From 8c218457e8ccc55175934a3bfabb364fae319884 Mon Sep 17 00:00:00 2001
From: Connor Olding <cloningdonor@gmail.com>
Date: Mon, 29 Aug 2022 22:06:15 -0700
Subject: [PATCH] add an esoteric function to rotate PATHs

---
 home/shrc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/home/shrc b/home/shrc
index 1a5d6ee..adafcd2 100644
--- a/home/shrc
+++ b/home/shrc
@@ -36,6 +36,19 @@ ADDPATH() { ### @- append a directory to `$PATH` if it isn't already present.
     esac
 }
 
+ROPATH() {
+    [ $# -eq 0 ] || { printf '%s: expected exactly %s arguments, got %s\n' ROPATH 0 $# >&2; return 2; }
+    local segment= previous= newpath= oldpath="$PATH:"
+    while segment="${oldpath%%:*}"; [ "$segment" != "$oldpath" ]; do
+        [ -z "$segment" ] || [ -z "$previous" ] || newpath="$newpath$previous:"
+        [ -z "$segment" ] || previous="$segment"
+        oldpath="${oldpath#*:}"
+    done
+    [ -z "$previous" ] || printf 'rotated %s\n' "$previous" >&2
+    [ -z "$previous" ] || newpath="$previous:$newpath"
+    export PATH="${newpath%:}"
+}
+
 # {{{1 configurations
 
 umask 022 # umask should be reset else pip might make faulty installations.