Mastodawn

R.L. Dane

🍵

Apr 16

tired: ls |wc -l
wired: c=0; for x in *; do ((c++)); done; echo $c
inspired: whatever @mirabilos suggests 😄

#UnixShell #avoiding_the_dreaded_fork()

R.L. Dane

🍵

Apr 16

Highest system load I've seen (while the system was still responsive, that is):

Thu Apr 16 05:02:25 PM CDT 2026 83.95 (6.995 per processor (12))

Was batch converting ~250 jpegs into avif, running 16 processes concurrently.
#UnixShell makes it stupidly easy. :D

(hint: ncpus=$(lscpu -bp |grep -c "^[0-9]"); while (( $(jobs) >= ncpus )); do sleep 1; done ;)

R.L. Dane

🍵

Apr 12

Something that I'd love to be able to do, but haven't figured out how, yet:

You can run somecommand 2>&1 > log.txt to get STDOUT and STDERR together, but you won't know which is which.
You can run somecommand 2>err.txt >log.txt to get STDOUT and STDERR separate, but you won't know the timing, or which error messages happened between which STDOUT messages.
I'd like to figure out some way to combine both, so you end up with a file like this:

1: this was a STDOUT message
1: this was a STDOUT message
1: this was a STDOUT message
2: this was a STDERR message
2: this was a STDERR message
1: this was a STDOUT message
2: this was a STDERR message
1: this was a STDOUT message
1: this was a STDOUT message
1: this was a STDOUT message
1: this was a STDOUT message
1: this was a STDOUT message
2: this was a STDERR message
2: this was a STDERR message

Any ideas? @mirabilos?

#Unix #UnixShell #Linux #BSD

R.L. Dane

🍵

Apr 10

Wrote a #shell function without using ls inside of $( ), so my inner @mirabilos won't harass me. XD

#slightly easier wireguard command
function wg {
    local dir file profile profiledir= parm=${1:-} statustext
    #Find profile dir
    for dir in {,/usr/local}/etc/wireguard; do
        if [[ -d $dir ]]; then
            profiledir=$dir
            break
        fi
    done
    #Find config file
    if [[ -n $profiledir ]]; then
        for file in $profiledir/*.conf; do
            if [[ -e $file ]]; then
                profile=${file//*\/}
                profile=${profile/.conf}
                break
            fi
        done
    fi
    [[ -n $profile ]] || profile=proton
    statustext="wireguard profile $profile"
    case ${parm,,} in
        up|on)      doas wg-quick  up  $profile;;
        down|off)   doas wg-quick down $profile;;
        status)     echo -en "$statustext _______\r"
                    echo -en "$statustext "
                    ifconfig |grep -q "^$profile:" && echo enabled || echo disabled;;
        *)          warn "wg usage: wg up|down|status";;
    esac
}

Hmm, seems ${foo,,} for lower case conversion is #bash-only. I wonder if I should use tr instead.

#Unix #UnixShell #ShellScript #ShellScripting

R.L. Dane

🍵

Apr 2

I'm not saying you should all go out and set up aliases to enable your various typos and slip-ups, but I honestly don't know why I didn't do this 25 years ago.

alias cd..='cd ..'

#bash #UNIX #Shell #UnixShell #POSIX

R.L. Dane

🍵

Mar 29

Recursion usually scares me a bit, but it worked out nicely here:

#convert "cx"-style Esperanto notation to native accents (ĉ)
function eaccent {
    if [[ ${1:-} ]]; then
        echo "$*" |eaccent
    else
        sed 's/cx/ĉ/g; s/gx/ĝ/g; s/hx/ĥ/g; s/jx/ĵ/g; s/sx/ŝ/g; s/ux/ŭ/g; s/C[xX]/Ĉ/g; s/G[xX]/Ĝ/g; s/H[xX]/Ĥ/g; s/J[xX]/Ĵ/g; s/S[xX]/Ŝ/g; s/U[xX]/Ŭ/g'
    fi
}

#bash #unix #shell #scripts #scripting #UnixShell #ShellScripting #Esperanto

justsoup

Mar 19

Quick tip if you ever need to add a linebreak to the end of a file manually for whatever reason, `echo >> filename` works.

#Linux #Shell #UnixShell #LinuxShell #Bash

Ethan Black Feb 16

When you're dealing with plaintext data in a suspicious context, consider using `cat -v` where you'd usually use `cat`.

```
-v, --show-nonprinting
use ^ and M- notation, except for LFD and TAB
```

#UnixShell #commandLine #Linux #LinuxTips #cybersecurity

R.L. Dane

🍵

Feb 4

File this under #shell #functions I should have written years ago:

function grepc {
    #Do a grep -c, but skipping files with no results
    grep -c "$@" |grep -v ':0$'
}

#unix #UnixShell #ShellScripting #bash #ksh

P.S., the body of the parent #toot was created by a simple #shell #function:

function apod {
    #Today's NASA Astronomy Picture of the Day info-fetcher
    curl -sL 'https://apod.nasa.gov/apod/archivepix.html' \
        |grep -m1 "[0-9][0-9]:" \
        |sed 's/^/Date: /;
            s|: *<a href="|\nURL: https://apod.nasa.gov/apod/|;
            s/">/\nTitle: /; s/<.*$//'
    echo
    echo "#NASA #Astronomy #PictureOfTheDay"
}

#bash #ksh #mksh #shellScripting #unix #UnixShell #WebScraping #Scraping #HTML