PEDIT loads the procedure buffer into a temporary file in your current directory, then runs a process which allows you to edit it with the default editor (usually vi). If you exit the editor and save changes, the modified procedure is loaded back into the procedure buffer, but not executed. If quit the editor without saving changes, the procedure buffer is left unchanged.
On a UNIX system, you can use another editor by defining the environment variable VISUAL. For example, to use the vi editor, jus execute the following BEFORE running VISTA:
setenv VISUAL viA maximum number of 2500 lines is allowed in a procedure. If you leave the editor with EXIT and your procedure contains more than 2500 lines, it is truncated and the last line is set to 'END'. Also, each line is allowed a maximum length of 80 characters. You can have longer lines by using linecontinue.html as described earlier.
You may also define procedures (with a maximum length of 2500 lines) with the editor before running VISTA, and read them into the procedure buffer with RP or execute them with CALL.