The default binding to execute a shell command and pump the output to a buffer is ESC !. jed will prompt for a command line and spawn a subprocess for its execution.
Strictly speaking, jed does not support interactive subprocesses.
However, jed includes S-Lang code that ``emulates'' such a
subprocess. It may invoked by typing shell at the M-x
minibuffer prompt. A window will be created with a buffer named
*shell* attached to it. Any text entered at the system dependent
shell prompt will be executed in a subprocess and the result stuffed back
in the shell buffer. Don't try to execute any commands which try to take
over the keyboard or the screen or something undesirable may happen.
Examples of types of stupid commands are spawning other editors, logging
in to remote systems, et cetera. Even chdir is stupid since its
effect is not permanent. That is,
> cd ..
> dir
will not do what might naively be expected. That is, the two commands above are not equivalent to the single command dir ...