|GNU Octave Manual Version 3|
by John W. Eaton, David Bateman, Søren Hauberg
Paperback (6"x9"), 568 pages
RRP £24.95 ($39.95)
14.1.2 Terminal Input
Octave has three functions that make it easy to prompt users for
menu functions are normally
used for managing an interactive dialog with a user, and the
keyboard function is normally used for doing simple debugging.
- Built-in Function: input (prompt)
- Built-in Function: input (prompt, "s")
- Print a prompt and wait for user input. For example,
input ("Pick a number, any number! ")
prints the prompt
Pick a number, any number!
and waits for the user to enter a value. The string entered by the user is evaluated as an expression, so it may be a literal constant, a variable name, or any other valid expression.
inputonly returns one value, regardless of the number of values produced by the evaluation of the expression.
If you are only interested in getting a literal string value, you can call
inputwith the character string
"s"as the second argument. This tells Octave to return the string entered by the user directly, without evaluating it first.
Because there may be output waiting to be displayed by the pager, it is a good idea to always call
fflush (stdout)before calling
input. This will ensure that all pending output is written to the screen before your prompt. See section 14 Input and Output.
- Function File: menu (title, opt1, ...)
- Print a title string followed by a series of options. Each option will
be printed along with a number. The return value is the number of the
option selected by the user. This function is useful for interactive
programs. There is no limit to the number of options that may be passed
in, but it may be confusing to present more than will fit easily on one
See also disp, printf, input
input, the normal command line history and editing functions
are available at the prompt.
Octave also has a function that makes it possible to get a single character from the keyboard without requiring the user to type a carriage return.
- Built-in Function: kbhit ()
- Read a single keystroke from the keyboard. If called with one
argument, don't wait for a keypress. For example,
x = kbhit ();
will set x to the next character typed at the keyboard as soon as it is typed.
x = kbhit (1);
identical to the above example, but don't wait for a keypress, returning the empty string if no key is available.
|ISBN 095461206X||GNU Octave Manual Version 3||See the print edition|