When `gnuplot` is run, it looks for an initialization file to load. This file is called `.gnuplot` on Unix and AmigaOS systems, and `GNUPLOT.INI` on other systems. If this file is not found in the current directory, the program will look for it in the HOME directory (under AmigaOS, MS-DOS, Windows and OS/2, the environment variable `GNUPLOT` should contain the name of this directory; on Windows NT, it will use `USERPROFILE` if GNUPLOT isn't defined). Note: if NOCWDRC is defined during the installation, `gnuplot` will not read from the current directory.
If the initialization file is found, `gnuplot` executes the commands in it. These may be any legal `gnuplot` commands, but typically they are limited to setting the terminal and defining frequently-used functions or variables.