Find and replace text in source files
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Find and replace text in source files.

ruplacer screenshot

Installing with cargo

Install rust and cargo, for example with rustup.

Then run:

cargo install ruplacer

Alternative installation methods

  • Pre-compiled binaries for Linux, macOS, and Windows are available as assests of the latest release.

  • ruplacer can also be installed from homebrew:

$ brew install TankerHQ/homebrew-repo/ruplacer

Basic usage

ruplacer pattern replacement [path]

If the path is not given, it defaults to the current working directory.

Ruplacer will then walk through every file in <path> while honoring .gitignore files found on the way.

Binary files and text files containing non-UTF8 characters will be skipped. Then for every remaining file, it will read the contents, replace all lines matching the pattern by the replacement, and print the difference:

$ replacer old new src/
Patching src/a_dir/sub/foo.txt
-- old is everywhere, old is old
++ new is everywhere, new is new

Patching src/top.txt
-- old is nice
++ new is nice

If you are OK with the replacements, re-run ruplacer with the --go option to actually write the files.


By default, pattern will be compiled into a Rust regex.

Note that it's slightly different from Perl-style regular expressions. Also, you must use $1, $2 to reference groups captured from pattern inside replacement.

For instance, this replaces 'last, first' by 'first last':

$ ruplacer '(\w)+, (\w)+' '$2 $1'

(note the use of single quotes to avoid any processing by the shell)

If you don't want the pattern to be used as a regex, use the --no-regex command line flag.

This makes it possible to look for special characters without escaping them:

# This is a regex that matches the letter a
# or the letter o
$ ruplacer '(a|o)' u
- tata toto
+ tutu tutu
- (a|o)
+ (u|u)

# This is the literal string: '(a|o)'
$ ruplacer --no-regex '(a|o)' u
# or
$ ruplacer '\(a\|o|)' u
- (a|o)
+ u

Subvert mode

Ruplacer has a --subvert option which works across a variety of case styles (lower case, snake case, and so on):

$ ruplacer --subvert foo_bar spam_eggs
Patching src/foo.txt
-- foo_bar, FooBar, and FOO_BAR!
++ spam_eggs, SpamEggs, and SPAM_EGGS!

Filter files by type

Inspired by ripgrep, you can also select or ignore certain "file types":

# Select only C++ files
$ ruplacer old new --type cpp
# Ignore all js files
$ ruplacer old new --type-ignore js

Each "file type" is just a list of glob pattern. For instance: the cpp file type matches *.C, *.H, *.cc, *.cpp and so on ...

You can see the whole list by using ruplacer --file-types.