2.22 shell

The shell command spawns an interactive shell. To return to `gnuplot`, type `logout` if using VMS, exit or the END-OF-FILE character if using Unix, `endcli` if using AmigaOS, or exit if using MS-DOS or OS/2.

There are two ways of spawning a shell command: using system command or via `!` ($ if using VMS). The former command takes a string as a parameter and thus it can be used anywhere among other gnuplot commands, while the latter syntax requires to be the only command on the line. Control will return immediately to `gnuplot` after this command is executed. For example, in AmigaOS, MS-DOS or OS/2,

      ! dir

or

      system "dir"

prints a directory listing and then returns to `gnuplot`.

Other examples of the former syntax:

       system "date"; set time; plot "a.dat"
       print=1; if (print) replot; set out; system "lpr x.ps"

On an Atari, the `!` command first checks whether a shell is already loaded and uses it, if available. This is practical if `gnuplot` is run from `gulam`, for example.