feat: updates, docs, license fixes, new helpers

local/bin/x-path-prepend

@@ -1,33 +1,50 @@
 #!/usr/bin/env bash
 #
-# Add a directory to the front of the PATH if it exists and is not already there
-# Usage: x-path-prepend <dir>
+# Optimized script to batch prepend directories to PATH.
+# For each given directory, it removes all duplicate occurrences from PATH
+# and then prepends it. Directories that do not exist are skipped.
+#
+# Usage: x-path-prepend <directory1> [<directory2> ...]
+#
+# Enable verbose output by setting the environment variable VERBOSE=1.
+#
+# Author: Ismo Vuorinen <https://github.com/ivuorinen> 2024
+# License: MIT
 
-# Set verbosity with VERBOSE=1
 VERBOSE="${VERBOSE:-0}"
 
-# Function to print messages if VERBOSE is enabled
-# $1 - message (string)
-msg()
-{
-  [[ "$VERBOSE" -eq 1 ]] && echo "$1"
+# Ensure that at least one argument is provided.
+[ "$#" -lt 1 ] && {
+  echo "Usage: $0 <directory> [<directory> ...]"
+  exit 1
 }
 
-if [ "$#" -ne 1 ]; then
-  echo "Usage: $0 <dir>"
-  exit 1
-fi
+# Save the arguments in an array.
+dirs=("$@")
 
-dir="$1"
+# Process the directories in reverse order so that the first argument ends up leftmost in PATH.
+for ((idx = ${#dirs[@]} - 1; idx >= 0; idx--)); do
+  dir="${dirs[idx]}"
 
-if [ ! -d "$dir" ]; then
-  msg "(?) Directory $dir does not exist"
-  exit 0
-fi
+  # Check if the specified directory exists.
+  if [ ! -d "$dir" ]; then
+    [ "$VERBOSE" -eq 1 ] && echo "(?) Directory '$dir' does not exist. Skipping."
+    continue
+  fi
 
-if echo "$PATH" | grep -qE "(^|:)$dir($|:)"; then
-  msg "(!) Directory $dir is already in PATH"
-else
+  # Remove all duplicate occurrences of the directory from PATH using built-in string operations.
+  case ":$PATH:" in
+    *":$dir:"*)
+      PATH=":${PATH}:"
+      PATH="${PATH//:$dir:/:}"
+      PATH="${PATH#:}"
+      PATH="${PATH%:}"
+      [ "$VERBOSE" -eq 1 ] && echo "Removed duplicate occurrences of '$dir' from PATH."
+      ;;
+    *) ;;
+  esac
+
+  # Prepend the directory to PATH.
   export PATH="$dir${PATH:+":$PATH"}"
-  msg "(!) Directory $dir has been added to the front of PATH"
-fi
+  [ "$VERBOSE" -eq 1 ] && echo "Prepended '$dir' to PATH."
+done