envsubst

envsubst is a Go package for expanding variables in a string using ${var} syntax. Includes support for bash string replacement functions.

Documentation

Documentation can be found on GoDoc.

Supported Functions

• ${var^}
• ${var^^}
• ${var,}
• ${var,,}
• ${var:position}
• ${var:position:length}
• ${var#substring}
• ${var##substring}
• ${var%substring}
• ${var%%substring}
• ${var/substring/replacement}
• ${var//substring/replacement}
• ${var/#substring/replacement}
• ${var/%substring/replacement}
• ${#var}
• ${var=default}
• ${var:=default}
• ${var:-default}

Unsupported Functions

• ${var-default}
• ${var+default}
• ${var:?default}
• ${var:+default}