What tool would convert map coordinates ?

[Bernard <bdebreil@teaser.fr>]

Hi to Everyone,

I need to convert map coordinates from Lambert II + to decimal degrees. 
I found a tool which works online on a web site, but the results lack 
precision : it gives degrees, minutes and integer seconds (no decimal 
after the seconds, while one second is about 30 meters of distance). 
More accurate tools are available for MSWIN, but I wish to use Linux 
resources. I have installed the gdal package, which I have successfully 
used for other purposes, but I don't know whether or not this would fit 
my present purpose. I don't have access to the GDAL doc, since it is 
provided on a strange format (dox), that I don't know how to use.

Thanks in advance for your help