NGSPICE(1) General Commands Manual NGSPICE(1)

ngspice - circuit simulator derived from SPICE3f5

ngspice [options] [file ...]

This man page is just a small overview. The primary documentation of ngspice is in the ngspice User's Manual, which is available as a pdf file.

Don't try to source the file ".spiceinit" upon startup. Normally ngspice tries to find the file in the current directory, and if it is not found then in the user's home directory.
Enable command completion. (defect)
The program is being run on a terminal with mfb name term.
Run in batch mode. ngspice will read the standard input or the specified input file and do the simulation. Note that if the standard input is not a terminal, ngspice will default to batch mode, unless the -i flag is given.
Run in server mode. This is like batch mode, except that a temporary rawfile is used and then written to the standard output, preceded by a line with a single "@", after the simulation is done. This mode is used by the ngspice daemon.
Run in interactive mode. This is useful if the standard input is not a terminal but interactive mode is desired. Command completion is not available unless the standard input is a terminal, however.
Use rawfile as the default file into which the results of the simulation are saved.
Use circuitfile as the default input deck.
Display a verbose help on the arguments available to the program.
Display a version number and copyright information of the program.
All logs generated during a batch run (-b) will be saved in outfile.
Allow a program (e.g., xcircuit) to act as a GUI frontend for ngspice through a pipe. Thus ngspice will assume that the pipe is a tty and allows one to run in interactive mode.

Further arguments are taken to be SPICE input decks, which are read and saved. (If batch mode is requested then they are run immediately.)

Format of the rawfile. 0 for binary, and 1 for ascii.
A file which is copied verbatim to stdout when ngspice starts in interactive mode.
In this directory the spinit file will be searched.

various undocumented ngspice centric environment variables :

Common environment variables :

The System's Initialisation File.
.spiceinit or $HOME/.spiceinit
The User's Initialisation File.

sconvert(1), ngnutmeg(1), mfb(3), writedata(3), and
ngspice User's Manual at

Please report bugs to the ngspice project via

spice3: Tom Quarles (
nutmeg: User interface: Wayne Christopher (
ngspice: various authors (see