Initial commit: CLI walkthrough for CHEG 667-013

Six-module walkthrough covering navigation, files, reading/searching,
processes/editors, scripting, and advanced tools (ssh, regex, tar, etc.).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

05-scripting/weather.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# weather.sh [-s STATE] [ZONE]
+
+usage() { echo "Usage: $0 [-s STATE] [ZONE]" 1>&2; exit 1; }
+
+STATE="de"
+ZONE="001"
+
+while getopts "s:" flag; do
+  case "$flag" in
+    s) STATE="$OPTARG" ;;
+    *) usage ;;
+  esac
+done
+shift $((OPTIND - 1))
+
+# Allow 0 or 1 positional arg (ZONE)
+if [ "$#" -gt 1 ]; then
+  usage
+fi
+
+if [ "$#" -eq 1 ]; then
+  if [[ ! "$1" =~ ^[0-9]{3}$ ]]; then
+    usage
+  fi
+  ZONE="$1"
+fi
+
+STATE="${STATE,,}"  # lowercase
+
+curl -s "https://tgftp.nws.noaa.gov/data/forecasts/zone/${STATE}/${STATE}z${ZONE}.txt"