articles/cmd/mov2gif: add

#168

articles/cmd/adblock.md

@@ -1,8 +1,7 @@
 # cmd / adblock
 
 To improve speed, privacy, and safety on my laptop,
-[the `adblock` script](https://github.com/croaky/laptop/blob/main/bin/adblock)
-blocks ads, trackers, and malicious websites at the DNS host level:
+I block ads, trackers, and malicious websites at the DNS host level:
 
 ```bash
 adblock
@@ -12,7 +11,7 @@ Unlike browser extension ad blockers,
 it works on all apps on my device (not only web browsers).
 
 Unlike DNS sinkholes,
-it only works on my laptop (not phones, tablets on the network)
+it only works on my laptop (not phones or tablets on the network)
 but it does not require an additional always-on device such as a Raspberry Pi
 and it works reliably when using the laptop away from home.
 
@@ -22,3 +21,32 @@ To disable and re-enable it:
 adblock undo
 adblock
 ```
+
+Script:
+
+```bash
+#!/bin/bash
+#
+# https://github.com/croaky/laptop/blob/main/bin/adblock
+
+set -euo pipefail
+
+if [[ "$1" == "undo" ]]; then
+  echo -e '127.0.0.1\tlocalhost\n# MacOS default\n255.255.255.255\tbroadcasthost' | sudo tee /etc/hosts > /dev/null
+else
+  # Creative Commons Attribution-NonCommercial-ShareAlike
+  curl -s https://winhelp2002.mvps.org/hosts.txt > /tmp/adblock
+
+  # Re-write Windows to Unix line endings
+  tr -d '\r' < /tmp/adblock > /tmp/etchosts
+
+  # Restore macOS system defaults
+  echo -e '# MacOS default\n255.255.255.255\tbroadcasthost' >> /tmp/etchosts
+
+  # Apply to /etc/hosts
+  sudo mv /tmp/etchosts /etc/hosts
+fi
+
+# Flush DNS cache
+sudo killall -HUP mDNSResponder
+```

articles/cmd/kill-pid-on-port.md

@@ -13,5 +13,7 @@ Script:
 #
 # https://github.com/croaky/laptop/blob/main/bin/kill-pid-on-port
 
+set -euo pipefail
+
 lsof -n -i :"$1" | grep LISTEN | awk '{ print $2 }' | xargs kill
 ```

articles/cmd/mov2gif.md

@@ -0,0 +1,98 @@
+# mov2gif
+
+I record screencasts with QuickTime.app, which produces a `.mov` file.
+When I want a smaller file to share in product documentation or this blog:
+
+```bash
+mov2gif input.mov
+```
+
+`mov2gif` takes a `.mov` file as input and outputs a `.output.gif`.
+
+Script:
+
+```bash
+#!/bin/bash
+#
+# Convert a .mov file to a .gif file
+#
+# Usage: mov2gif [-f fps] [-s scale] input.mov
+#
+# Options:
+#   -f fps     Frames per second (default: 15)
+#   -s scale   Scale width in pixels (default: 1400)
+
+set -euo pipefail
+
+# Default parameters
+fps=15     # Frames per second
+scale=1400 # Scale width in pixels
+
+# Function to display usage information
+usage() {
+  echo "Usage: $0 [-f fps] [-s scale] input.mov"
+  echo "  -f fps     Frames per second (default: 15)"
+  echo "  -s scale   Scale width in pixels (default: 1400)"
+  exit 1
+}
+
+# Parse options
+while getopts ":f:s:" opt; do
+  case $opt in
+  f)
+    fps="$OPTARG"
+    ;;
+  s)
+    scale="$OPTARG"
+    ;;
+  \?)
+    echo "Invalid option: -$OPTARG" >&2
+    usage
+    ;;
+  :)
+    echo "Option -$OPTARG requires an argument." >&2
+    usage
+    ;;
+  esac
+done
+
+# Shift parsed options away
+shift $((OPTIND - 1))
+
+# Check for input file
+if [ $# -ne 1 ]; then
+  echo "Error: Missing input file."
+  usage
+fi
+
+input_file="$1"
+
+# Verify input file extension
+if [[ "${input_file##*.}" != "mov" ]]; then
+  echo "Error: Input file must have a .mov extension."
+  exit 1
+fi
+
+# Check if input file exists
+if [ ! -f "$input_file" ]; then
+  echo "Error: File '$input_file' not found."
+  exit 1
+fi
+
+# Check and install ffmpeg if not present
+if ! command -v ffmpeg &>/dev/null; then
+  echo "ffmpeg not found. Installing via Homebrew..."
+  brew install ffmpeg
+fi
+
+# Generate a palette for better colors in the GIF
+echo "Regenerating palette..."
+rm palette.png
+ffmpeg -y -i "$input_file" -vf "fps=${fps},scale=${scale}:-1:force_original_aspect_ratio=decrease,palettegen" -frames:v 1 palette.png
+
+# Create the final GIF using the palette
+echo "Creating GIF..."
+ffmpeg -i "$input_file" -i palette.png -filter_complex "fps=${fps},scale=${scale}:-1:force_original_aspect_ratio=decrease[x];[x][1:v]paletteuse=dither=none" output.gif
+
+echo "GIF created: output.gif"
+```

theme/index.html

@@ -200,6 +200,9 @@ <h3>cmd/</h3>
           <li>
             <a href="/cmd/mdembed">mdembed</a>
           </li>
+          <li>
+            <a href="/cmd/mov2gif">mov2gif</a>
+          </li>
           <li>
             <a href="/cmd/replace">replace</a>
           </li>