Commands by sucotronic

Commands by sucotronic (10)

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Capture video Macbook webcam with cpu accelerated

Captures video from webcam and encodes it using the accelerated hardware provided by videotoolbox framework. It takes about 20% cpu in a i5 2015 macbook air. Show Sample Output

ffmpeg -f avfoundation -framerate 30 -video_size 1280x720 -pix_fmt uyvy422 -i "0" -c:v h264_videotoolbox -profile:v high -b:v 3M -color_range 1 /tmp/out.mp4

sucotronic · 2018-01-08 10:28:42 22

Create test images

Useful to test programs and webpages. Show Sample Output
This is sample output - yours may be different.
```
1.jpg
2.jpg
...
100.jpg
```
3

for i in {1..100}; do convert -background lightblue -fill blue -size 100x100 -pointsize 24 -gravity center label:$i $i.jpg; done

sucotronic · 2014-07-25 09:32:23 47
Search files with js declarations inside

Useful to crawl where the javascript is declared, and extract it a common file. You can redirect it to a file to review item by item. Show Sample Output
This is sample output - yours may be different.
```
path1/one.php
two.php
path2/path3/five.php
```
2

grep -r "<script" | grep -v src | awk -F: '{print $1}' | uniq

sucotronic · 2014-07-23 06:24:31 13
Rename with regular expression and leading zeros

Given a bunch of files with "wrong" date naming, it renames them in a "good" format. Show Sample Output
This is sample output - yours may be different.
```
result_26_2_2014.json.txt renamed as 20140226.txt
result_26_3_2014.json.txt renamed as 20140326.txt
result_26_4_2014.json.txt renamed as 20140426.txt
result_26_5_2014.json.txt renamed as 20140526.txt
result_26_7_2013.json.txt renamed as 20130726.txt
result_26_8_2013.json.txt renamed as 20130826.txt
result_26_9_2013.json.txt renamed as 20130926.txt
```
0

rename 's/result_([0-9]+)_([0-9]+)_([0-9]+)\.json\.txt/sprintf("%d%02d%02d.txt",$3,$2,$1)/ge' result_*.txt

sucotronic · 2014-06-13 07:34:32 7
mean color of an image

You can get the mean value for the colours in an image. Then you can determine, in general, how dark or bright is the image and run some other actions based on that. I'll recommend to readjust the brightness of the images using +sigmoidal-contrast option of imagemagick convert command. Show Sample Output
This is sample output - yours may be different.
```
105
```
1

convert image.jpg -resize 1x1 txt: | tail -1 | awk '{gsub(/[,\)]/," "); print $3+$4+$5}'

sucotronic · 2013-12-11 09:13:00 11
open remote desktop connection without X

You can use it to connect to remote windows machine and start some scritps that need user login
This is sample output - yours may be different.
1

xvfb-run --server-num=1 rdesktop -u name -p pass -g 1024x768 192.168.0.1

sucotronic · 2013-09-19 08:53:00 8
send raw data (hex written)using UDP to an IP and port

Use it to send raw data to a networked device. Used to interact with relay controller board whose documentation is lost, so use wireshark to sniff the sent data and replayed using the command.
This is sample output - yours may be different.
1

echo -n 023135 | perl -pe 's/([0-9a-f]{2})/chr hex $1/gie' | nc -4u -q1 -p5001 192.168.0.100 2000

sucotronic · 2013-09-18 14:31:47 8
Random Number Between 1 And 256

It takes a byte from /dev/random whose source is the kernel entropy pool (better source than other solutions). Show Sample Output
This is sample output - yours may be different.
```
 189
```
6

od -An -N1 -tu1 /dev/random

sucotronic · 2013-09-10 08:57:16 124
purge half of files in backup directory

If you have a directory with lot of backups (full backups I mean), when it gets to some size, you could want to empty some space. With this command you'll remove half of the files. The command assumes that your backup files starts with YYYYMMDD or that they go some alphabetical order. Show Sample Output
This is sample output - yours may be different.
```
(nothing, it will remove half of the files)
```
-1

find . | sort | awk 'NR%2==0' | xargs rm $1

sucotronic · 2013-07-11 07:36:18 11
Count the number of pages of all PDFs in current directory and all subdirs, recursively
This is sample output - yours may be different.
2

find . -name "*.pdf" -exec pdftk {} dump_data output \; | grep NumberOfPages | awk '{s+=$2} END {print s}'

sucotronic · 2013-01-09 15:26:45 44

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Run the built in PHP-server in current folder

You must have PHP 5.4.0 or later to be able to run the built in server. This web server is designed for developmental purposes only, and should not be used in production. URI requests are served from the current working directory where PHP was started, unless the -t option is used to specify an explicit document root. If a URI request does not specify a file, then either index.php or index.html in the given directory are returned. If neither file exists, then a 404 response code is returned. If a PHP file is given on the command line when the web server is started it is treated as a "router" script. The script is run at the start of each HTTP request. If this script returns FALSE, then the requested resource is returned as-is. Otherwise the script's output is returned to the browser. Standard MIME types are returned for files with extensions: .css, .gif, .htm, .html, .jpe, .jpeg, .jpg, .js, .png, .svg, and .txt. The .htm and .svg extensions are recognized from PHP 5.4.4 onwards. More information here: http://php.net/manual/en/features.commandline.webserver.php

c_rehash replacement

When you don't have c_rehash handy. Really simple - if you have a .pem file that doesn't really contain a x509 cert (let's say, newreq.pem), it will create a link, simply called '.0', pointing to that file.

Find last modified files in a directory and its subdirectories

Goes through all files in the directory specified, uses `stat` to print out last modification time, then sorts numerically in reverse, then uses cut to remove the modified epoch timestamp and finally head to only output the last 10 modified files. Note that on a Mac `stat` won't work like this, you'll need to use either: $ find . -type f -print0 | xargs -0 stat -f '%m%t%Sm %12z %N' | sort -nr | cut -f2- | head or alternatively do a `brew install coreutils` and then replace `stat` with `gstat` in the original command.

Replicate a directory structure dropping the files

Rename files in batch

Protect directory from an overzealous rm -rf *

-R Recursively change attributes of directories and their contents. +i to set the immutable bit to prevent even root from erasing or changing the contents of a file.

Big (four-byte) $RANDOM

Sometimes, in a shell script, you need a random number bigger than the range of $RANDOM. This will print a random number made of four hex values extracted from /dev/urandom.

for newbies, how to get one line info about all /bin programs

Get simple description on each file from /bin dir, in list form, usefull for newbies.

Convert images (jpg, png, ...) into a PDF

Converts images (maybe from scans) into a PDF

Throttle download speed (at speed x )

Throttle download speed $aria2c --max-download-limit=100K file.metalink Throttle upload speed $aria2c --max-upload-limit=100K file.torrent

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