Update skel, common functions.

dotfiles/commonrc.sh

@@ -0,0 +1,63 @@
+#!/bin/sh
+# shellcheck disable=SC1090
+
+# common functions for use in shell scripts
+
+find_first() {
+  while [ "$#" -gt 0 ]; do
+    if test -e "${1}" ; then
+      echo "${1}"
+      return 0
+    fi
+    shift
+  done
+  return 1
+}
+
+have_command() {
+  command -v "$1" >/dev/null 2>&1
+}
+
+# Helper function: Returns 0 if the directory is in PATH, 1 otherwise
+path_contains() {
+  case ":${PATH}:" in
+    *:"$1":*) return 0 ;;
+    *)        return 1 ;;
+  esac
+}
+
+# Prepend a directory to PATH if it's not already there
+path_prepend() {
+  if [ -d "$1" ] && ! path_contains "$1"; then
+    PATH="$1:${PATH}"
+  fi
+}
+
+# Append a directory to PATH if it's not already there
+path_append() {
+  if [ -d "$1" ] && ! path_contains "$1"; then
+    PATH="${PATH}:$1"
+  fi
+}
+
+source_first_existing() {
+  _sfe_script="$(find_first "$@")"
+  _sfe_status=$?
+
+  if [ "$_sfe_status" -eq 0 ]; then
+    . "$_sfe_script"
+    # Clean up our temporary variables before returning success
+    unset -v _sfe_script _sfe_status
+    return 0
+  fi
+
+  # Clean up our temporary variables before returning failure
+  unset -v _sfe_script _sfe_status
+  return 1
+}
+
+source_if_existing() {
+  if [ -f "$1" ]; then
+    . "$1"
+  fi
+}