replace-text-pdf

Replaces text occurrences within pdf files.
A trickier task than you might suppose...made easy-er here, and possible to script via the command line.

To use:

convert your pdf to "uncompressed" format. pdftk is one way https://stackoverflow.com/a/920471/32453

$ sudo apt install pdftk $ pdftk original.pdf output original.uncompressed.pdf uncompress

Now at this point, your raw pdf file might well have some text in it that looks wonky, like this syntax for the text "Other information ":

[(O)-16(ther i)-20(nformati)-11(on )]TJ

The weird numbers denote text offsets, allowing for kerning and controlling the size of the spaces between words and such https://stackoverflow.com/a/66282749/32453, and appear to be common. But make it hard to use a tool like "sed" to modify text.

So this program is "TJ aware"'ish, you tell it which text to replace. If it finds it, it discards the glyph numbers and does the replace.
It works most of the time. More often than sed typically. At least as good at sed always (assuming you don't need regular expression replace). Give it a shot!

To run it, install "crystal" programming language compiler first then clone this repo. Then cd into it, run

$ make

or

$ crystal build replaceinpdf.cr

now run the program like:

$ ./replaceinpdf.cr input_filename.pdf "something you want replaced" "what you want it replaced with" output_filename.pdf

output_filename.pdf can be the input filename if you'd like to overwrite it with the modified file.
input and output filenames can be "-" if you want to output to stdout (ex: chain for multiple subsequent replacements)

For instance $ ./replaceinpdf input.pdf "this" "with that" - | ./replaceinpdf - "this2" "with that2" final_output.pdf

Or another way to do it:

$ cp myinput.pdf munged.pdf $ ./replaceinpdf munged.pdf "this" "with that" munged.pdf $ ./replaceinpdf munged.pdf "this2" "with that2" munged.pdf

Or a bash script to wrap it/do the same might look like this (named "rewrite_lots.sh" or what have you):

#!/usr/bin/env bash go() { # params: replace this, with that ./replaceinpdf utah.2021.pdf "$1" "$2" utah.2021.pdf }

cp utah.uncompressed.pdf utah.2021.pdf

go "my original stuff" "replace that with this new thing" go 4.56 7.32 go "more stuff" "replace with this stuff" ...

By default it replaces "all occurrences" of "this" with "that". If you want to replace only "one occurrence" or a "specific occurrence" of a particular string, run it like ./replaceinpdf filename.pdf "fake" "fake" fake.pdf just_print_line_numbers

It'll spit out an enumerated list of all text lines in that pdf. Figure out/grab the number of the specific text you want to replace, then run it with that number like this: ./replaceinpdf filename.pdf "replace this" "with this" output.pdf 23456 # 23456 is the line number for it to replace on, all else is left same.

Limitations: only replaces text within a single line.

Might lose some formatting, your mileage may vary. Basically today if you were to replace the word "information" with "info" in our example it would convert [(O)-16(ther i)-20(nformati)-11(on )]TJ to just [Other info ]TJ Which may or may not be what you want, since it loses the spacing numbers, but lines up OK most times. If you happen to replace text that is contained in a single element, it will retain the spacing info for it. ex: replace "format" with "ZZ" in above example changes it to [(O)-16(ther i)-20(nZZi)-11(on )]TJ which usually works well. One trick that might work (if this gets spacing wrong) in the meantime is to add spaces like replace "x" with " x" to move it right a bit.

Feedback/bugs/feature requests welcome via github issues. More features possible: keeping the exact formatting only if the text is the "same exact size"

Contributing: run existing specs like $ crystal spec Submit a PR or issue :)

Related: you can also replace text manually in Pdfs using openoffice draw or inkscape.

You can change the "title" that shows up in the browser when you view a pdf using a different tool, sed: sed -i 's/old title/new title/' filename.pdf

Cheers!