or partial paths from environmental variables. The env variable
names have to start with '$' as the first character after the .inc
or .lib token. Two consecutive env variables are possible. They are
read each until directory separator '/' or '\\', or if none is found,
until the end of the line. In this case the filename has to be included
in the env variable. A .lib line may look like
.lib "$ENVS1\$ENVS2/libraries\sky130_fd_pr\latest\models\sky130.lib.spice" tt
If an env variable is read successfully, a ngspice variable with
the same name (without leading '$') and contents is defined for
use in a .control section.
Holger Vogt
ace47103e7