add text on 1st page of a pdf file

Question

I'm trying to add a text comment (not a note) to a pdf file. I create a date.ps file which contains the text comment:

%! 
/Arial findfont 
30 scalefont 
setfont 
newpath 
10 720 moveto 
(PAID on 5.1.2013) show 
showpage

and I launch the shell command with $i=name of the pdf file to tag:

gs \
    -q \
    -dNOPAUSE \
    -dSAFER \
    -dBATCH \
    -sOutputFile="$RFP/$DOMAINE/$NEWNAME" \
    -sDEVICE=pdfwrite \
    -sPAPERSIZE=a4 \
    date.ps \
    $i

This works, but it creates a new 1st page - empty - with just the text "PAID on 5.1.2013" alone.

I do not find the trick to overlay the text on the 1st page of the original pdf.

Answer 1

You can do this directly to the PDF using the free cpdf command line tools:

For example,

cpdf \
    -add-text "PAID on 5.1.2013" \
    -topleft 100 \
    -font "Helvetica" \
    -font-size 30 \
    in.pdf \
    -o out.pdf

Answer 2

Since cpdf has a strange license for commercial use, I tried to find an alternative. Here is one (you need to install enscript, ps2pdf and (pdftk or qpdf)). The idea is just to use enscript to create a .ps from a text, then you convert this .ps into a .pdf using ps2pdf, and then you stack it on top of the original pdf with pdftk or qpdf...).

pdtfk version:

echo "I will be stamped on top of the page" | \
    enscript -B -f Courier-Bold16 -o- | \
    ps2pdf - | \
    pdftk input.pdf stamp - output output.pdf

qpdf version:

If you want the text to repeat on all pages:

tmpfile=$(mktemp) && echo "I will be stamped on top of the page" | \
    enscript -B -f Courier-Bold16 -o- | \
    ps2pdf - "$tmpfile" && qpdf input.pdf --overlay "$tmpfile" --repeat=1-z -- output.pdf

if you just want to put it on the first page:

tmpfile=$(mktemp) && echo "I will be stamped on top of the page" | \
    enscript -B -f Courier-Bold16 -o- | \
    ps2pdf - "$tmpfile" && qpdf input.pdf --overlay "$tmpfile" -- output.pdf

See the enscript documentation for more options on how to format the text.

NB: mktemp is just used to create a temporary file to provide a one-liner solution, since qpdf does not accept input from stdin. Remove the tmpfile with rm "$tmpfile" after the command is done.

Answer 3

Because your PostScript executed a showpage it ejects the first page after marking it, so the remaining content is therefore on the 2nd and subsequent pages. If you don;t execute showpage then the marks you make will be on the first page, and the first PDF page will be drawn 'on top' of it.

More complex code can use BeginPage and EndPage to draw over and under the page contents, and to do so on specified pages, among other things.

[added later]

Try this:

%!
<< 
/EndPage 
{
  0 eq
  {
    0 eq
    {
      /Arialabold findfont 22 scalefont setfont newpath 250 820 moveto 1 0 0 setrgbcolor (PAYE PAR CCP LE $DATEPMT) show
    } if
    true
  }
  {
    pop false
  } ifelse
} >> setpagedevice

Works for me.

Answer 4

PDFtk Ghostscript and cPDF are not "Free for commercial usage".

Where as qPDF is FOSS and can do the task using a helper script, as it currently has no inbuilt editing ability.

Here is a Windows Command script for above where command was

Watermark "PAID on 5.1.2013" qpdf-manual.pdf

Watermark.cmd (proof of concept for you to edit as desired)

@echo off &rem cls & Title qPDF Watermark/Overlay with solid text
REM For PDF/A-1 & compatability with older PDFs, this file is intentionally solid color only
Rem Answer to https://stackoverflow.com/questions/18769314/add-text-on-1st-page-of-a-pdf-file
::ÿþ
Rem Variables For Letter use "Page=612 792" for A4 use "Page=594 842"
REM 1 = full color For RGB blue say "Color=0 0 1 rg" For cmyk black change to say "Color=0 0 0 1 k"
set "Page=612 792"
set "Color=1 0 0 rg"
set "Indent=72"
set "Elevation=710"
set "Font=Helvetica"
set "emSize=30"
set "Range=1"

if "%~1"=="" echo Usage "%0" "Quoted Text" "filename.pdf" &pause & exit /b
if /i "%~x2" neq ".pdf" echo Usage "%0" "Quoted Text" "filename.pdf" (pdf only)&pause & exit /b
if not exist "%~2" echo Usage "%0" "Quoted Text" "filename.pdf" (PDF not found)&pause & exit /b

REM for this usage setlocal is surplus to requirement but included if needed later
rem setlocal enableExtensions enableDelayedExpansion

echo/>TempOverlay.tmp
for /f "tokens=2 delims=:."  %%c in ('ChCp') do @set "OLD_ChCp=%%~c"
if not defined OLD_ChCp set "OLD_ChCp=850"
ChCp 65001 >nul
echo/

for %%e in (
%%PDF-1.7
1 0 obj ^<^</Type/Catalog/Pages 2 0 R^>^>endobj
2 0 obj ^<^</Type/Pages/MediaBox [0 0 %Page%]/Count 1/Kids[3 0 R]^>^>endobj
3 0 obj ^<^</Type/Page/Parent 2 0 R/Resources^<^</Font^<^</F1 4 0 R^>^>^>^>/Contents 5 0 R^>^>endobj
4 0 obj ^<^</Type/Font/Subtype/Type1/BaseFont/%Font%^>^>endobj
5 0 obj ^<^</Length 72^>^>stream %Color% BT %Indent% %Elevation% TD /F1 %emSize% Tf(%~1
) do @echo %%e >>TempOverlay.tmp

@echo off
rem deliberate firebreak to allow for other additions

for %%e in (
^)Tj ET
endstream
endobj

xref
0 6
0000000000 65535 f
0000000013 00000 n
0000000071 00000 n
0000000166 00000 n
0000000281 00000 n
0000000351 00000 n
trailer^<^</Size 6/Root 1 0 R^>^>
startxref 475
%%%%EOF
) do @echo %%e >>TempOverlay.tmp

REM tidy-up temporary file
REM we expect errors from bad file above so here send error output 2 to nul
qpdf TempOverlay.tmp TempOverlay.pdf 2>nul
qpdf "%~2" --overlay TempOverlay.pdf --to=%Range% -- "%~dpn2-overlaid.pdf"

ChCp %OLD_ChCp% >nul
set OLD_ChCp=
endlocal
REM exit