Optimize your workflow: Command-line utilities for efficient task automation

Command-line-utilities-leuven is a collection of useful Shell scripts and command-line tools that can simplify and automate tasks on the command line. From file manipulation to system administration, these scripts cover a wide range of tasks and can save you time and effort in your daily workflow. Whether you’re a seasoned command-line user or just getting started, this repository has something for everyone.

“Running XXX. This may take some time… done.”

Requirements

To be able to use the following commands, ensure that the following package is installed on your system.

• docopts (docopt for shell – make beautiful CLI with ease)

  (I choose for the “with grep” syntax to have the help and version messages parsed from script comments, while avoiding having to source docopts.sh.)

• wsl repository (for bin/docopts, needed in a WSL environment)

Commands

bak

Create a quick back-up copy of a file.

f

Find directories or files matching a string and print their full file name.

fd

Find directories matching a string and print their full file name.

ff

Find files matching a string and print their full file name.

find-duplicate-filenames

Find files with duplicate or conflicting names.

find-duplicate-files

Search for duplicated files.

find-recently-modified-files

Find all files modified in the last 7 days (including today).

find-today-files

Find all files modified today in a specified directory or the current directory (if none is specified), with the option to filter by file extension.

remove-matching-lines-between-files

Remove lines that match any lines between two files.

uncolor

Strip color sequences from the input text.

swap

Swap the contents of two files.

time-run-command-100

Run a command 100 times and print its average and median execution time.

Contribute to the project!

Best Practices

Bash scripting can be a powerful tool for automating tasks, but it’s important to follow best practices to ensure that your scripts are efficient, reliable, and maintainable. Here are some best practices to keep in mind:

• Use /usr/bin/env bash in the shebang line (more portable way to reference the Bash interpreter).
• Use comments to explain what the code does.
• Use variables to store values used multiple times.
• Rename variables to follow lowercase naming convention.
• Enclose variables in double quotes to prevent word splitting and globbing.
• Use functions to avoid code repetition.
• Use set -u to treat unset variables as errors.
• Use set -e to exit immediately if a command fails.
• Use set -o pipefail to exit if any command in a pipeline fails.
• Use exit codes to indicate success or failure.
• Use printf instead of echo for better control over the output format.
• Add a period to the end of the error messages, so that it follows grammatical conventions.
• Use grep with the -w flag to match whole words.
• Use cut instead of awk to extract strings.
• Use uniq -d to find duplicated strings.
• Use sort -u to sort the output and remove duplicates from a list (instead of sort | uniq).
• Use $() instead of backticks for command substitution.
• Use double brackets ([[ ... ]]) in Bash and Zsh scripting for more advanced conditional expressions, improved handling of variables (allows unquoted variables and word splitting), enhanced logical operators (&&, ||), and built-in pattern matching, providing a more powerful and flexible approach to conditionals compared to single brackets ([ ... ]).
• Use uppercase letters for variables that are intended to be constants and not changed during the script execution.
• Use lowercase letters for regular variables that can be modified during the script execution.

By following these best practices, you can write Bash scripts that are easier to understand, maintain, and debug.

Naming convention: path or directory?

If your script specifically requires a directory path and you want to avoid ambiguity, DIRECTORY is a clearer choice.

If your script needs to accept both file and directory paths and you want to keep the argument name more general, PATH might be more suitable.

Find – Excluding Git directories and files

To exclude Git directories and files,

find "$DIRECTORY" -type f -not -path "*/.git/*" -printf "%f\n"
find "$DIRECTORY" -type d -name .git -prune -o -type f -printf "%f\n"

the second option with the -prune action is generally better and more efficient.

The -prune action stops find from descending into .git directories, making it more efficient as it avoids unnecessary checks within these directories.

Notes

Writing a Bash script in functions can make the code easier to reuse, more readable, and easier to test and debug, which can save time and reduce the likelihood of errors.

See https://unix.stackexchange.com/questions/313256/why-write-an-entire-bash-script-in-functions

Code style

• Beautiful Bash: Let’s make reading and writing bash scripts fun again! https://fr.slideshare.net/a_z_e_t/inpresentation
• Let’s make better scripts https://downloads.cisofy.com/files/public/presentation-lets-make-better-scripts.pdf
• http://wiki.bash-hackers.org/scripting/style
• https://github.com/azet/community_bash_style_guide
• https://google-styleguide.googlecode.com/svn/trunk/shell.xml

  variable_name (preferred, variableName accepted)
  function_name \ CONSTANT_NAME

Shell formatter + checker

• https://github.com/mvdan/sh
• https://google.github.io/styleguide/shell.xml
• https://www.shellcheck.net/ (online checker!)

http://www.skybert.net/emacs/bash-linting-in-emacs/

Report issues and enhancements

Found a bug or have an idea for a new feature? Share your thoughts on the GitHub issue tracker.

Submit patches

I welcome contributions in any form! Feel free to submit patches to enhance the project.

Support development with a donation!

If you find the “command-line-utilities-leuven” project (or any of my other projects) enhancing your Shell experience and simplifying your workflow, seize the opportunity to express your appreciation! Help fuel future development by making a donation through PayPal. Your support is invaluable – thank you!

Remember, regardless of donations, “command-line-utilities-leuven” will always remain freely accessible, both as in Belgian beer and as in speech.

License

Copyright (C) 2012-2024 Fabrice Niessen

Author: Fabrice Niessen
Keywords: command-line utilities scripts

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.