envsubst - substitutes environment variables in shell format strings
envsubst [OPTION] [SHELL-FORMAT]
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.
Written by Bruno Haible.
Report bugs in the bug tracker at <https://savannah.gnu.org/projects/gettext> or by email to <bug-gettext@gnu.org>.
Copyright
© 2003-2023 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.