tmpl

Command tmpl renders a template with the current env vars as input.

$ tmpl -h
Usage of tmpl:
  -f string
         	Input source (default "-")

It includes all of the template helpers from sprig.

It effectively exposes Go's text/template for use in shells.

Reference text/template documentation for template language specification.

Example 1

Given a file 'a' with contents:

{{ range $key, $value := . }}
  KEY:{{ $key }} VALUE:{{ $value }}
{{ end }}

Invoking

$ cat a | env -i ANSWER=42 ITEM=Towel `which tmpl`

Produces

KEY:ANSWER VALUE:42

KEY:ITEM VALUE:Towel

Example 2

Given a file 'b' with contents:

VERSION={{.HEAD}}

Invoking

$ cat b | HEAD="$(git rev-parse HEAD)" tmpl

Produces

VERSION=4dce1b0a03b59b5d63c876143e9a9a0605855748