option to set a different escape character.

rew '{R:%t: }'              # Replace tabs with spaces
rew '{R:\t: }' --escape='\' # The same thing, different escape character