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Re: libpng on Linux [message #46694 is a reply to message #46691]

Wed, 13 July 2016 20:43

dolik.rce
Messages: 1789
Registered: August 2008
Location: Czech Republic

Ultimate Contributor

Hi Luigi,

forlano wrote on Wed, 13 July 2016 11:23

my programs use the plugins/png. This means, I believe, that does not matter if the user has installed his version of the png library on Linux.

It is only compiled statically on windows. Pretty much every linux system with graphic interface has libpng available, so there is no need to compile it statically. Also it is better in terms of security - distributions often update the libraries with security fixes.

forlano wrote on Wed, 13 July 2016 11:23

However one of my user reported that upgrading his distro my program stopped to work:

>> ./Vega7: error while loading shared libraries: libpng12.so.0: cannot
>> open shared object file: No such file or directory

My guess is, that the problem is not actually missing libpng, but rather wrong version of it. libpng12 is rather old (but many stable distros still use it). If you compiled on system with older version of libpng (where the library name is lipng12.so), it won't run on systems where only newer version (e.g. Arch Linux currently uses libpng16.so) is installed.

forlano wrote on Wed, 13 July 2016 11:23

Can I compile statically such package. Can I do something to prevent the problem?

The most common solution is to compile on the same distribution that the end-user uses. Sometimes it is not simple, but it actually prevents many troubles, not just mixed up libs. Alternatively, you could tweak the flags in plugin/png to make it use static compilation.

Best regards,
Honza

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