ENVSUBST(1) User Commands ENVSUBST(1)

# [NAME](#NAME)

envsubst - substitutes environment variables in shell format strings

# [SYNOPSIS](#SYNOPSIS)

**envsubst** \[*OPTION*] \[*SHELL-FORMAT*]

# [DESCRIPTION](#DESCRIPTION)

Substitutes the values of environment variables.

## [Operation mode:](#Operation_mode:)

[**-v**, **--variables**](#v)

output the variables occurring in SHELL-FORMAT

## [Informative output:](#Informative_output:)

[**-h**, **--help**](#h)

display this help and exit

[**-V**, **--version**](#V)

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](#AUTHOR)

Written by Bruno Haible.

# [REPORTING BUGS](#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)

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](#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.

October 2026 GNU gettext-runtime 1.0

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Document: envsubst(1) from gettext 1.0-r8 (Chainguard OS)
Source: https://git.savannah.gnu.org/git/gettext.git