Record a window excluding title bar of a macOS application

record-window

#!/bin/bash
# record-window

function usage() {
   echo "usage: record-window [-hf] [-n window-number] <application> <capture.mov>" >&2;
   echo "       -h help; show usage (this)" >&2;
   echo "       -f force recording (remove previous output file if present)" >&2;
   echo "Record a window excluding title bar of an application (case-sensitive)" >&2;
}

window_number="1";
force=0;
while getopts n:hf opt; do
    case $opt in
      h) usage; exit 1;;
      f) force=1;;
      n) window_number="$OPTARG";;
      *) echo "error: invalid option given." >&2; usage; exit 2;
    esac
done
shift $[ OPTIND - 1 ]

if [ $# -ne 2 ]; then
   usage;
   exit 3;
fi

app="$1";
capture="$2";
window_header="28";

rect=$(osascript <<EOF 2>&1 | tr -d ' '
set windowHeader to $window_header
tell application "System Events"
    tell process "$app"
        activate
        tell window $window_number
            set thePosition to position
            set theSize to size
            log ((item 1 of thePosition)&((item 2 of thePosition) + windowHeader) & (item 1 of theSize) & ((item 2 of theSize) - windowHeader))
        end tell
    end tell
end tell
EOF);

if [ $force -eq 1 ] && [ -f "$capture" ]; then
   rm "$capture";
fi
screencapture -v -R$rect "$capture";