I’ve been setting up a new Proxmox server and messing around with VMs, and wanted to know what kind of useful commands I’m missing out on. Bonus points for a little explainer.

Journalctl | grep -C 10 'foo' was useful for me when I needed to troubleshoot some fstab mount fuckery on boot. It pipes Journalctl (boot logs) into grep to find ‘foo’, and prints 10 lines before and after each instance of ‘foo’.

  • harsh3466@lemmy.ml
    6·
    10 hours ago
    find /path/to/starting/dir -type f -regextype egrep -regex 'some[[:space:]]*regex[[:space:]]*(goes|here)' -exec mv {} /path/to/new/directory/ \;

    I routinely have to find a bunch of files that match a particular pattern and then do something with those files, and as a result, find with -exec is one of my top commands.

    If you’re someone who doesn’t know wtf that above command does, here’s a breakdown piece by piece:

    • find - cli tool to find files based on lots of different parameters
    • /path/to/starting/dir - the directory at which find will start looking for files recursively moving down the file tree
    • -type f - specifies I only want find to find files.
    • -regextype egrep - In this example I’m using regex to pattern match filenames, and this tells find what flavor of regex to use
    • -regex 'regex.here' - The regex to be used to pattern match against the filenames
    • -exec - exec is a way to redirect output in bash and use that output as a parameter in the subsequent command.
    • mv {} /path/to/new/directory/ - mv is just an example, you can use almost any command here. The important bit is {}, which is the placeholder for the parameter coming from find, in this case, a full file path. So this would read when expanded, mv /full/path/of/file/that/matches/the/regex.file /path/to/new/directory/
    • \; - This terminates the command. The semi-colon is the actual termination, but it must be escaped so that the current shell doesn’t see it and try to use it as a command separator.