Execute

Execute a CLI command

This function attempts to execute the string commandString as a Shell command and arguments. The string can contain any valid input that you could type directly in a Shell, including input and output redirection using < and >. Note that Execute() doesn't return until the command(s) in commandString have returned.

The input FileHandle will normally be zero, and in this case Execute() will perform whatever was requested in the commandString and then return. If the input FileHandle is non-zero then after the (possibly empty) commandString is performed, subsequent input is read from the specified input FileHandle until the end of that file is reached.

In most cases, the output FileHandle must be provided, and is used by the Shell commands as their output stream unless output redirection was specified. If the output FileHandle is set to zero then the current window, normally specified as *, is used. Note that programs running under the Workbench do not normally have a current window.

Execute() may also be used to create a new interactive Shell Process just like those created with the NewShell command. In order to do this, you would call Execute() with an empty commandString, and pass a FileHandle relating to a new window as the input FileHandle. The output FileHandle would be set to zero. The Shell will read commands from the new window and will use the same window for output. This new Shell window can only be terminated by using the EndCLI command.

Under V37, if an input FileHandle is passed, and it's either interactive or a NIL: FileHandle, the pr_ConsoleTask of the new Process will be set to that FileHandle's Process (the same applies to SystemTagList()).

For this command to work, the program Run must be present in C: in versions before V36 (except that in 1.3.2 and any later 1.3 versions, the system first checks the resident list for Run).

commandString

pointer to a null-terminated string

input

BCPL pointer to a FileHandle

output

BCPL pointer to a FileHandle

success

BOOLEAN indicating whether Execute was successful in finding and starting the specified program. Note this is NOT the return code of the command(s).

You should use SystemTagList() instead of Execute() on Kickstart 2.0 (V36) and beyond.

The Execute() function result only indicates if the Execute() function could complete its task. Any command being executed will pass its own success/failure indication to the shell environment in which it was launched. This information is not available to the Execute() function.

SystemTagList()