[SOLVED] Extract season and episode from .vob file name to .nfo

Issue

I've been working on my first Bash script which generates .nfo files using the corresponding file names in a given directory. Using code I've found elsewhere, I've been able to achieve this and also include the following text within each .nfo file:

<episodedetails>
<title>This is working successfully</title>
<episode>This bit however is not working</episode>
<season>This bit however is not working</season>
</episodedetails>

What I'm struggling with is the Episode and Season fields within the nfo file.

My file name format is like this: Holy Bible - The Book of Ephesians (2009) - S01E01 (Introduction, Background, God's Blueprint).vob

The output of that particular nfo file (at present) is:

<episodedetails>
<title>Introduction, Background, God's Blueprint</title>
<episode>2009)</episode>
<season>The Book of Ephesians (2009)</season>
</episodedetails>

Please could you help me tweak my code so that the nfo reads:

<episodedetails>
<title>Introduction, Background, God's Blueprint</title>
<episode>01</episode>
<season>01</season>
</episodedetails>

The specific area of code that's going wrong is as follows:

episode="${filename#* - *(}"
episode="${episode% - *.vob}"

season="${filename#* - }"
season="${season% - *.vob}"

The code in its entirety:

#!/usr/bin/env bash

while IFS= read -rd '' file; do

filename="${file##*/}"

title="${filename%\).vob}"
title="${title##* (}"

episode="${filename#* - *(}"
episode="${episode% - *.vob}"

season="${filename#* - }"
season="${season% - *.vob}"

cat > "${file%\.vob}.nfo" <<< \
"<episodedetails>
<title>${title}</title>
<episode>${episode}</episode>
<season>${season}</season>
</episodedetails>"

done < <(find . -name '*.vob' -print0)

Solution

bash has a nice =~ operator of the [[ ... ]] conditional expressions that is handy in such cases. It tries to match a string (your file name) with a regular expression, and supports capture groups. The captured matches are available in the BASH_REMATCH indexed array. Example of use in your case:

while IFS= read -rd '' file; do
  [[ "$file" =~ ^.*-\ S([0-9]+)E([0-9]+)\ \((.*)\)\.vob$ ]] &&
  cat > "${file%\.vob}.nfo" <<< \
"<episodedetails>
<title>${BASH_REMATCH[3]}</title>
<episode>${BASH_REMATCH[2]}</episode>
<season>${BASH_REMATCH[1]}</season>
</episodedetails>"
done < <(find . -name '*.vob' -print0)

Answered By - Renaud Pacalet

Answer Checked By - Senaida (WPSolving Volunteer)