Run:

    ngspice -b pz1.cir 

and the operating point file 'PEBJT1--OP.0.q1' is generated.

The .model in the included library 'pebjt1.lib' has an output rootfile
parameter which determines the PEBJT1-- prefix.  The mixed case in the name
of the generated OP file is retained. Without any rootfile or output statement
in the .model, the file created will be named 'OP.0.q1'.