Add zsh/lolcat.zsh rainbow helpers + document in README

zsh/lolcat.zsh

@@ -0,0 +1,31 @@
+# zsh/lolcat.zsh (drunkendotfiles) — auto-sourced via ~/.zshrc: for f in ~/.yadr/zsh/*.zsh
+# Rainbow-output helpers built on lolcat (jaseg's C build at /usr/games/lolcat).
+# This lolcat is truecolor and auto-detects a tty: it colorizes when writing
+# straight to the terminal, but passes text through UNcolored when piped onward,
+# so use -f/--force to colorize in the middle of a pipeline.
+
+# Debian ships lolcat in /usr/games; make sure it's reachable in any shell.
+[[ ":$PATH:" == *":/usr/games:"* ]] || export PATH="$PATH:/usr/games"
+
+# --- opt-in: prefix ANY command to rainbow its output on the terminal --------
+#   lol ls -C        lol fastfetch        lol git log --oneline
+# (The wrapped command sees a pipe, not a tty, so some tools drop their own
+#  colors/columns -- e.g. use `lol ls -C` to keep ls in columns.)
+lol()  { "$@" | lolcat; }
+
+# Same, but force color so it survives further down a pipeline:
+#   lolf git diff | less -R
+lolf() { "$@" | lolcat -f; }
+
+# --- handy rainbow shortcuts for plain-text output ---------------------------
+rcat()  { lolcat "$@"; }              # rcat file.txt   (or:  some-cmd | rcat)
+rls()   { ls -C "$@" | lolcat; }      # rainbow ls, columns preserved
+rless() { lolcat -f | less -R; }      # pipe into me:   some-cmd | rless
+
+# --- whole-session "rainbow everything" toggle (NOVELTY) ---------------------
+# Pipes the shell's stdout through lolcat until turned off. It WILL garble
+# full-screen/interactive programs (vim, less, htop, fzf, ssh) and your prompt,
+# and buffers streaming output. Use it for a burst of plain command output,
+# then rainbow_off. Does not affect stderr.
+rainbow_on()  { [[ -n $RAINBOW_PIPE ]] && return; exec 3>&1; exec > >(lolcat -f); export RAINBOW_PIPE=1; }
+rainbow_off() { [[ -z $RAINBOW_PIPE ]] && return; exec 1>&3 3>&-; unset RAINBOW_PIPE; }