csplit multiple files into multiple files

Question

folks-

I'm a bit stumped, on this one. I'm trying to write a bash script that will use csplit to take multiple input files and split them according to the same pattern. (For context: I have multiple TeX files with questions in them, separated by the \question command. I want to extract each question into their own file.)

The code I have so far:

#!/bin/bash
# This script uses csplit to run through an input TeX file (or list of TeX files) to separate out all the questions into their own files.
# This line is for the user to input the name of the file they need questions split from.

read -ep "Type the directory and/or name of the file needed to split. If there is more than one file, enter the files separated by a space. " files

read -ep "Type the directory where you would like to save the split files: " save

read -ep "What unit do these questions belong to?" unit

# This is a check for the user to confirm the file list, and proceed if true:

echo "The file(s) being split is/are $files. Please confirm that you wish to split this file, or cancel."
select ynf in "Yes" "No"; do
    case $ynf in 
        No ) exit;;
        Yes ) echo "The split files will be saved to $save. Please confirm that you wish to save the files here."
            select ynd in "Yes" "No"; do
            case $ynd in
                Yes )
#                   This line will create a loop to conduct the script over all the files in the list.
                    for i in ${files[@]}
                    do
#                   Mass re-naming is formatted to give "guestion###.tex' to enable processing a large number of questions quickly.
#                   csplit is the utility used here; run "man csplit" to learn more of its functionality.
#                   the structure is "csplit [name of file] [output options] [search filter] [separator(s)].
#                   this script calls csplit, will accept the name of the file in the argument, searches the files for calls of "question", splits the file everywhere it finds a line with "question", and renames it according to the scheme [prefix]#[suffix] (the %03d in the suffix-format is what increments the numbering automatically).
#                   the '\\question' allows searching for \question, which eliminates the split for \end{questions}; eliminating the \begin{questions} split has not yet been understood.
                        csplit $i --prefix=$save'/'$unit'q' --suffix-format='%03d.tex' /'\\question'/ '{*}'
                    done; exit;;
                No ) exit;;
            esac
        done
    esac
done

return

I can confirm it does do the loop as I intended for the input files I have. However, the behavior I'm noticing is that it'll split the first file into "q1.tex q2.tex q3.tex" as expected, and when it moves on to the next file in the list, it'll split the questions and overwrite the old files, and the third file it will overwrite the second file's splits, etc. What I would like to happen is that, say, if File1 has 3 questions, it will output:

q1.tex
q2.tex
q3.tex

And then if File2 has 4 questions, it will then continue incrementing to:

q4.tex
q5.tex
q6.tex
q7.tex

Is there a way for csplit to detect the numbering that has already been done in this loop, and increment appropriately?

Thanks for any help you folks can offer!

Answer 1

The csplit command has no saved context (and nor should it), so it always starts its counting from 1. There's no way to fix this, but you could maintain your own counted value that you interpolate into the prefix string.

Alternatively, try replacing

read -ep "Type the directory and/or name of the file needed to split. If there is more than one file, enter the files separated by a space. " files

...

for i in ${files[@]}
do
    csplit $i --prefix=$save'/'$unit'q' --suffix-format='%03d.tex' /'\\question'/ '{*}'
done

with

read -a files -ep 'Type the directory and/or name of the file needed to split. If there is more than one file, enter the files separated by a space. '

...

cat "${files[@]}" | csplit - --prefix="$save/${unit}q" --suffix-format='%03d.tex' '/\\question/' '{*}'

This is one of the relatively rare instances where one really does need to use cat {file} | ... as csplit takes only a single file argument (or - for stdin).

I've changed your read action to use an array variable since that's what you are (correctly) trying to use in your for ... do csplit ... loop.

Regardless of what you finally decide to do, I'd strongly recommend you double-quote all your variables where you use them, particularly any further use of an array list such as "${files[@]}".

Answer 2

With Awk you could run something along the lines of:

awk '/\\question/ {i++} ; {print > "q" i ".tex"}'  exam*.tex

If you want to define out-dir(d) and topic(t), and control the number length:

awk '/\\question/ {f=sprintf("%s/%s-q%03d.tex", d, t, i++)} {print>f}' d=d1 t=t1 ex*

In order to skip TeX preambulo, we can "print" just when "f" is defined:

awk '/\\question/ {f=sprintf("%s/%s-q%03d.tex", d, t, ++i)} 
     f            {print>f}' d=d1 t=t1 ex*

Answer 3

You can use this script

grep -o -P '(parameter).*(parameter)' your_teX_file.teX > questions.txt

you get questions.txt file for all questions then you can split it.

split -l 1 questions.txt