GNU gettext utilities: sh-format
From Get docs
Gettext/docs/latest/sh 002dformat
Next: awk-format, Previous: ruby-format, Up: Translators for other Languages [Contents][Index]
15.3.12 Shell Format Strings
Shell format strings, as supported by GNU gettext and the ‘envsubst
’ program, are strings with references to shell variables in the form $variable
or ${variable}
. References of the form ${variable-default}
, ${variable:-default}
, ${variable=default}
, ${variable:=default}
, ${variable+replacement}
, ${variable:+replacement}
, ${variable?ignored}
, ${variable:?ignored}
, that would be valid inside shell scripts, are not supported. The variable
names must consist solely of alphanumeric or underscore ASCII characters, not start with a digit and be nonempty; otherwise such a variable reference is ignored.