envsubst - substitutes environment variables in shell format strings
envsubst [
OPTION] [
SHELL-FORMAT]
Substitutes the values of environment variables.
-
-v, --variables
- output the variables occurring in SHELL-FORMAT
-
-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.
Written by Bruno Haible.
Report bugs in the bug tracker at
<
https://savannah.gnu.org/projects/gettext> or by email to
<
[email protected]>.
Copyright © 2003-2020 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.
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.