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Archive for February, 2010

How to create two wired virtual serial ports on Linux?

February 19th, 2010 fvicente No comments

To create two bridged virtual serial ports use the following command:

socat -d -d pty,raw,echo=0 pty,raw,echo=0

The output will show you which are the virtual ports (or pseudo terminals) created, e.g.:

2010/02/19 16:16:33 socat[9662] N PTY is /dev/pts/3
2010/02/19 16:16:33 socat[9662] N PTY is /dev/pts/4
2010/02/19 16:16:33 socat[9662] N starting data transfer loop with FDs [3,3] and [5,5]

Note: if you are using Ubuntu and you do not have this command, try:

sudo apt-get install socat

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How to calculate the space used by files in Linux?

February 19th, 2010 fvicente No comments

Suppose that you want to calculate the space used by all the png files in current directory and all its subdirectories. From a terminal type:

find . -name '*.png' -exec du -ab {} \; | awk '{total+=$0}END{print total}'

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How do I compare two binary files on Linux?

February 19th, 2010 fvicente No comments

The easiest way I found is dumping the binaries into text files using hexdump and then comparing them with your favourite program (diff, Meld, etc.). E.g.:

hexdump -C a.bin >a.txt
hexdump -C b.bin >b.txt
diff a.txt b.txt

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How do I add VNC to Terminal Server Client in Ubuntu?

February 19th, 2010 fvicente No comments

From a terminal type:

sudo apt-get install xtightvncviewer

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Extracting FLV meta tags with Python

February 5th, 2010 fvicente No comments

I’ve stolen this code from http://code.activestate.com/recipes/457406/ which in turn was stolen / ported from http://inlet-media.de/flvtool2 , made some small fixes in bugs related to the date conversion function, object and array unmarshaling, file name hardcoded, etc… If you want to learn more about the FLV format and metatags read Acrobat’s Video File Format Specification Version 10
Read more…

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