Metrologic Optimus R, Руководство по программированию

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Chapter 3 Terminal Specific Function Library 75
kbhit
Purpose To check if there is any key being pressed.
Syntax int kbhit (void);
Example for (;!kbhit();); /* wait till a key is pressed */
Description This routine checks if there is any character waiting in the keyboard buffer for
being read out.
Return If any key is pressed, it returns 1 to indicate a character is put in the buffer.
Otherwise, it returns 0 to indicate the buffer is empty.
See Also clr_kb, getchar
SetKeyClick
Purpose To set key click.
Syntax void SetKeyClick (int status);
int status; /* 0: disable key click, 1(~5): enable key click */
Example SetKeyClick (1); /* enable key click sound */
Description There are five different tones available. You can choose a tone from the System
Menu or through programming.
Moreover, the frequency and duration pair of the key click is held in the system
global variable KEY_CLICK, which can be used to generate the key click
sound. Example: on_beeper(KEY_CLICK);
Return None
See Also GetKeyClick
TriggerStatus
Purpose To check if the scan key has been pressed.
Syntax int TriggerStatus (void);
Example if (TriggerStatus())
printf ("Scan key is pressed");
Description
This routine is used to check if the scan key has been pressed or not.
Return If the scan key is pressed, it returns 1.
Otherwise, it returns 0.
See Also dis_alpha, en_alpha, get_alpha_enable_state, get_alpha_lock_state