The three times god-forsaken Ghostscript (I use the Debian package
gs-afpl) suite is shipped worldwide with the US
letter default paper size. So, when you use it (e.g. to convert PS to PDF), and if the source file does not specify a paper size, the output file will have a
letter size, instead of the more sane
You can specify
A4 size at runtime, with the
ps2pdf -sPAPERSIZE=a4 input.ps
However, if you want to always use
A4 as default, you can change the
gs_init.ps file (
locate gs_init.ps), and uncomment the following line (remove the leading '
% /DEFAULTPAPERSIZE (a4) def
Beware that in Debian you will have to change it to (because the name of the variable is different):
/DEFPAPERSIZE (a4) def
You will only need to edit the
gs_init.ps file (as
root), make the changes and save the file. Subsequent
gs uses (e.g.
ps2pdf), will default to
A4 page size.