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atlantis/vendor/github.com/Masterminds/sprig/docs/strings.md
2018-06-19 21:10:07 +01:00

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# 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`
## 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`
## untitle
Remove title casing. `untitle "Hello World"` produces `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:
- start (int)
- length (int)
- string (string)
```
substr 0 5 "hello world"
```
The above returns `hello`
## nospace
Remove all whitespace from a string.
```
nospace "hello w o r l d"
```
The above returns `helloworld`
## trunc
Truncate a string (and add no suffix)
```
trunc 5 "hello world"
```
The above produces `hello`.
## abbrev
Truncate a string with ellipses (`...`)
Parameters:
- max length
- the string
```
abbrev 5 "hello world"
```
The above returns `he...`, since it counts the width of the ellipses against the
maximum length.
## abbrevboth
Abbreviate both sides:
```
abbrevboth 5 10 "1234 5678 9123"
```
the above produces `...5678...`
It takes:
- left offset
- max length
- the string
## initials
Given multiple words, take the first letter of each word and combine.
```
initials "First Try"
```
The above returns `FT`
## randAlphaNum, randAlpha, randNumeric, and randAscii
These four functions generate random strings, but with different base character
sets:
- `randAlphaNum` uses `0-9a-zA-Z`
- `randAlpha` uses `a-zA-Z`
- `randNumeric` uses `0-9`
- `randAscii` uses all printable ASCII characters
Each of them takes one parameter: the integer length of the string.
```
randNumeric 3
```
The above will produce a random string with three digits.
## wrap
Wrap text at a given column count:
```
wrap 80 $someText
```
The above will wrap the string in `$someText` at 80 columns.
## wrapWith
`wrapWith` works as `wrap`, but lets you specify the string to wrap with.
(`wrap` uses `\n`)
```
wrapWith 5 "\t" "Hello World"
```
The above produces `hello world` (where the whitespace is an ASCII tab
character)
## 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:
- string to replace
- string to replace with
- source string
```
"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:
- singular string
- plural string
- length integer
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.
## snakecase
Convert string from camelCase to snake_case.
Introduced in 2.12.0.
```
snakecase "FirstName"
```
This above will produce `first_name`.
## camelcase
Convert string from snake_case to CamelCase
Introduced in 2.12.0.
```
camelcase "http_server"
```
This above will produce `HttpServer`.
## shuffle
Shuffle a string.
Introduced in 2.12.0.
```
shuffle "hello"
```
The above will randomize the letters in `hello`, perhaps producing `oelhl`.
## regexMatch
Returns true if the input string mratches the regular expression.
```
regexMatch "[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}" "test@acme.com"
```
The above produces `true`
## regexFindAll
Returns a slice of all matches of the regular expression in the input string
```
regexFindAll "[2,4,6,8]" "123456789
```
The above produces `[2 4 6 8]`
## regexFind
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`
## regexReplaceAll
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-`
## regexReplaceAllLiteral
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}-`
## regexSplit
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]`
## See Also...
The [Conversion Functions](conversion.html) contain functions for converting
strings. The [String Slice Functions](string_slice.html) contains functions
for working with an array of strings.