You need rustc compiler and ln command, run this:
rustc -o hex2rgb hex2rgb.rs && command ln -s hex2rgb rgb2hexRun without argument to show the help screen.
rgb2hex requires you to enter three arguments, which are red, green and blue.
Unlike the hex2rgb, the rgb2hex can only produce one result at a time.
hex2rgb can accept two kind of argument value, a value with a pawn sign # or without a pawn sign.
If there is a pawn sign in the argument value, you need to quote it, or else the shell may interpret it as a comment not as a value.
hex2rgb can accept more than one argument value and produce more than one result at a time.
Check the help screen for some example.