libpng/png2uri

#!/bin/sh
#
# png2uri version 1.0.2, July 4, 2012.
#
# NO COPYRIGHT RIGHTS ARE CLAIMED TO THIS SOFTWARE.
#
# To the extent possible under law, the author has waived all copyright and
# related or neighboring rights to this work. This work is published from
# the United States of America in 2012.
#
# This png2uri software may be used freely in any way.
#
# The source is the original work of the person named below.  No other person
# or organization has made contributions to this work.
#
# ORIGINAL AUTHORS
#     The following people have contributed to the code or comments in this
#     file.  None of the people below claim any rights with regard to the
#     contents of this file.
#
#     Glenn Randers-Pehrson <glennrp@users.sourceforge.net>
#
# png2uri is a command-line application that creates an HTML "img" tag on
# standard output containing a data URI in accordance with RFC-2397, from
# a PNG file or from a PNG datastream received from standard input.
# Other formats besides the default, PNG, are supported, via the "-f or
# --format option or, if that option was not supplied, by inspection of the
# filename extension.
#
# Usage: png2uri [-f type|--format type] [-u|--uri_only] [file]
#
#        options: -f|--format TYPE: 
#                 write "image/TYPE" instead of "image/png" in the
#                 data uri.  TYPE can be png, jpg, jpeg, bmp, or gif,
#                 or any of those in upper case.  To write any other
#                 type, include the complete MIME type as in
#                 "--format image/x-jng" or "-f audio/mpeg".
#
#                 -u|--uri_only|--url_only
#                 omit the surrounding "img" tag and only write the
#                 data URI.
#
# Requires /bin/sh and a uuencode(1) that takes the "-m" option to mean
# to encode in base64 according to RFC-3548, and a working "sed".
#
# If you prefer a web-based converter or a java application, this isn't
# it. Use your search engine and look for "png data uri" to find one.
#

uri_only="false"
format="unknown"

while true
do
case x$1 in
  x-f|x--format)
      shift
      case x$1 in
         xpng|xPNG)
           format=image/png
         ;;
         xjpeg|xJPEG|xjpg|xJPG)
           format=image/jpeg
         ;;
         xbmp|xBMP)
           format=image/bmp
         ;;
         xgif|xGIF)
           format=image/gif
         ;;
         *)
           format=$1
         ;;
      esac
      shift
      ;;
  x-u|x--ur*)
      uri_only="true"
      shift
      ;;
  x)
      # Convert standard input.
      case $format in
        unknown)
           format=image/png
           ;;
      esac
      case $uri_only in
         true)
            echo "data:$format;base64,"
            uuencode -m ==== | grep -v ====
            ;;
         false)
            echo "<img alt=\"PNG\" title=\"PNG\" src=\"data:$format;base64,"
            uuencode -m ==== | grep -v ====
            echo "\">"
            ;;
      esac
      exit
      ;;
  *)
      # Convert the named file.
      case $format in
        unknown)
           format=image/png
           extension=`echo $1 | sed "s/.*\.//"`
           case x$extension in
              xjpeg|xJPEG|xjpg|xJPG)
                format=image/jpeg
              ;;
              xbmp|xBMP)
                format=image/bmp
              ;;
              xgif|xGIF)
                format=image/gif
              ;;
            esac
         ;;
      esac
      case $uri_only in
         true)
            echo "data:$format;base64,"
            uuencode -m $1 ==== | grep -v ====
            ;;
         false)
            echo "<img alt=\"$1\" title=\"$1\" src=\"data:$format;base64,"
            uuencode -m $1 ==== | grep -v ====
            echo "\">"
            ;;
      esac
      exit
      ;;
esac
done