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Archive for the ‘*nix-tools’ Category

ducks: How Do I Find The Largest Top 10 Files and Directories On a Linux / UNIX / BSD?

Posted by jpluimers on 2017/03/20

Explains how to find out top 10 files and directories under Unix / Linux using sort and du command in human-readable format.

Interesting, especially

alias 'ducks=du -cks * | sort -rn | head'

Source: How Do I Find The Largest Top 10 Files and Directories On a Linux / UNIX / BSD?

via: Joe C. Hecht and nixCraft.

–jeroen

Posted in *nix, *nix-tools, Apple, BSD, Linux, Mac, OS X, Power User | Leave a Comment »

sed: convert Google Drive urls to direct download ones

Posted by jpluimers on 2017/03/14

RegEx Fu

RegEx Fu

One of the things after moving most of my things from copy.com to Google Drive was the direct (public) download URLs that copy.com provides. DropBox has them as well, but Google Drive lacks them in the UI.

There is a URL format that does allow for direct download though:

While Google aims for Drive to be a competent Dropbox competitor, there’s one small but key feature that isn’t easy: sharing direct download links. Fortunately, you can create your own.

Source: Share Direct Links to Files in Google Drive and Skip the Web Viewer

You can do a similar replacement for Google Doc URLs: How to Create Direct Download Links for Files on Google Drive

The Google Drive conversion seems straightforward as they convert from either of

https://drive.google.com/file/d/FILE_ID/edit?usp=sharing
https://drive.google.com/file/d/FILE_ID/view
https://drive.google.com/open?id=FILE_ID

to

https://drive.google.com/uc?export=download&id=FILE_ID

There are tons of RegEx examples for doing the first conversion at Regex to modify Google Drive shared file URL – Stack Overflow, but

  1. they don’t cover the two conversions
  2. they use the non-greedy (.*?) capturing groups which are tricky, introduce question mark escaping issues in hash and many sed implementations fail to implement non-greedy

Since I’m a command-line person, I’ve opted for a sed conversion that wasn’t in the above list. I choose sed because it allows you to convert either a line or a complete file at one time.

There are a few indispensable resources to get my regex expressions right:

So here it goes, starting with fixing https://drive.google.com/open?id=FILE_ID as it’s the most simple replacement because the FILE_ID is at the end.

First of all, these code fragments below are part of bash functions as bash functions remove the quoting hell you have with bash aliases.

Where bash aliases have no parameters (i.e. the arguments are put after the end of the expansion), functions have parameters. So if you want to pass all function parameters to a command inside a function, you have to use “$@” to pass all parameters.

This fragment fixes https://drive.google.com/open?id=FILE_ID printing each fix on one line using the p for printing command in sed:

sed -n 's@https://drive.google.com/open?id=@https://drive.google.com/uc?export=download\&id=@p' "$@"

A few remarks:

The second fragment fixes https://drive.google.com/file/d/FILE_ID/edit?usp=sharing and https://drive.google.com/file/d/FILE_ID/view again printing each fix:

sed -n 's@https://drive.google.com/file/d/\([^.]*\)/.*@https://drive.google.com/uc?export=download\&id=\1@p' "$@"

Some more remarks:

  • The FILE_ID is obtained from a capturing group during the match using \([^.]*\) and using the value in the replace with \1 as reference.
  • There is backslash escaping of the parentheses because that’s the sed way.
  • I’ve used a non-greedy \(.*?\) capturing group (sed can’t do that) but \([^.]*\)/ which matches any non-slash inside the capturing group until the first slash outside that group.

The final part is combing both replacement into one sed command:

sed 's@https://drive.google.com/open?id=@https://drive.google.com/uc?export=download\&id=@;s@https://drive.google.com/file/d/\([^.]*\)/.*@https://drive.google.com/uc?export=download\&id=\1@' "$@"

Final remarks:

–jeroen

Posted in Software Development, Development, Power User, *nix, Scripting, bash, sed script, *nix-tools, bash, sed | Leave a Comment »

Sniffers, Packet Capture – PFSenseDocs – cool, as it uses tcpdump/Wireshark format!

Posted by jpluimers on 2017/03/13

I hadn’t done a lot with pfSense in the past, which I regret a bit since I discovered this really cool feature: Sniffers, Packet Capture – PFSenseDocs.

The coolness isn’t so much that you can capture packets, but that it’s compatible with tcpdump and Wireshark (which has become available natively for Mac like 2 years ago).

Which means that you can download captures and open them in Wireshark.

So it’s as easy as 1,2,3:

  1. Set-up the capture on your router https://a.b.c.d/diag_packet_capture.php and start it
  2. Stop the capture and download the file
  3. Open the file in Wireshark or convert it to text using tshark

–jeroen

Posted in *nix, *nix-tools, Internet, Monitoring, pfSense, Power User, Routers, tcpdump, Wireshark | Leave a Comment »

bash – how do I list the functions defined in my shell? – Stack Overflow

Posted by jpluimers on 2017/03/07

Nice: “you can get both aliases and functions with compgen -a -A function

It uses the compgen completion generator. Simply brilliant (:

Source: bash – how do I list the functions defined in my shell? – Stack Overflow

–jeroen

Posted in *nix, *nix-tools, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »

Generate Mozilla Security Recommended Web Server Configuration Files

Posted by jpluimers on 2017/03/06

In case you manually want to configure or have a web-server that’s not supported by certbot for letsencrypt (yet): Generate Mozilla Security Recommended Web Server Configuration Files.

At the time of writing, these were supported by the generator (* were not supported by certbot for letsencrypt yet):

–jeroen

via: Feature request: admin web interface over HTTPS · Issue #630 · pi-hole/pi-hole

Posted in *nix, *nix-tools, Apache2, Encryption, Let's Encrypt (letsencrypt/certbot), Power User, Security | Leave a Comment »

 
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