# string-replace - replace substrings

## Synopsis

    string replace [(-a | --all)] [(-f | --filter)] [(-i | --ignore-case)] [(-r | --regex)] [(-q | --quiet)] PATTERN REPLACEMENT [STRING...]

## Description

`string replace` is similar to `string match` but replaces non-overlapping matching substrings with a replacement string and prints the result. By default, PATTERN is treated as a literal substring to be matched.

If `-r` or `--regex` is given, PATTERN is interpreted as a Perl-compatible regular expression, and REPLACEMENT can contain C-style escape sequences like `\t` as well as references to capturing groups by number or name as `$n` or `${n}`.

If you specify the `-f` or `--filter` flag then each input string is printed only if a replacement was done. This is useful where you would otherwise use this idiom: `a_cmd | string match pattern | string replace pattern new_pattern`. You can instead just write `a_cmd | string replace --filter pattern new_pattern`.

Exit status: 0 if at least one replacement was performed, or 1 otherwise.

## Examples

### Replace Literal Examples

    >_ string replace is was 'blue is my favorite'
    blue was my favorite

    >_ string replace 3rd last 1st 2nd 3rd
    1st
    2nd
    last

    >_ string replace -a ' ' _ 'spaces to underscores'
    spaces_to_underscores

### Replace Regex Examples

    >_ string replace -r -a '[^\d.]+' ' ' '0 one two 3.14 four 5x'
    0 3.14 5

    >_ string replace -r '(\w+)\s+(\w+)' '$2 $1 $$' 'left right'
    right left $

    >_ string replace -r '\s*newline\s*' '\n' 'put a newline here'
    put a
    here