gtkdialog gui for Puppy Linux to recursively find and combine pdf files

gjoinpdf

#! /bin/bash
# gjoinpdf: gtkdialog gui for Puppy Linux to recursively find and combine pdf files.
# Requires qpdf (or pdfunite from poppler, or gs) and basename.
# See joinpdf for command-line only version.
# Version 7 by disciple, 06/12/2022.
# http://www.murga-linux.com/puppy/viewtopic.php?p=149208#149208
# Currently has NO ERROR HANDLING for the actual join operation.
# You may experience errors if you have pdfs that are corrupted.
# The use of all those symlinks is an ugly hack from when I couldn't get gs to join files with spaces in the path otherwise :(
# Maybe we should fix it if we aren't using gs anymore!

# Set defaults
INPUTFOLDER="`pwd`"
# We don't change directory, so we only need a `pwd` for the sake of the user
OUTPUTFILE="`pwd`/combined.pdf"
VIEWPROGRAM="xdg-open"
URL_HANDLER="xdg-open"
#Could use something like this if xdg-open doesn't work everywhere
#VIEWPROGRAM="`which rox || which xdg-open || which mimeo`"
#URL_HANDLER="`which defaultbrowser || which xdg-open || which mimeo`"

# Use natsort if it is available, for better sorting
# `msort -l -w -c h` also gives good results but isn't designed for piping
if hash natsort 2>/dev/null; then
 SORT="natsort"
else
 echo "gjoinpdf: using sort"
 echo "for better results install natsort from https://github.com/jjk-jacky/natsort"
 sort -V 1>/dev/null 2>&1 <<<1
 if [ $? = "0" ]
  then 
   SORT="sort -V"
  else
   SORT="sort"
   echo "gjoinpdf: sort does not support -V"
   echo "I hope you were careful with any file numbering"
 fi
fi

# Initialise filecount
# Will need to increase this if we want to join 10000+ files!
# I have not tested to find the maximum number of files in each input directory,
# although it performed well on my system with an input directory containing 960 files.
# Note that if there are too many our pipes will break!
FILECOUNT=1000

export MAIN_DIALOG="
<window title=\"gjoinpdf - combine pdfs\" icon-name=\"gtk-file\">
 <vbox>
  <edit editable=\"false\"
        wrap-mode=\"3\"
        cursor-visible=\"false\">
   <default>
\"gjoinpdf will recursively find and join all the pdfs in a directory and any number of subdirectories in normal alphanumeric order.

Make sure you name the files and folders appropriately so they are joined in the order you want.

e.g. Pdfs in a subfolder called "A" will come after a file called "1.pdf", and before a file called "B.pdf"\"
   </default>
   <height>180</height>
  </edit>
 <frame Location of input files>
   <hbox>
    <entry accept=\"directory\"
           fs-filters-mime=\"application/pdf\"
           fs-title=\"Select folder with input files\">
     <variable>INPUTFOLDER</variable>
     <input>echo '$INPUTFOLDER'</input> 
    </entry>
    <button>
     <input file stock=\"gtk-open\"></input>
     <action type=\"fileselect\">INPUTFOLDER</action>
    </button>
   </hbox>
  </frame>
  <frame Output file>
   <hbox>
    <entry accept=\"savefilename\"
           fs-filters-mime=\"application/pdf\"
           fs-title=\"Select output file\"
           is-focus=\"true\">
     <variable>OUTPUTFILE</variable>
     <input>echo '$OUTPUTFILE'</input>
    </entry>
    <button>
     <input file stock=\"gtk-new\"></input>
     <action type=\"fileselect\">OUTPUTFILE</action>
    </button>
   </hbox>
  </frame>
  <frame View the file afterwards?>
   <hbox>
    <checkbox>
     <label>View output with</label>
     <default>true</default>
     <variable>VIEWOUTPUT</variable>
    </checkbox>
    <entry accept=\"filename\"
           fs-title=\"Select pdf viewer\">
     <variable>VIEWPROGRAM</variable>
     <input>echo '$VIEWPROGRAM'</input>
    </entry>
    <button>
     <input file stock=\"gtk-execute\"></input>
     <action type=\"fileselect\">VIEWPROGRAM</action>
    </button>
   </hbox>
  </frame>
  <hbox>
   <button use-underline=\"true\">
    <input file stock=\"gtk-ok\"></input>
    <label>_Join pdfs</label>
    <action type=\"exit\">JOIN-NOW</action>
   </button>
   <button use-underline=\"true\">
    <input file stock=\"gtk-help\"></input>
    <label>_Help</label>
    <action>launch:HELP_DIALOG</action>
   </button>
   <button cancel></button>
  </hbox>
 </vbox>
</window>
"

export HELP_DIALOG="
<window title=\"gjoinpdf - info\" icon-name=\"gtk-help\">
<vbox>  
 <edit editable=\"false\"
       wrap-mode=\"3\"
       cursor-visible=\"false\">
  <default>
\"If you run gjoinpdf from the command line with inputs, it will pop up a dialog to ask you what you want to save the combined file as, and will then join them as you would expect.

i.e. If you specify an input folder it will recursively search for all pdfs in the folder and all subfolders, and sort them in normal alphanumeric order.

If you specify more than one input (file or folder), it will keep them in the order that you specify (folders won't be sorted before files), and for each folder it will sort the pdfs found there.

If you type in an output filename you do not need to add a .pdf extension; the script will sort that out.

gjoinpdf is the gui version - a command-line only version is also provided as joinpdf.

Files are sorted most sensibly if you install natsort, otherwise coreutils \`sort -V\` is used.  If you only have busybox sort you should be careful to add leading zeros to numbered filenames, e.g. to avoid 11.pdf coming before 2.pdf.
\"
  </default>
  <height>400</height>
  <width>440</width>
 </edit>
 <hbox>
  <button use-underline=\"true\">
   <input file stock=\"gtk-dialog-info\"></input>
   <label>\"_Visit forum thread\"</label>
   <action>$URL_HANDLER http://www.murga-linux.com/puppy/viewtopic.php?p=149208#149208 >/dev/null &</action>
  </button>
  <button has_focus=\"true\" use-stock=\"true\" label=\"gtk-ok\" >
   <action>closewindow:HELP_DIALOG</action>
  </button>
 </hbox>
</vbox>
<variable>HELP_DIALOG</variable>
</window>
"

generate_output_file_dialog()
{
export OUTPUT_FILE_DIALOG="
<window title=\"gjoinpdf - combine pdfs\" icon-name=\"gtk-file\">
<vbox>
  <frame Select output file>
   <hbox>
    <entry accept=\"savefilename\"
           fs-filters-mime=\"application/pdf\"
           fs-title=\"Select output file\"
           is-focus=\"true\">
     <variable>OUTPUTFILE</variable>
     <input>echo '$OUTPUTFILE'</input>
    </entry>
    <button>
     <input file stock=\"gtk-new\"></input>
     <action type=\"fileselect\">OUTPUTFILE</action>
    </button>
   </hbox>
  </frame>
  <frame View the file afterwards?>
   <hbox>
    <checkbox>
     <label>View output with</label>
     <default>true</default>
     <variable>VIEWOUTPUT</variable>
    </checkbox>
    <entry accept=\"filename\"
           fs-title=\"Select pdf viewer\">
     <variable>VIEWPROGRAM</variable>
     <input>echo '$VIEWPROGRAM'</input>
    </entry>
    <button>
     <input file stock=\"gtk-execute\"></input>
     <action type=\"fileselect\">VIEWPROGRAM</action>
    </button>
   </hbox>
  </frame>
 <hbox>
  <button use-underline=\"true\">
   <input file stock=\"gtk-ok\"></input>
   <label>_Join pdfs</label>
   <action type=\"exit\">_JOIN-NOW</action>
  </button>
  <button cancel></button>
 </hbox>
</vbox>
</window>
"
}

export ERROR_DIALOG="
<window title=\"gjoinpdf - error\" icon-name=\"gtk-dialog-error\">
<vbox>
 <text>
  <label>ERROR: no pdf files were found.</label>
 </text>
 <button ok></button>
</vbox>
</window>
"

export ERROR_DIALOG_EXISTS="
<window title=\"gjoinpdf - file exists\" icon-name=\"gtk-dialog-error\">
<vbox>
 <text>
  <label>ERROR: the specified output file already exists; choose another one.</label>
 </text>
 <button ok></button>
</vbox>
</window>
"

export ERROR_DIALOG_PATH="
<window title=\"gjoinpdf - save error\" icon-name=\"gtk-dialog-error\">
<vbox>
 <text>
  <label>ERROR: the specified output file is in a location which is read-only or does not exist; choose another one.</label>
 </text>
 <button ok></button>
</vbox>
</window>
"

showoutputfiledialog()
{
 generate_output_file_dialog
 OUTPUTFILEGUI="`gtkdialog --program=OUTPUT_FILE_DIALOG`"
 OUTPUTFILE="`echo "$OUTPUTFILEGUI" | grep OUTPUTFILE | cut -f 2 -d '"' | sed 's/\"//g' `"
 if [ "`echo "$OUTPUTFILEGUI" | grep EXIT | cut -f 2 -d '\"' | sed 's/\"//g'`" != "JOIN-NOW" ]; then
  # if we don't clean up the temporary directory here we need to use return rather than exit
  # it is simpler to duplicate the cleanup code here than to use check the return value everywhere this function is called
  rm -rf "$TEMPFOLDER"
  exit 0
 fi
 VIEWOUTPUT="`echo "$OUTPUTFILEGUI" | grep VIEWOUTPUT | cut -f 2 -d '"' | sed 's/\"//g' `"
 VIEWPROGRAM="`echo "$OUTPUTFILEGUI" | grep VIEWPROGRAM | cut -f 2 -d '"' | sed 's/\"//g' `"
}

joinfiles()
{
 # if the file already exists don't try to overwrite it
 if [ -a "$OUTPUTFILE" ]; then
  gtkdialog --program=ERROR_DIALOG_EXISTS >/dev/null
  showoutputfiledialog
  joinfiles

 # Join files together if the output file is somewhere writable
 elif [ -w "`dirname "$OUTPUTFILE"`" ]; then
  # pdfunite is MUCH faster than gs and less error prone
  # qpdf is MUCH faster than pdfunite; let's hope it is also reliable
  if hash qpdf 2>/dev/null; then
   qpdf --empty --pages "$TEMPFOLDER"/* -- "$OUTPUTFILE" && echo "created: $OUTPUTFILE"
  else
   echo "gjoinpdf: qpdf is not available; combining files with pdfunite"
   echo "this is significantly slower"
   if hash pdfunite 2>/dev/null; then
    pdfunite "$TEMPFOLDER"/* "$OUTPUTFILE" && echo "created: $OUTPUTFILE"
   else
    echo "gjoinpdf: pdfunite is not available; combining files with gs"
    echo "this is significantly slower and more error prone"
    gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile="$OUTPUTFILE" "$TEMPFOLDER"/* && echo "created: $OUTPUTFILE"
   fi
  fi
  # View or postprocess output file
  if [[ "$VIEWOUTPUT" = "true" && "$VIEWPROGRAM" != "" ]]; then
   $VIEWPROGRAM "$OUTPUTFILE" &
  fi

 else
  gtkdialog --program=ERROR_DIALOG_PATH >/dev/null
  showoutputfiledialog
  joinfiles
 fi
}

# Show full gui if run without input arguments.
# can also do this test in one step, but it isn't really as clear:
#if [ -sd "$@" != "0" ]; then
test -sd "$@" 2>/dev/null
if [ "$?" = "0" ]; then
 MAINGUI="`gtkdialog --program MAIN_DIALOG`"
 if [ "`echo "$MAINGUI" | grep EXIT | cut -f 2 -d '\"' | sed 's/\"//g'`" != "JOIN-NOW" ]; then
  exit 0
 fi
 INPUTFOLDER="`echo "$MAINGUI" | grep INPUTFOLDER | cut -f 2 -d '"' | sed 's/\"//g' `"
 OUTPUTFILE="`echo "$MAINGUI" | grep OUTPUTFILE | cut -f 2 -d '"' | sed 's/\"//g' `"
 VIEWOUTPUT="`echo "$MAINGUI" | grep VIEWOUTPUT | cut -f 2 -d '"' | sed 's/\"//g' `"
 VIEWPROGRAM="`echo "$MAINGUI" | grep VIEWPROGRAM | cut -f 2 -d '"' | sed 's/\"//g' `"

 # Create temporary directory
 TEMPFOLDER="`mktemp -dt joinpdf-XXX`"

 # Find all files!
 #see comment further down re mime types vs file extensions
 # find -L "$INPUTFOLDER" -type f -name '*.pdf' | $SORT >> $TEMPFOLDER/files.txt
 find -L "$INPUTFOLDER" -type f -exec realpath {} + | $SORT>> "$TEMPFOLDER"/files0.txt

 # Note this doesn't work:
 # I read somewheree that each -exec is a test, but they don't seem to be tests, as this will grep the realpath of everything, 
 # as well as the mime-types.  So our list will include anything named *application/pdf
 #find "$INPUTFOLDER" -type f -exec realpath {} + \
 #                            -exec file -F $'\t' --mime-type {} + \
 #                            |grep 'application/pdf$' | cut -f 1 >> "$TEMPFOLDER"/files.txt

# Show reduced gui if run with input arguments.
else
 # Get output filename
 showoutputfiledialog
 
 # Create temporary directory
 TEMPFOLDER="`mktemp -dt joinpdf-XXX`"
 
 # Find all files!
 #see comment below re mime types vs file extensions
 for i in "$@"
  do
   #find -L "$i" -type f -name '*.pdf' | $SORT >> "$TEMPFOLDER"/files.txt
   find -L "$i" -type f -exec realpath {} + | $SORT >> "$TEMPFOLDER"/files0.txt                  
  done
fi

# get input files; detect pdfs by mime-type now
# this is more 'nixy and will pick up pdfs without a file extension, and not files with a .pdf extension that aren't actually pdfs
# need to use realpath above to pick up symlinks to pdfs (readlink would be a more portable alternative - would it be slower?)
# unfortunately (in terms of performance) we can't use the file command via find -exec because it doesn't get passed the realpath
# see https://unix.stackexchange.com/questions/79222/how-can-i-efficiently-dereference-all-symlinks-in-find-output-filenames

while IFS='' read -r line
do
 file -F $'\t' --mime-type "$line" | grep 'application/pdf$' | cut -f 1 >> "$TEMPFOLDER"/files.txt
done < "$TEMPFOLDER"/files0.txt

# Make sure output file has an extension
OUTPUTFILE="`echo $OUTPUTFILE | gawk '{gsub (/\.pdf$|\.PDF$/,"",$0); print $0'}`"
OUTPUTFILE="$OUTPUTFILE.pdf"

# Symlink files for us to join
while read line
do FILECOUNT=$(($FILECOUNT+1))
 # Used to use this, but I don't think realpath is needed
 # ln -s "`realpath "$line"`" "$TEMPFOLDER"/$FILECOUNT
 ln -s "$line" "$TEMPFOLDER"/$FILECOUNT
done < "$TEMPFOLDER"/files.txt

# Remove lists
rm -f "$TEMPFOLDER"/files0.txt
rm -f "$TEMPFOLDER"/files.txt

if [ -z "`ls -A "$TEMPFOLDER"`" ]; then
 gtkdialog --program=ERROR_DIALOG >/dev/null
else
 joinfiles
fi

#remove temporary directory
rm -rf "$TEMPFOLDER"