Another way of controlling output from a Channel is via the boolean (integer) Comment attribute, which controls whether comments are appended to describe the purpose of each value. Comment has the value 1 by default but, if set to zero, will suppress these comments. This is normally appropriate only if you wish to minimise the amount of output, for example:
astSet( channel, "Full=-1, Comment=0" ); nobj = astWrite( channel, skyframe );
might result in the following more compact output:
Begin SkyFrame Naxes = 2 Ax1 = Begin SkyAxis End SkyAxis Ax2 = Begin SkyAxis End SkyAxis IsA Frame System = "FK4-NO-E" Epoch = 1958 End SkyFrame
AST A Library for Handling World Coordinate Systems in Astronomy