Against Boredom: February 2016

2016-02-25

Note to self #2

When validating an XML against an XSD, make sure to use the correct XSD.

No matching global declaration available for the validation root

2016-02-24

hupquote #2

Igen ez is igaz, de van egy masik oldala is. Az egesz agile tema valahol annak besimerese, hogy a szoftverfejlesztes ido es eroforrasigenye egy bizonyos meret folott nem tervezheto.

-- http://hup.hu/szavazasok/20160222/nem_agile_fejlesztunk_mert?comments_per_page=9999#comment-1962685

2016-02-19

So I'm working on a pretty old system, with a new GCC compiler installed. A boost based project I just received started babbling about /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.11' not found (required by ./XYZ).
Wtf?

Turned out, the libstdc++.so.6.0.10 contains symbols up to GLIBCXX_3.4.10, but GCC 4.8.1 only links to newer ones.
How to check: strings /usr/lib64/libstdc++.so.6 | grep GLIBCXX

Solution: I just downgraded to GCC 4.3.4 - so long, suckers!

bash: homemade timeout replacement

So I was young and reckless, and didn't know there is a command called timeout in coreutils. This is how I managed to do it:

#!/bin/sh
{
    ./time_consuming_binary -a param -a notherparam --pleaseblock
} &
CHILDPID=$!
# Kill it after 30 sec
sleep 30
kill -9 $CHILDPID 2>&1 /dev/null

How to check if it had to be killed or not? Measure the wall time of the execution :) I've used it in a Nagios service check, the thing it watched either returned under 5 sec or blocked indefinitely (thanks, NFS), hence the 30 secs.

2016-02-08

boost: Boost.FileSystem linking struggle

Struggling with boost? SSDDBS

If you already linked boost_filesystem and boost_system but still receive errors like boost/system/error_code.hpp:221: undefined reference to `boost::system::generic_category()', then you should add the following flags to your $(CPP) flags: -DBOOST_NO_CXX11_SCOPED_ENUMS -DBOOST_SYSTEM_NO_DEPRECATED

2016-02-05

Adventure Time Advice

Jake: You see this cup? This is literally my favorite cup.
* Jake throws the cup through the window *
Jake: Now it's gone forever. So it's not real and I don't care about it anymore.

Against Boredom