regexp functions

These functions allow user you to search and modify text with regular expressions.

The syntax of the regular expressions accepted is Go’s regexp syntax, and is the same general syntax used by Perl, Python, and other languages.

regexp.Find

Returns a string holding the text of the leftmost match in input of the regular expression expression.

This function provides the same behaviour as Go’s regexp.FindString function.

Added in gomplate v3.1.0

Usage

regexp.Find expression input

input | regexp.Find expression

Arguments

Examples

$ gomplate -i '{{ regexp.Find "[a-z]{3}" "foobar"}}'
foo

$ gomplate -i 'no {{ "will not match" | regexp.Find "[0-9]" }}numbers'
no numbers

regexp.FindAll

Returns a list of all successive matches of the regular expression.

This can be called with 2 or 3 arguments. When called with 2 arguments, the n argument (number of matches) will be set to -1, causing all matches to be returned.

This function provides the same behaviour as Go’s regexp.FindAllString function.

Added in gomplate v3.1.0

Usage

regexp.FindAll expression [n] input

input | regexp.FindAll expression [n]

Arguments

Examples

$ gomplate -i '{{ regexp.FindAll "[a-z]{3}" "foobar" | toJSON}}'
["foo", "bar"]

$ gomplate -i '{{ "foo bar baz qux" | regexp.FindAll "[a-z]{3}" 3 | toJSON}}'
["foo", "bar", "baz"]

regexp.Match

Returns true if a given regular expression matches a given input.

This returns a boolean which can be used in an if condition, for example.

Added in gomplate v1.9.0

Usage

regexp.Match expression input

input | regexp.Match expression

Arguments

Examples

$ gomplate -i '{{ $u := env.Env.USER }}{{if ($u | regexp.Match `^h`) }}username ({{ $u }}) starts with h!{{end}}'
username (hairyhenderson) starts with h!

regexp.QuoteMeta

Escapes all regular expression metacharacters in the input. The returned string is a regular expression matching the literal text.

This function provides the same behaviour as Go’s regexp.QuoteMeta function.

Added in gomplate v3.7.0

Usage

regexp.QuoteMeta input

input | regexp.QuoteMeta

Arguments

Examples

$ gomplate -i '{{ `{hello}` | regexp.QuoteMeta }}'
\{hello\}

regexp.Replace

Replaces matches of a regular expression with the replacement string.

The replacement is substituted after expanding variables beginning with $.

This function provides the same behaviour as Go’s regexp.ReplaceAllString function.

Added in gomplate v1.9.0

Usage

regexp.Replace expression replacement input

input | regexp.Replace expression replacement

Arguments

Examples

$ gomplate -i '{{ regexp.Replace "(foo)bar" "$1" "foobar"}}'
foo

$ gomplate -i '{{ regexp.Replace "(?P<first>[a-zA-Z]+) (?P<last>[a-zA-Z]+)" "${last}, ${first}" "Alan Turing"}}'
Turing, Alan

regexp.ReplaceLiteral

Replaces matches of a regular expression with the replacement string.

The replacement is substituted directly, without expanding variables beginning with $.

This function provides the same behaviour as Go’s regexp.ReplaceAllLiteralString function.

Added in gomplate v3.1.0

Usage

regexp.ReplaceLiteral expression replacement input

input | regexp.ReplaceLiteral expression replacement

Arguments

Examples

$ gomplate -i '{{ regexp.ReplaceLiteral "(foo)bar" "$1" "foobar"}}'
$1

$ gomplate -i '{{ `foo.bar,baz` | regexp.ReplaceLiteral `\W` `$` }}'
foo$bar$baz

regexp.Split

Splits input into sub-strings, separated by the expression.

This can be called with 2 or 3 arguments. When called with 2 arguments, the n argument (number of matches) will be set to -1, causing all sub-strings to be returned.

This is equivalent to strings.SplitN, except that regular expressions are supported.

This function provides the same behaviour as Go’s regexp.Split function.

Added in gomplate v3.1.0

Usage

regexp.Split expression [n] input

input | regexp.Split expression [n]

Arguments

Examples

$ gomplate -i '{{ regexp.Split `[\s,.]` "foo bar,baz.qux" | toJSON}}'
["foo","bar","baz","qux"]

$ gomplate -i '{{ "foo bar.baz,qux" | regexp.Split `[\s,.]` 3 | toJSON}}'
["foo","bar","baz"]