# ENVSUBST

NAME
SYNOPSIS
DESCRIPTION
AUTHOR
REPORTING BUGS
COPYRIGHT
SEE ALSO

## NAME

envsubst - substitutes environment variables in shell format strings

## 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>.

## COPYRIGHT

Copyright © 2003-2026 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

## 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.