Page 427 - Programming Microcontrollers in C

412 Chapter 8 MCORE, A RISC Machine

{
put(‘\n’);
put(‘\r’);
}
else
put(x);
}

/* send a string to the serial port */
void puts(BYTE *a)
{
while(*a!=’\0')
putchar(*a++);
}

/* This function reads a string into the buffer a. The
length of the buffer is max. If the string is less than
max long, the function returns the number of characters
entered. If the string is longer than the buffer, the
buffer is filled and a -1 is returned. The input string
is terminated by either a ‘\n’ or a ‘\r’. */

int gets(BYTE *a,int max) /* no echo */
{
int i=0,c;

do /* read in data a byte at a time */
{
*a++=c=getch();
}while(c!=’\n’&&c!=’\r’&&++i<max-1);
*a=’\0'; /* make it a string */
return (i>=max)?-1:i;
}

/* same as gets() but data entered are echoed */
int getse(BYTE *a,int max) /* with echo */
{
int i=0,c;

do
{
*a++=c=getchar();
}while(c!=’\n’&&c!=’\r’&&++i<max-1);
*a=’\0';
return (i>=max)?-1:i;
}
Listing 8-8: General Serial Input/Output Functions