giphy-grab

#!/usr/bin/env bash
set -e

usage() {
  echo "giphy-grab [-f|--force] [-s|--skip-title] [-o|--output] <url>"
  echo "            --force: overwrite output file if it exists"
  echo "            --skip-title: don't fetch GIF name from GIPHY"
  echo "            --output: filename or destination folder for GIF"
  exit 1
}

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"
case $key in
    -h|--help)
    usage
    shift
    shift
    ;;
    -f|--force)
    OVERWRITE="true"
    shift
    ;;
    -s|--skip-title)
    SKIP_TITLE="true"
    shift
    ;;
    -o|--output)
    OUTPUT="$2"
    shift
    shift
    ;;
    *) # unknown, save for later unpacking
    POSITIONAL+=("$1")
    shift
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore unflagged params

if (( ${#POSITIONAL[@]} < 1 )); then
  usage
fi

extract_id() {
  echo "$1" | grep -E -o "\b[a-zA-Z0-9]{10,20}\b"
}

fetch_title() {
  curl -L -s "https://giphy.com/gifs/$1" \
    | grep -E -o "<title>.+</title>" \
    | sed -E 's/\<[^>]+\>//g' \
    | sed -E 's/ GIF.* - Find &amp; Share on GIPHY//'
}

URL="$1"
ID=$(extract_id "$URL")
GIF_URL="http://i.giphy.com/media/${ID}/giphy.gif"

if [[ "$SKIP_TITLE" ]] && [[ -z "$OUTPUT" ]]; then
  echo "-o|--output must be used when -s|--skip-title flag is set" >&2
  exit 1
fi

if [[ -z "$SKIP_TITLE" ]]; then
  COMPUTED_NAME=$(fetch_title "$ID")
  COMPUTED_NAME="${COMPUTED_NAME}.gif"
fi


if [[ "$OUTPUT" ]]; then
  # must be passed as last argument
  if [[ -d "$OUTPUT" ]] && [[ "$COMPUTED_NAME" ]]; then
    OUTPUT="${OUTPUT}/${COMPUTED_NAME}"
  fi
else
  OUTPUT="$COMPUTED_NAME"
fi
cmd=(curl -L --output "$OUTPUT" "$GIF_URL")

if [[ -e "$OUTPUT" ]] && [[ -z "$OVERWRITE" ]]; then
  echo "$OUTPUT exists and -f|--force not set. Exiting"
  exit 1
fi

echo "Destination URL: $URL | Output: ${OUTPUT}"
#echo "${cmd[@]}"

"${cmd[@]}"