Hidden commands that can fix common problems instantly

The Philosophy of the Instant Fix: Correcting Your Previous Command with fuck / theshit

Perhaps the most quintessential example of a “hidden” command designed to instantly fix a problem is the utility known as The Fuck (and its Rust-based counterpart, theshit). This is a magnificent application that sits in your shell and waits for you to make a mistake. When a command fails due to a simple typo, forgotten sudo, or incorrect syntax, you simply type fuck (or shit / theshit depending on the version and alias you set) . The tool then analyzes the error message from the previous command, applies a series of rules, and presents you with the most likely correction.

The magic lies in its extensive, customizable rule system. For instance, if you type sl instead of ls, it will suggest the correction. If you forget sudo (e.g., mkdir /etc/project), it will prepend sudo to the command. It can handle more complex scenarios, like noticing a git typo (git biuld -> git build) or adding the -p flag to a mkdir command when the parent directory doesn’t exist . Installation and setup are straightforward, requiring you to run a setup command (like theshit setup) to create the necessary alias in your shell configuration file (.bashrc, .zshrc, etc.) . For power users, both versions allow for the creation of custom Python or native rules, giving you the ability to teach the tool how to fix your own specific, recurring mistakes . This tool transforms the frustration of a command-line error into a near-instantaneous, often humorous, fix.

Windows System Recovery: The Power Duo of DISM and SFC

On the Windows operating system, when the system becomes unstable, applications crash, or files become corrupted, two “hidden” command-line tools serve as the primary line of defense: Deployment Imaging Service and Management (DISM) and System File Checker (SFC) . These are not just simple commands; they are a diagnostic and repair hierarchy that can resolve deep-seated system issues. The process almost always begins with an elevated Command Prompt—you must search for “Command Prompt” or “PowerShell,” right-click it, and select “Run as administrator” .

The recommended sequence starts with DISM /Online /Cleanup-Image /RestoreHealth . This command scans the Windows image for corruption and, by default, connects to Windows Update to download clean copies of any corrupted files to replace the damaged ones. This process can take a significant amount of time (often 15-20 minutes or more) and requires a stable internet connection . Following a successful DISM repair, the next command is sfc /scannow. This tool specifically scans all protected system files and replaces incorrect or corrupted versions with the correct versions that were just repaired by DISM . Together, these commands form a powerful one-two punch: DISM repairs the component store (the source of system files), and SFC then uses that clean source to repair the installed system files. Tools like the Windows Repair Tool bundle these operations into a sequential repair mode, ensuring they run in the optimal order for maximum effectiveness .

Windows Troubleshooters: Direct Access from the Command Line

Windows 10 and 11 come with a suite of graphical troubleshooters for diagnosing and fixing specific problems like network issues, printer errors, or audio failures. While users typically navigate through the Settings app to find them, a hidden method exists to launch them instantly from the command line using their unique identifiers. By opening a Command Prompt or PowerShell window, you can type msdt.exe /id [Diagnostic_Identifier] to launch a specific troubleshooter directly .

This method provides a rapid shortcut to the exact tool you need. For example, to fix internet connection problems, you would run msdt.exe /id NetworkDiagnosticsWeb. For persistent Windows Update failures, the command is msdt.exe /id WindowsUpdateDiagnostic. Other useful identifiers include DeviceDiagnostic for hardware issues, AudioPlaybackDiagnostic for sound problems, and PerformanceDiagnostic for a general system health check . Furthermore, you can use URI shortcuts to jump directly to relevant Settings pages, such as typing ms-settings:troubleshoot to open the main Troubleshoot settings page . These commands bypass the menu navigation, allowing for faster and more direct system repair.

Linux Network and System Rescue: Underrated Diagnostic Commands

In the Linux world, several underappreciated commands can provide instant insights and fixes for system problems. For boot-time issues, systemd-analyze is an invaluable tool. Simply running systemd-analyze gives you a summary of the total boot time. To find out what is slowing down your system, you can run systemd-analyze blame, which prints a list of all running services, ordered by the time they took to start during the boot process . This instantly pinpoints the culprit behind a slow startup. For an even more granular view, you can generate a visual timeline of the entire boot process with systemd-analyze plot > boot.svg and open the resulting SVG file in a web browser to see a graphical representation of service start times and dependencies .

For everyday system interaction, commands like pv (Pipe Viewer) add instant visibility to long-running operations. Instead of watching a cursor blink while copying a large file with cp, you can use pv large_file.iso > /destination/folder/large_file.iso to see a progress bar, current speed, and estimated time remaining . Another lifesaver is the timeout command, which allows you to run a command for a specified duration and then automatically kill it. For example, timeout 10s ping google.com will ping Google for only 10 seconds and then stop, which is incredibly useful for testing or for commands that might hang indefinitely .

Linux File and Text Manipulation: Commands for Everyday Efficiency

A set of “hidden” commands also excels at instantly manipulating text and files, fixing common data-handling problems. The rename command, often more powerful than its GUI counterparts, can bulk-rename files using Perl expressions. For instance, to change the extension of every .txt file in a folder to .log, you would use rename 's/\.txt$/\.log/' *.txt. It can also handle more complex tasks like converting all filenames to lowercase (rename 'y/A-Z/a-z/' *) or adding prefixes to files .

When dealing with log files or comparing data, tac (the reverse of cat) instantly reverses the order of a file, printing the last line first. This is perfect for quickly checking the most recent entries in a log file with tac /var/log/syslog | less . For comparing two sorted files, the comm command provides a three-column output showing lines unique to the first file, lines unique to the second file, and lines common to both. Using flags like -12 suppresses these columns, allowing you, for instance, to show only the lines common to both files with comm -12 file1.txt file2.txt . These commands, while simple, offer powerful and instant solutions for what would otherwise be tedious manual editing tasks.