Commands by luxaeterna101 (2)

  • curl -sLkIv --stderr - https://t.co/2rQjHfptZ8 -s: silences the output when piped to a different command -L: follow every redirect -k: ignores certificate errors -I: just request the headers -v: be verbose --stderr - : redirect stderr to stdout https://t.co/2rQjHfptZ8: URL to check for redirects piped to grep -i location: -i: grep target text ignoring case location: : greps every string containing "location:" piped to awk {'print $3'} prints the third column in every string piped to sed '/^$/d' removes blank lines Show Sample Output


    1
    curl -sLkIv --stderr - http://example.org | grep -i location: | awk {'print $3'} | sed '/^$/d'
    luxaeterna101 · 2019-02-28 12:07:27 0
  • Formats nicely the Openvpn log file. Show Sample Output


    0
    column -ts , /etc/openvpn/openvpn-status.log
    luxaeterna101 · 2016-05-17 09:36:58 0

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands


Check These Out

Alert visually until any key is pressed
I learned a few things reading this command. But I did run into a few issues: 1. On systems that don't use GNU echo (e.g. macOS 10.14.5 Mojave), the e option may not be supported. In this case ANSI escape codes will echoed as text and the terminal will not flash, like this: \e[?5h\e[38;5;1m A L E R T Thu Jun 20 16:31:29 PDT 2019 2. Since the read command strips\ignores leading backslashes, if a user types the backslash character once in the loop, it will not break. Typing backslash twice in a loop will break as expected. 3. The foreground color is set to red (\e[38;5;1m) on every loop. This could be set once before we call while, and then reset once when the loop breaks. 4. Instead of resetting the foreground color when it breaks, the video mode is set back to normal (\e[?5l). This has the effect of leaving the terminal text red until it is manually reset. The alternative I'm proposing here addresses these issues. I tested it on macOS and Arch Linux.

Fetch the current human population of Earth

Print a row of characters across the terminal
shorter than alternative

list files recursively by size

Convert a single-page PDF to a hi-res PNG, at 300dpi
If you skip this part: $ -density 300x300 you'll get a very lo-res image.

Show UDID of iPhone
Display the serial of the iPhone (aka UDID).

Add temporary swap space
In addition to a swap partition, Linux can also use a swap file. Some programs, like g++, can use huge amounts of virtual memory, requiring the temporary creation of extra space.

Show top running processes by the number of open filehandles they have
I think I could cut down the number of pipes here, any suggestions?

Synchronise a file from a remote server
You will be prompted for a password unless you have your public keys set-up.

Print every Nth line
Sometimes commands give you too much feedback. Perhaps 1/100th might be enough. If so, every() is for you. $ my_verbose_command | every 100 will print every 100th line of output. Specifically, it will print lines 100, 200, 300, etc If you use a negative argument it will print the *first* of a block, $ my_verbose_command | every -100 It will print lines 1, 101, 201, 301, etc The function wraps up this useful sed snippet: $ ... | sed -n '0~100p' don't print anything by default $ sed -n starting at line 0, then every hundred lines ( ~100 ) print. $ '0~100p' There's also some bash magic to test if the number is negative: we want character 0, length 1, of variable N. $ ${N:0:1} If it *is* negative, strip off the first character ${N:1} is character 1 onwards (second actual character).


Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: