Using itextsharp (or any c# pdf library), how to open a PDF, replace some text, and save it again?

Question

Using itextsharp (or any c# pdf library), i need to open a PDF, replace some placeholder text with actual values, and return it as a byte[].

Can someone suggest how to d

Answer 1

I have a python script here that replaces some text in a PDF:

import re
import sys
import zlib

# Module to find and replace text in PDF files
#
# Usage:
#   python pdf_replace.py    
#
# @author Ionox0

input_filename = sys.argv[1]
text_to_find = sys.argv[2]
text_to_replace = sys.argv[3]
output_filename sys.argv[4]

pdf = open(input_filename, "rb").read()

# Create a copy of the PDF content to make edits to
pdf_copy = pdf[0:]

# Search for stream objects with text to replace
stream = re.compile(r'.*?FlateDecode.*?stream(.*?)endstream', re.S)

for s in stream.findall(pdf):
    s = s.strip('\r\n')

    try:
        text = zlib.decompress(s)

        if text_to_find in text:
            print('Found match:')
            print(text)

            text = text.replace(text_to_find, text_to_replace)
            pdf_copy = pdf_copy.replace(s, zlib.compress(text))
    except:
        pass

with open(output_filename, 'wb') as out:
    out.write(pdf_copy)