[SOLVED] Can a bash script extract name, version number and extension from a list of filenames

Issue

I am having trouble creating a Bash script that will extract application name, version number and possible extension from a list of filenames such as:

1. name-of-application-1-v1.2.3.AppImage
2. app-name2-V999.2.31.AppImage
3. another-application-v123.456.789
4. yet-another-example-4-V0.0.1.extA

For the above examples, the application names would be:

1. name-of-application-1
2. app-name2
3. another-application
4. yet-another-example-4

The version numbers would be:

1. 1.2.3
2. 999.2.31
3. 123.456.789
4. 0.0.1

The extensions would be:

1. "AppImage"
2. "AppImage"
3. ""
4. "extA"

All filenames have a version number preceded by v or V, but may or may not have an extension.

I have tried the following script created with the help of Google Bard:

#!/bin/bash

# Function to parse a filename and separate out the base name, version number, and extension
function parse_filename() {
    # Get the base name of the file
    basename=${1##*/}

    # Get the extension of the file
    extension=${basename##*.}

  # Remove the extension from the base name
  basename=${basename%.*}

  # Get the version number of the file
  version=${basename##*-}

  # Strip any leading or trailing spaces from the base name and version number
  basename=${basename## }
  basename=${basename%% }
  version=${version## }
  version=${version%% }

  # If the version number is not in the form digits.digits.digits, then set the version number to an empty string
  if ! [[ "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
      version=""
  fi

  # If the version number is empty, then the version number is the extension
  if [[ -z "$version" ]]; then
      version="$extension"
  fi

  # If the base name is empty, then the base name is the filename without the extension
  if [[ -z "$basename" ]]; then
      basename=${1%.*}
  fi
}

echo "Running script: $0"

# Get the list of filenames from the user
filenames=("$@")

# Iterate over the list of filenames and parse each one
for filename in "${filenames[@]}"; do
    echo "Processing filename: $filename"
    # Parse the filename and get the base name, version number, and extension
    parse_filename "$filename"

  # Print the results to the: console
  echo "Base name: $basename"
  echo "Version number: $version"
  echo "Extension: $extension"
  echo
done

This does not produce the correct output though:

Running script: ./filename-parser.sh
Processing filename: name-of-application-1-v1.2.3.AppImage
Base name: name-of-application-1-v1.2.3
Version number: 
Extension: 

Processing filename: app-name2-V999.2.31.AppImage
Base name: app-name2-V999.2.31
Version number: 
Extension: 

Processing filename: another-application-v123.456.789
Base name: another-application-v123.456
Version number: 
Extension: 

Processing filename: yet-another-example-4-V0.0.1.extA
Base name: yet-another-example-4-V0.0.1
Version number: 
Extension: 

Is this even possible in a bash script, or do I need to resort to Python, or something else.

Solution

You could use a regular expression, something like this:

#!/usr/bin/env bash

files=(
    name-of-application-1-v1.2.3.AppImage
    app-name2-V999.2.31.AppImage
    another-application-v123.456.789
    yet-another-example-4-V0.0.1.extA
)

re='(.*)-[vV](([[:digit:]]+\.){2}[[:digit:]]+)(\.(.*))?'

for file in "${files[@]}"; do
    printf 'Processing: %s\n' "$file"
    [[ $file =~ $re ]]
    printf 'Base name: %s\n' "${BASH_REMATCH[1]}"
    printf 'Version number: %s\n' "${BASH_REMATCH[2]}"
    printf 'Extension: %s\n\n' "${BASH_REMATCH[5]}"
done

Answered By - Benjamin W.

Answer Checked By - Mildred Charles (WPSolving Admin)