A Golang template engine

template: use Golang templates on the command line and hydrate them with variable values provided via YAML or JSON files.

Usage

Take a look a the _test/ directory for an example:

1. you CAN specify an input file that will contain an arbitrary JSON or YAML structure with the input variables, or alternatively pipe it in via STDIN; in the latter case if the input is in YAML format it should start with ---, if in JSON format with { or [; if the input is provided via the -i or --input argument as a file, it must be prefixed with @, otheriwse it is interpreted as an inline JSON/YAML;
2. the list of template files must be provided as multiple --template arguments pointing to their paths on disk; the first template is considered the main template (the starting point for template expansion);
3. you CAN specify the name of an output file; if left blank the application will write to STDOUT;

For example:

$> template -i=@_test/input.yaml -t=_test/outer.tpl -t=_test/inner.tpl

or

$> cat _test/input.json | template -t=_test/outer.tpl -t=_test/inner.tpl

If no output parameter is specified, template will write to STDOUT by default; thus, it can be used with pipes (|) where the STDIN is the set of input variables funnelled into template and the output goes to SDOUT and can therefore be piped into other commands.

Custom functions

template provides a set of functions to format and process data.

Besides including the whole set of functions made available by the excellent Sprig library, it provides some additional functions to enrich the template manipulation capabilities.

Function include

The include function can be used when you want to include a sub-template (or any other file) and you would like it to be padded left line by line with a fixed string. For instance this provides a way to include some file and have it automatically indented. Look at _test/outer.tpl to see how it includes a bash script prepending > to each line.

Functions from color

The following functions are made available:

• blue
• cyan
• green
• magenta
• purple
• red
• yellow
• white
• hiblue
• hicyan
• higreen
• himagenta
• hipurple
• hired
• hiyellow
• hiwhite

To use the function, do as follows in your template:

Name: {{.Name | blue}}
Surname: {{.Surname | red}}
Phone No.: {{.PhoneNo | purple }}