Commands by kostis (3)

  • Converts all pngs in a folder to webp using all available cores

    As an alternative to the above command, this one ditches the unnecessary and complicated for loop in favor of a way faster multi-core approach for a task that's more CPU than I/O intensive, making it a perfect suite for GNU parallel


    4
    parallel cwebp -q 80 {} -o {.}.webp ::: *.png
    kostis · 2018-12-07 23:37:24 1
  • quick integer CPU benchmark

    You could have that little benchmark run on all cores in parallel, as a multi-core benchmark or stress test First find the number of cores, then have parallel iterate over that in, well, parallel Show Sample Output


    -1
    time cat /proc/cpuinfo |grep proc|wc -l|xargs seq|parallel -N 0 echo "2^2^20" '|' bc
    kostis · 2018-12-06 05:36:55 0
  • small CPU benchmark with PI, bc and time.

    Broken in two parts, first get the number of cores with cat /proc/cpuinfo |grep proc|wc -l and create a integer sequence with that number (xargs seq), then have GNU parallel loop that many times over the given command. Cheers! Show Sample Output


    -2
    time cat /proc/cpuinfo |grep proc|wc -l|xargs seq|parallel -N 0 echo "scale=4000\; a\(1\)\*4" '|' bc -l
    kostis · 2018-12-06 05:15:24 2

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list files recursively by size

save stderr only to a file
taken from http://www.unix.com/shell-programming-scripting/158311-how-tee-stderr.html " What does it mean? The redirection operator n>&m makes file descriptor n to be a copy of file descriptor m. So, whe are: - Opening a new file descriptor, 3, that is a copy of file descriptor 1, the standard output; - Making file descriptor 1 a copy of file descriptor 2, the standard error output; - Making file descriptor 2 to be a copy of file descriptor 3 (the "backup" of the standard output) in a short: we swapped the standard output and the standard error output. "

Backup entire system through SSH

Easily decode unix-time (funtion)

Find artist and title of a music cd, UPC code given (first result only)
I like curl better than wget, I just think that curl -s is a lot simpler than wget ... see I forget what you even have to do to get wget to pipe it's output Anyway, all in one sed command as "requested"

Reinstall a Synology NAS without loosing any data from commandline.
Seen many questions how-to reinstall synology nas dsm without loosing data, here you go. Wait for a few min and then head over to http://nasip and setup your fresh installed nas.

Get movie length

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Get top N files in X directory
You can simply run "largest", and list the top 10 files/directories in ./, or you can pass two parameters, the first being the directory, the 2nd being the limit of files to display. Best off putting this in your bashrc or bash_profile file

Notepad in a browser (type this in the URL bar)
It doesn't save your notes, but it's great for jotting something down quickly.

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