Syntax
#include <io.h> int isatty(int handle);Description
isatty determines whether the given handle is associated with a character device (a keyboard, display, or printer or serial port).
Note: In earlier releases of C Set ++, isatty began with an underscore (_isatty). Because it is defined by the X/Open standard, the underscore has been removed. For compatibility, The Developer's Toolkit will map _isatty to isatty for you.
isatty returns a nonzero value if the device is a character device. Otherwise, the return value is 0.
This example opens the console and determines if it is a character device:
#include <io.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys\stat.h>
int main(void)
{
int fh,result;
if (-1 == (fh = open("CON", O_RDWR, (S_IREAD|S_IWRITE)))) {
perror("Error opening console\n");
return EXIT_FAILURE;
}
result = isatty(fh);
if (0 != result)
printf("CON is a character device.\n");
else
printf("CON is not a character device.\n");
close(fh);
return 0;
/****************************************************************************
The output should be:
CON is a character device.
****************************************************************************/
}
Related Information
none