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slim-sprig

Useful template functions for Go templates.

String Functions

Sprig has a number of string manipulation functions.

trim

The trim function removes space from either side of a string:

trim "   hello    "

The above produces hello

trimAll

Remove given characters from the front or back of a string:

trimAll "$" "$5.00"

The above returns 5.00 (as a string).

trimSuffix

Trim just the suffix from a string:

trimSuffix "-" "hello-"

The above returns hello

trimPrefix

Trim just the prefix from a string:

trimPrefix "-" "-hello"

The above returns hello

upper

Convert the entire string to uppercase:

upper "hello"

The above returns HELLO

lower

Convert the entire string to lowercase:

lower "HELLO"

The above returns hello

title

Convert to title case:

title "hello world"

The above returns Hello World

repeat

Repeat a string multiple times:

repeat 3 "hello"

The above returns hellohellohello

substr

Get a substring from a string. It takes three parameters:

substr 0 5 "hello world"

The above returns hello

trunc

Truncate a string (and add no suffix)

trunc 5 "hello world"

The above produces hello.

trunc -5 "hello world"

The above produces world.

contains

Test to see if one string is contained inside of another:

contains "cat" "catch"

The above returns true because catch contains cat.

hasPrefix and hasSuffix

The hasPrefix and hasSuffix functions test whether a string has a given prefix or suffix:

hasPrefix "cat" "catch"

The above returns true because catch has the prefix cat.

quote and squote

These functions wrap a string in double quotes (quote) or single quotes (squote).

cat

The cat function concatenates multiple strings together into one, separating them with spaces:

cat "hello" "beautiful" "world"

The above produces hello beautiful world

indent

The indent function indents every line in a given string to the specified indent width. This is useful when aligning multi-line strings:

indent 4 $lots_of_text

The above will indent every line of text by 4 space characters.

nindent

The nindent function is the same as the indent function, but prepends a new line to the beginning of the string.

nindent 4 $lots_of_text

The above will indent every line of text by 4 space characters and add a new line to the beginning.

replace

Perform simple string replacement.

It takes three arguments:

"I Am Henry VIII" | replace " " "-"

The above will produce I-Am-Henry-VIII

plural

Pluralize a string.

len $fish | plural "one anchovy" "many anchovies"

In the above, if the length of the string is 1, the first argument will be printed (one anchovy). Otherwise, the second argument will be printed (many anchovies).

The arguments are:

NOTE: Sprig does not currently support languages with more complex pluralization rules. And 0 is considered a plural because the English language treats it as such (zero anchovies). The Sprig developers are working on a solution for better internationalization.

regexMatch, mustRegexMatch

Returns true if the input string contains any match of the regular expression.

regexMatch "^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$" "test@acme.com"

The above produces true

regexMatch panics if there is a problem and mustRegexMatch returns an error to the template engine if there is a problem.

regexFindAll, mustRegexFindAll

Returns a slice of all matches of the regular expression in the input string. The last parameter n determines the number of substrings to return, where -1 means return all matches

regexFindAll "[2,4,6,8]" "123456789" -1

The above produces [2 4 6 8]

regexFindAll panics if there is a problem and mustRegexFindAll returns an error to the template engine if there is a problem.

regexFind, mustRegexFind

Return the first (left most) match of the regular expression in the input string

regexFind "[a-zA-Z][1-9]" "abcd1234"

The above produces d1

regexFind panics if there is a problem and mustRegexFind returns an error to the template engine if there is a problem.

regexReplaceAll, mustRegexReplaceAll

Returns a copy of the input string, replacing matches of the Regexp with the replacement string replacement. Inside string replacement, $ signs are interpreted as in Expand, so for instance $1 represents the text of the first submatch

regexReplaceAll "a(x*)b" "-ab-axxb-" "${1}W"

The above produces -W-xxW-

regexReplaceAll panics if there is a problem and mustRegexReplaceAll returns an error to the template engine if there is a problem.

regexReplaceAllLiteral, mustRegexReplaceAllLiteral

Returns a copy of the input string, replacing matches of the Regexp with the replacement string replacement The replacement string is substituted directly, without using Expand

regexReplaceAllLiteral "a(x*)b" "-ab-axxb-" "${1}"

The above produces -${1}-${1}-

regexReplaceAllLiteral panics if there is a problem and mustRegexReplaceAllLiteral returns an error to the template engine if there is a problem.

regexSplit, mustRegexSplit

Slices the input string into substrings separated by the expression and returns a slice of the substrings between those expression matches. The last parameter n determines the number of substrings to return, where -1 means return all matches

regexSplit "z+" "pizza" -1

The above produces [pi a]

regexSplit panics if there is a problem and mustRegexSplit returns an error to the template engine if there is a problem.

regexQuoteMeta

Returns a string that escapes all regular expression metacharacters inside the argument text; the returned string is a regular expression matching the literal text.

regexQuoteMeta "1.2.3"

The above produces 1\.2\.3

See Also…

The Conversion Functions contain functions for converting strings. The String Slice Functions contains functions for working with an array of strings.