Question on measuring contours

[Filippidis Vangelis]

Dear Sirs,

I am a new GRASS user using GRASS 4.1.5 running on Linux (2.0.29). 
I have digitized all contour lines from 1:50000 topographic map,
and i want to caclulate the total length of them in Km. 
Can you help me ?

Thank you in advance

Filippidis Evangelos ( efilippi at for.auth.gr )
Phd Student
Dep. of Forestry and Natural Environment
Aristotelian University of Thessaloniki
Thessaloniki, Greece.