ContainedBlargh / sub

Substitute text and colors.

Sub

Substitutes strings

Ever thought that sed and awk were sedulously awkward to use? Ever wondered how ASCII art might look if we could give it some color?

Well, wonder no more!

sub is written in Rust and uses the colored, argparse, hex and regex libraries to let you replace and color characters directly from stdin.

Usage

Usage:
  sub [OPTIONS] REPLACEMENT STRING SUBSTITUTION STRING

Replace characters, regular expressions or colors read from stdin.

Positional arguments:
  replacement string    The string to use for replacing.
  substitution string   The string to substitute with.

Optional arguments:
  -h,--help             Show this help message and exit
  -r,--regex            Interpret argument as regular expression.
  -c,--capture          Inject captured strings into substitute using &n where
                        n is a group number.
  -f,--fg FG            Set a new foreground color.
  -b,--bg BG            Set a new background color.

Example - Merry Christmas

Ah, just in time for Christmas, I've found a christmas tree online.

         v
        >X<
         A
        d$b
      .d\$$b.
    .d$i$$\$$b.
       d$$@b
      d\$$$ib
    .d$$$\$$$b
  .d$$@$$$$\$$ib.
      d$$i$$b
     d\$$$$@$b
  .d$@i$\$$i$$@b.
.d$i$$$$$$\$$$$$$b.
        ###
        ###
        ###

But, it looks rather dull, does it not?

Well, with a little help from sub, we can give it some colors!

cat .\xmas_tree.txt | sub -f '#F4F556' i i | sub -f "#009302" -rc '([\.bd$])' '&1' | sub -f '#FFC300' -rc '([v<>XA])' '&1' | sub -f "#733719" '#' '#' | sub -f "FF5533" '@' '@' | sub -f "#0F73D9" '\' '\'

Let's break it down a bit:

• cat outputs our tree to stdout.
• Each call to sub reads every line from stdin and writes the modified lines to stdout.
• sub -f '#F4F556' i i sets a foreground color to each of the i-characters (the candles) in our tree. It replaces each i with another i, but applies the foreground color too.
• sub -f "#009302" -rc '([\.bd$])' '&1' matches all the characters in the pattern [\.bd$], determined by the -r flag. It also captures all the characters in the pattern, determined by the -c flag and the parentheses outside the pattern. Then, it replaces the matched characters with ... themselves, since '&1' refers to the first group captured.

The rest of the calls use the same flags with different characters and colors.

Requirements

A true-color terminal. Microsoft added the Windows Terminal, which you can get on the Windows store. If you are running Linux, most terminals should support true-color.

Installation

You can download a build for Windows or Linux from the releases page.