#!/bin/bash
#
# Syntax:  pdl [-h]
#
# Purpose: Shows the most recently changed .pdf file in the current directory
#          using acroreader, okular, xpdf, epdfview, gv, ghostview, or evince
#          (where the first command of this list that can be found is used).
#          The -h flag shows the help info for this command.

# Created: Feb  9, 2005       by Bart De Schutter
# Last revised: Jul 20, 2015  by Bart De Schutter
#
# See http://www.deschutter.info/util/scripts.html for the latest version of
# this script.

# Status: public
# Category: pdf, latex

if [  $# -ge 1   -a   "$1" = "-h"  ];
then
   sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
   exit 1
fi

if [ $# -ne 0 ];
then 
   echo >&2
   echo >&2 "ERROR: ${0##*/} requires no input arguments."
   echo >&2
   sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
   exit 1
fi

pdffile=$( (ls -t *.pdf | head -n 1) 2>/dev/null)
if [ -n "$pdffile" ];
then
   pdf_viewer=$(type -p acroread)
   options=""
   if [ -z "$pdf_viewer" ]
   then
      pdf_viewer=$(type -p okular)
      options=""
      if [ -z "$pdf_viewer" ]
      then
         pdf_viewer=$(type -p xpdf)
         options="-z page"
         if [ -z "$pdf_viewer" ]
         then
            pdf_viewer=$(type -p epdfview)
            options=""
            if [ -z "$pdf_viewer" ]
            then
               pdf_viewer=$(type -p gv)
               options=""
               if [ -z "$pdf_viewer" ]
               then
                  pdf_viewer=$(type -p ghostview)
                  options=""
                  if [ -z "$pdf_viewer" ]
                  then
                     pdf_viewer=$(type -p evince)
                     options=""
                     if [ -z "$pdf_viewer" ]
                     then
                        echo >&2
                        echo >&2 "ERROR: No pdf viewer found on this system."
                        echo >&2
                        exit 1
                     fi
                  fi
               fi
            fi
         fi
      fi
   fi
   $pdf_viewer $options "$pdffile" &
else
   echo "No .pdf files found in the current directory."
fi