`envsubst` is not POSIX, but my preferred tool for such things: https://linux.die.net/man/1/envsubst https://linux.die.net/man/1/envsubst it's part of `gettext

`envsubst` is not POSIX, but my preferred tool for such things: https://linux.die.net/man/1/envsubst https://linux.die.net/man/1/envsubst it's part of `gettext`: https://www.gnu.org/software/gettext/manual/html_node/envsubst-Invocation.html https://www.gnu.org/software/gettext/manual/html_node/envsub...