envsubst — substitutes environment variables in shell format strings

Examples (TL;DR)

Synopsis

envsubst [OPTION] [SHELL-FORMAT]

Description

Substitutes the values of environment variables.

Operation mode

-v, --variables

output the variables occurring in SHELL-FORMAT

Informative output

-h, --help

display this help and exit

-V, --version

output version information and exit

In normal operation mode, standard input is copied to standard output, with references to environment variables of the form $VARIABLE or ${VARIABLE} being replaced with the corresponding values.  If a SHELL-FORMAT is given, only those environment variables that are referenced in SHELL-FORMAT are substituted; otherwise all environment variables references occurring in standard input are substituted.

When --variables is used, standard input is ignored, and the output consists of the environment variables that are referenced in SHELL-FORMAT, one per line.

Author

Written by Bruno Haible.

Reporting Bugs

Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>.

See Also

The full documentation for envsubst is maintained as a Texinfo manual.  If the info and envsubst programs are properly installed at your site, the command

info envsubst

should give you access to the complete manual.

Referenced By

git-sh-i18n--envsubst(1).

May 2019 GNU gettext-runtime 0.20.7-31105-dirty