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.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
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