Shell script that will resizes one or more images to a fixed width using the DocumentAlchemy API

resize-image.sh

#!/bin/bash
# Resizes one or more images to a fixed width using the DocumentAlchemy API

# USAGE: resize.sh <NEW-WIDTH> <FILES>
#
# EXAMPLE: resize.sh 180 images/*.png

# The generated files will have the same name (and location) as their source
# image, but with '-resized' inserted between the filename and the extension.

# This is your DocumentAlchemy API key.  It may be set via the
# environment variable named `DA_API_KEY`.
# (See <https://documentalchemy.com/> to get one of your own.)
API_KEY=${DA_API_KEY:-"403l1zh3dkbakyb9"}

# This is a flag that can prevent this script from `echo`ing
# unnecessary information.  It can be set via the environment
# variable `QUIET`. A clever person could make this into a
# command line parameter like `-q`.
QUIET=${QUIET:-FALSE}

# Note that you can set environment variables on a per-invocation
# basis by prefixing NAME=VALUE before the command.  For example:
#   API_KEY=my-key QUIET=true doc2docx *.doc

# utility function to show simple help
function usage {
  echo "USE: $0 <SIZE> <IMAGES>";
}

# EXIT_CODE tracks the number of IMAGES we couldn't resize.
EXIT_CODE=0

# The first argument contains the desired size:
NEW_WIDTH=$1

# The rest will be filenames, so "shift" the first argument away and prcess the rest.
shift;

# Loop over the command line parameters....
for img in "$@"; do
  # ...testing that is is an accessible file...
  if ! [ -s "$img" ]; then
    $QUIET || echo "WARNING: File '$img' was not found and will be ignored."
    EXIT_CODE=$((EXIT_CODE+1))
  else
    # ...if so, POST to DocumentAlchemy to resize the image...
    outfile="`echo "${img}" | sed -E 's/\.[a-z]+$/-resized.png/'`";
    $QUIET || echo "Resizing '$img' into '`basename "$outfile"`'...";
    response=$(curl --silent \
                    --write-out %{http_code} -H "Authorization: da.key=$API_KEY" \
                    -X POST --form "document=@$img" \
                    https://documentalchemy.com/api/v1/document/-/rendition/png/transform/S$NEW_WIDTH,0 \
                    -o "$outfile")
    # ...and report success or failure.
    if ! [ "$response" -eq "200" ]; then
      $QUIET || echo "WARNING: Expected a 200 response for file '$img', found $response instead.";
      EXIT_CODE=$((EXIT_CODE+1))
    else
      $QUIET || echo "...OK. File '$outfile' created."
    fi
  fi
done

# Exit with the number of documents that could not be converted.
exit $EXIT_CODE