Decrypt many PDFs in one go using pdftk - unix

Question

I have 10 PDFs that ask for a user password to open. I know that password. I want to keep them in a decrypted format. Their filenames follow the form:
static_part.dynamic_part_like_date.pdf
I want to convert all the 10 files. I can give a * after the static part and work on all of them, but I also want the corresponding output filenames. So there has to be a way to capture the dynamic part of the filename and then use it in the output filename.
The normal way of doing this for one file is:
pdftk secured.pdf input_pw foopass output unsecured.pdf
I want to do something like:
pdftk var=secured*.pdf input_pw foopass output unsecured+var.pdf
Thanks.

Answer 1

Your request is a little ambiguous, but here are some ideas that might help you.
Assuming 1 of your 10 files is
# static_part.dynamic_part_like_date.pdf
# SalesReport.20110416.pdf (YYYYMMDD)
And you want only the SalesReport.pdf converted as unsecured, you can use a shell script to achieve your requirement:
# make a file with the following contents,
# then make it executable with `chmod 755 pdfFixer.sh`
# the .../bin/bash has to be the first line the file.
$ cat pdfFixer.sh
#!/bin/bash
# call the script like $ pdfFixer.sh staticPart.*.pdf
# ( not '$' char in your command, that is the cmd-line prompt in this example,
# yours may look different )
# use a variable to hold the password you want to use
pw=foopass
for file in ${#} ; do
# %%.* strips off everything after the first '.' char
unsecuredName=${file%%.*}.pdf
#your example : pdftk secured.pdf input_pw foopass output unsecured.pdf
#converts to
pdftk ${file} input_pw ${foopass} output ${unsecuredName}.pdf
done
You may find that you need to modify the %.* thing to
strip less from end, (use %.*) to strip just the last '.' and all chars after (strip from right).
strip from the fron (use #*.) to just the static part, leaving the dynamic part OR
strip from the front (use ##*.) to strip everything until the last '.' char.
It will really be much easier for you to figure out what you need at the cmd-line.
Set a variable with 1 sample fileName
myTestFileName=staticPart.dynamicPart.pdf
and then use echo combined with the variable modifiers to see the results.
echo ${myTestFileName##*.}
echo ${myTestFileName#*.}
echo ${myTestFileName##.*}
echo ${myTestFileName#.*}
echo ${myTestFileName%%.*}
etc.
Also notice how I combine a modified variable value with a plain string (.pdf), in unsecuredName=${file%%.*}.pdf
IHTH