Which Linux command or utility is simple, powerful, and surprisingly unknown to many people or used less often?

This could be a command or a piece of software or an application.

For example I’m surprised to find that many people are unaware of Caddy, a very simple web server that can make setting up a reverse proxy incredibly easy.

Another example is fzf. Many people overlook this, a fast command-line fuzzy finder. It’s versatile for searching files, directories, or even shell history with minimal effort.

  • @[email protected]
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    112 days ago

    socat - connect anything to anything

    for example

    socat - tcp-connect:remote-server:12345

    socat tcp-listen:12345 -

    socat tcp-listen:12345 tcp-connect:remote-server:12345

  • @friend_of_satan
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    3 days ago

    Not powerful, but often useful, column -t aligns columns in all lines. EG

    $ echo {a,bb,ccc}{5,10,9999,888} | xargs -n3
    a5 a10 a9999
    a888 bb5 bb10
    bb9999 bb888 ccc5
    ccc10 ccc9999 ccc888
    $ echo {a,bb,ccc}{5,10,9999,888} | xargs -n3 | column -t
    a5      a10      a9999
    a888    bb5      bb10
    bb9999  bb888    ccc5
    ccc10   ccc9999  ccc888
    
  • @[email protected]
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    2 days ago

    nmap *your_local_ip_address*

    for example

    nmap 192.168.1.43/24 will show you what devices are connected to the local network, and what ports are open there. really useful, for example, when you forgot the address of your printer or raspi yet again.

    you can also use it to understand what ports on your computer are open from an attacker’s perspective, or simply to figure out what services are running (ssh service).

  • jollyroberts
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    363 days ago

    Control+r == search through your bash history.

    I used linux for ten years before finding out about that one.

  • @[email protected]
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    32 days ago

    losetup

    it’s useful for dealing with virtual disk images. like a real physical hard disk, but it’s a file on the computer. you can mount it, format it, and write it to a real physical disk.

    it’s sometimes used with virtual machines, with iso images, or when preparing a bootable disk.

  • PatchworkHorse
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    444 days ago

    jq - super powerful json parser. Useful by hand and in scripts

    • @friend_of_satan
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      63 days ago

      I love jq, but I wouldn’t call it “surprising simple” for anything but pretty-formatting json. It has a fairly steep learning curve for doing anything with all but the simplest operations on the simplest data structures.

    • qaz
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      3 days ago

      It can also format minimized JSON from cURL API requests

    • @[email protected]
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      33 days ago

      Combine with jc to process CSV files. This is how I get data into my plain text accounting system.

  • @[email protected]
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    964 days ago

    I think a lot of people don’t realise that yt-dlp works for many sites, not just YouTube

    I used it recently for watching a video from tiktok without having to use their god awful web UI and it was amazing

  • Count Regal Inkwell
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    3 days ago

    batcat

    It’s like cat but better. Great for when you just want to look at the contents of a file, without loading a whole text editor.

    Oh also, tldr

    My procedure for learning how to use a cli command goes tldr page -> --help if the tldr fails to help me -> THEN the full manpage

  • DigitalDilemma
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    253 days ago

    yes

    The most positive command you’ll ever use.

    Run it normally and it just spams ‘y’ from the keyboard. But when one of the commands above is piped to it, then it will respond with ‘y’. Not every command has a true -y to automate acceptance of prompts and that’s what this is for.

    • @friend_of_satan
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      103 days ago

      Also, you can make yes return anything:

      yes no
      
    • @alvendam
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      23 days ago

      What’s the syntax here? Do I go

      command && yes

      I’m not sure if I’ve had a use case for it, but it’s interesting.

      • @valkyre09
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        103 days ago

        Also my favourite way to push a core to 100% CPU

        yes > /dev/null
        
          • @valkyre09
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            32 days ago

            Who said it was better? It’s just my favourite.

            Like my favourite shirt, it’s no better than the others, but it brings me a little joy :)

            • on a serious note though, thank you for sharing your two examples - I didn’t know they existed.
      • @[email protected]
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        103 days ago

        That will just wait for command to finish properly and then run yes.

        What you want to run is yes | command, so it spams the command with confirmations.

      • @[email protected]
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        3 days ago

        true delivers error level 0, false error level 1.

        yes && echo True || echo False will always be True.

        false && echo True || echo False will always be False.

        Common usage is for tools that ask for permissions and similiar. yes | cp -i has the same effect as cp --force (-i: prompt before overwrites).

      • DigitalDilemma
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        3 days ago

        Sorry, I should have explained that. it’s command | yes yes|command - Eg, yes|apt-get update (Not a great example since apt-get has -y, but sometimes that fails when prompting for new keys to accept)

        Edit: I got it backwards, thanks @[email protected] for the correction.

        • @[email protected]
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          93 days ago

          You’ve got it backwards - you need to pipe the output of yes into the input of the command:

          yes | command-that-asks-a-lot-of-questions
          
      • @markstos
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        13 days ago

        For some cases I use “|| true”.

        The idiom accepts that the preceding command might fail, and that’s OK.

        For example, a script where mkdir creates a directory that might already exist.