util-xlab

A small set of utility programs for OSv: List:

• cd.so

template

Main purpose of this program is to ease runtime customization of application configuration through environment variables.

template program takes two paths as arguments. First path should point to the file that will serve as a template that gets expanded using environment variables similar to how bash expands variables in strings. Second path should point to the destination file. For example:

$ cat a.txt
Name of master is ${MASTER_NAME} and worker is ${WORKER_NAME}.
$ MASTER_NAME=abc WORKER_NAME=123 ./template a.txt b.txt
$ cat b.txt
Name of master is abc and worker is 123.

Template variables that are not found in environment are replaced by empty string.

Variables that should be expanded are marked with ${VAR} construct. Note that $VAR will not be expanded and will be copied to the output file verbatim.