How to use the command 'fselect' (with examples)

The command ‘fselect’ is a tool that allows users to find files using SQL-like queries. It provides a flexible and powerful way to search for specific files based on different criteria such as file name, size, genre, bitrate, etc. This article provides several examples of how to use the ‘fselect’ command in different scenarios.

Use case 1: Select full path and size from temporary or config files in a given directory

Code:

fselect size, path from path/to/directory where name = '*.cfg' or name = '*.tmp'

Motivation: This example is useful when you need to find temporary or configuration files in a specific directory and gather information about their size and location. It can be helpful for managing and cleaning up temporary files or identifying configuration files that are no longer needed.

Explanation:

• size, path: Specifies the fields to be selected (full path and size).
• from path/to/directory: Specifies the directory to search for files.
• where name = '*.cfg' or name = '*.tmp': Specifies the condition for file name. In this case, it searches for files with either ‘.cfg’ or ‘.tmp’ extension.

Example output:

  size       |       path       
-------------+-----------------
  10624      | /path/to/file.tmp
  5981       | /path/to/config.cfg
  932        | /path/to/config.tmp

Use case 2: Find square images

Code:

fselect path from path/to/directory where width = height

Motivation: This use case is suitable for finding square images in a specific directory. It can be useful for filtering and organizing images based on their dimensions, particularly when dealing with a large collection of images.

Explanation:

• path: Specifies the field to be selected (file path).
• from path/to/directory: Specifies the directory to search for files.
• where width = height: Specifies the condition for square images. It searches for images where the width and height are equal.

Example output:

       path        
--------------------
 /path/to/image1.jpg
 /path/to/image2.png

Use case 3: Find old-school rap 320kbps MP3 files

Code:

fselect path from path/to/directory where genre = Rap and bitrate = 320 and mp3_year lt 2000

Motivation: This example is useful when searching for old-school rap music files encoded in 320kbps MP3 format in a specific directory. It can be helpful for creating playlists or organizing music collections based on genre, quality, and release year.

Explanation:

• path: Specifies the field to be selected (file path).
• from path/to/directory: Specifies the directory to search for files.
• where genre = Rap and bitrate = 320 and mp3_year lt 2000: Specifies the conditions for genre, bitrate, and release year. It searches for files with genre ‘Rap’, bitrate 320kbps, and released before the year 2000.

Example output:

          path           
-------------------------
 /path/to/track1.mp3 
 /path/to/track2.mp3 
 /path/to/track3.mp3 

Use case 4: Select only the first 5 results and output as JSON

Code:

fselect size, path from path/to/directory limit 5 into json

Motivation: This use case is helpful when you want to limit the number of results and output them in a machine-readable format such as JSON. It can be useful for scripting or integrating the output with other tools or processes.

Explanation:

• size, path: Specifies the fields to be selected (full path and size).
• from path/to/directory: Specifies the directory to search for files.
• limit 5: Specifies that only the first 5 results should be returned.
• into json: Specifies the output format as JSON.

Example output:

[
    {
        "size": 10624,
        "path": "/path/to/file1.txt"
    },
    {
        "size": 5981,
        "path": "/path/to/file2.txt"
    },
    {
        "size": 932,
        "path": "/path/to/file3.txt"
    }
]

Use case 5: Use SQL aggregate functions to calculate minimum, maximum and average size of files in a directory

Code:

fselect "MIN(size), MAX(size), AVG(size), SUM(size), COUNT(*) from path/to/directory"

Motivation: This example is useful when you need to gather statistical information about file sizes in a specific directory, such as the minimum, maximum, average, total size, and count of files. It can be helpful for analyzing storage usage or identifying outliers in file sizes.

Explanation:

• "MIN(size), MAX(size), AVG(size), SUM(size), COUNT(*)": Specifies the SQL aggregate functions to calculate minimum, maximum, average, sum, and count on the ‘size’ field.
• from path/to/directory: Specifies the directory to search for files.

Example output:

 min   | max   | avg           | sum       | count 
-------+-------+---------------+-----------+-------
 932   | 150924| 35887.3226    | 184579258 | 5146

Conclusion:

The ‘fselect’ command provides a powerful and flexible way to search for files using SQL-like queries. It can be useful in various scenarios, including managing files, organizing file collections, gathering statistics, and automating file-related tasks. By leveraging its querying capabilities, users can efficiently find specific files and extract relevant information based on their needs.