Advanced Assembly Programming - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 178

Before returning, all the entered characters are converted to uppercase. GetCmdLine()
always returns an error code of noErr.
We can use this function to request the user to enter a string from the keyboard when run-
ning programs on a demo board with the D-Bug12 monitor. Usually, the program would output
a message so that the user knows when to enter the string. The following instruction sequence
will ask the user to enter a string from the keyboard:
printf equ $EE88

GetCmdLine equ $EE8A

cmdlinelen equ 100

CR equ $0D

LF equ $0A

…

prompt db “Please enter a string: “,CR,LF,0

…

inbuf ds.b 100

…

ldd #prompt ; output a prompt to remind the user to

jsr [printf,PCR] ; enter a string

ldd #cmdlinelen ; push the CmdLineLen

pshd ; “

ldd #inbuf

call [GetCmdLine,PCR] ; read a string from the keyboard

puld ; clean up the stack

char * far sscanhex(char *HexStr, unsigned int *BinNum);
Pointer address: $EE8E
The sscanhex() function is used to convert a hex string to a binary number. The hex string
pointed to by HexStr may contain any number of ASCII hex characters. However, the converted
value must be no greater than $FFFF. The string must be terminated by either a space or a
NULL character.
Suppose one has entered an ASCII string that represents a number, then the following
instruction sequence will convert it into a hex number (or binary number):
sscanhex equ $EE8E

…

HexStr ds.b 10 ; input buffer to hold a hex string

BinNum ds.b 2 ; to hold the converted number

…

ldd #BinNum

pshd

ldd #HexStr

call [sscanhex,PCR]

leas 2,sp ; deallocates space used by outgoing parameters

…
int isxdigit(int c);
Pointer address: $EE92
The isxdigit() function tests the character passed in c for membership in the character set
[0..9, a..f, A..F]. If the character c is in this set, the function returns a nonzero (true) value.