Text on PDF Files

As promised last time, I’m going to show a small bash script which puts text on existing pdf files. This bash script uses pdflatex, some styles and auxiliary programs to do its magic. The script is currently work in progress, thus feedback is welcome.

Once the script is placed somewhere in the path, you can apply it to any pdf document. The scripts parameters are group into three categories:

• Global parameters:

  -h

  Prints help on parameters

  -l

  Puts all boxes (see below) above any content in the pdf file. May be neccessary under certain circumstances.

  -p prefixfile

  Insert additional commands (e.g. \usepackage) into document prefix

• I/O parameters:

  -i infile

  Input file’s name

  -o outfile

  Optional argument for the output file’s name. If no name is given, the input file’s name will be used and appended by -textonpdf

• Box parameters. Boxes are text frames with coordinates (x/y), width and a textual content. Multiple boxes may be defined, each textual content will be placed at the coordinates specified in previous parameters

  -x number

  absolute x-coordinate of the next box, given in cm

  -y number

  absolute y-coordinate of the next box, given in cm

  -w number

  width of the next box, given in cm

  -t text

  textual content of the box. Occurrences of %d will be replaced by the current date, %p will be replaced with the current page’s number

  Boxes will be put on every page. The boxes’ content is centered.

Let me show you some examples:

textonpdf.sh -x 0 -y 27 -w 21 -t '%p' -i myfile.pdf -o output.pdf

will put page numbers (as given by -t '%p') centered (given a page is 21cm wide) at the bottom of each page (27cm below the top). As promised, multiple boxes may be specified. The following example puts the current date on the top of each page:

textonpdf.sh -x 5 -y 27 -w 11 -t '%p' -x 2 -w 17 -y 2 \
  -t 'File created on \textbf{%d}' -i myfile.pdf -o output.pdf

As you can see, LaTeX commands can be used in the inserted text, as the boxes’ content is directly used in the intermediate tex document. Updated: Finally, a more complex example for a watermark. First, we create a prefix file, which will be loaded using the -p switch.

\usepackage[scaled]{helvet}
\usepackage[utf8]{inputenc}
\usepackage{rotating}
\usepackage{xcolor}

These packages load Helvetica as font, set the input encoding to UTF-8 (may be different for you), and include the rotating and xcolor package. Now, we call the script:

textonpdf.sh -x 1 -y 1 -p prefix.tex -w 10 -t \
  '\centering\begin{turn}{25}\begin{minipage}{10cm}\centering\bfseries\sffamily\Huge\color{red}Nur für den\\internen Gebrauch\end{minipage}\end{turn}' \
  -i test.pdf -o test2.pdf

Here, you can two new things: First, the prefix file prefix.tex (see above) and include some tex commands into the text at the -t switch. In the text, there are commands to turn the text by 25 degrees and a minipage of 10cm widths (required for the line break later). Inside the minipage, all text is centered, set in Helvetica, huge and red. The text itself is a two lines long and warns you the document is for internal use only. Using or removing the -l switch makes a difference.

Does it work for you, too? Any bugs or comments? Let me know.

Download script