--- /dev/null
+/*
+ * _scanf.c
+ *
+ * (C) Copyright 2001 Ullrich von Bassewitz (uz@cc65.org)
+ *
+ * This is the basic layer for all scanf type functions.
+ */
+
+
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <setjmp.h>
+#include <ctype.h>
+#include <limits.h>
+
+#include "_scanf.h"
+
+
+
+/*****************************************************************************/
+/* SetJmp return codes */
+/*****************************************************************************/
+
+
+
+#define RC_OK 0 /* Regular call */
+#define RC_EOF 1 /* EOF reached */
+#define RC_NOCONV 2 /* No conversion possible */
+
+
+
+/*****************************************************************************/
+/* Data */
+/*****************************************************************************/
+
+
+
+static jmp_buf JumpBuf; /* Label that is used in case of EOF */
+static char C; /* Character from input */
+static unsigned Width; /* Maximum field width */
+
+
+
+/*****************************************************************************/
+/* Character sets */
+/*****************************************************************************/
+
+
+
+/*****************************************************************************/
+/* Code */
+/*****************************************************************************/
+
+
+
+static void ReadChar (struct indesc* d)
+/* Get an input character, count characters */
+{
+ C = d->fin (d);
+ ++d->ccount;
+}
+
+
+
+static void SkipWhite (struct indesc* d)
+/* Skip white space in the input and return the first non white character */
+{
+ while (isspace (C)) {
+ ReadChar (d);
+ }
+}
+
+
+
+static unsigned char ReadSign (struct indesc* d)
+/* Read an optional sign and skip it. Return 1 if the value is positive,
+ * return 0 otherwise.
+ */
+{
+ switch (C) {
+ case '-':
+ ReadChar (d);
+ return 0;
+ case '+':
+ ReadChar (d);
+ /* FALLTHROUGH */
+ default:
+ return 1;
+ }
+}
+
+
+
+static unsigned char HexVal (char C)
+/* Convert a digit to a value */
+{
+
+ if (isdigit (C)) {
+ return C - '0';
+ } else {
+ return C - toupper (C) + ('A' + 10);
+ }
+}
+
+
+
+static unsigned long ReadInt (struct indesc* d, unsigned char Base)
+/* Read an integer */
+{
+ unsigned long V = 0;
+
+ /* Value must start with a digit */
+ if (!isdigit (C)) {
+ longjmp (JumpBuf, RC_NOCONV);
+ }
+
+ /* Read the value */
+ while (isxdigit (C) && Width-- > 0) {
+ printf ("ReadInt: '%c'\n", C);
+ V = V * Base + HexVal (C);
+ ReadChar (d);
+ }
+
+ /* Return the read value */
+ return V;
+}
+
+
+
+int _scanf (struct indesc* d, const char* format, va_list ap)
+/* This is the routine used to do the actual work. It is called from several
+ * types of wrappers to implement the actual ISO xxscanf functions.
+ */
+{
+ unsigned Conversions; /* Number of conversions */
+
+ char F; /* Character from format string */
+ unsigned char NoAssign; /* Supppress assigment */
+ unsigned char IsShort; /* Short type */
+ unsigned char IsLong; /* Long type */
+ unsigned char Positive; /* Flag for positive value */
+ unsigned char Result; /* setjmp result */
+
+ /* Variables that hold intermediate values */
+ void* P;
+ long L;
+
+
+ /* Initialize variables */
+ Conversions = 0;
+ d->ccount = 0;
+
+ /* Set up the jump label. The get() routine will use this label when EOF
+ * is reached.
+ */
+ Result = setjmp (JumpBuf);
+ printf ("Result = %u\n", Result);
+ if (Result == RC_OK) {
+
+Again:
+ /* Get the next input character */
+ ReadChar (d);
+
+ /* Walk over the format string */
+ while (F = *format++) {
+
+ /* Check for a conversion */
+ if (F != '%' || *format == '%') {
+
+ /* %% or any char other than % */
+ if (F == '%') {
+ ++format;
+ }
+
+ /* Check for a match */
+ if (isspace (F)) {
+
+ /* Special white space handling: Any whitespace matches
+ * any amount of whitespace including none(!). So this
+ * match will never fail.
+ */
+ SkipWhite (d);
+ continue;
+
+ } else if (F != C) {
+
+ /* A mismatch. We will stop scanning the input and return
+ * the number of conversions.
+ */
+ printf ("F = '%c', C = '%c' --> mismatch\n", F, C);
+ return Conversions;
+
+ } else {
+
+ /* A match. Read the next input character and start over */
+ goto Again;
+
+ }
+
+ } else {
+
+ /* A conversion. Skip the percent sign. */
+ F = *format++;
+
+ /* Initialize variables */
+ NoAssign = 0;
+ IsShort = 0;
+ IsLong = 0;
+ Width = UINT_MAX;
+
+ /* Check for flags. */
+ while (1) {
+ if (isdigit (F)) {
+ Width = 0;
+ do {
+ /* ### Non portable ### */
+ Width = Width * 10 + (F & 0x0F);
+ F = *format++;
+ } while (isdigit (F));
+ } else {
+ switch (F) {
+ case '*': NoAssign = 1; break;
+ case 'h': IsShort = 1; break;
+ case 'l':
+ case 'L': IsLong = 1; break;
+ default: goto FlagsDone;
+ }
+ F = *format++;
+ }
+ }
+FlagsDone:
+
+ /* Check for the actual conversion character */
+ printf ("F = '%c'\n", F);
+ switch (F) {
+
+ case 'D':
+ IsLong = 1;
+ case 'd':
+ /* Optionally signed decimal integer */
+ SkipWhite (d);
+ Positive = ReadSign (d);
+ L = ReadInt (d, 10);
+ if (!Positive) {
+ L = -L;
+ }
+ if (!NoAssign) {
+ /* All pointers have the same size, so save some
+ * code here.
+ */
+ P = va_arg (ap, void*);
+ if (IsLong) {
+ *(long*)P = L;
+ } else {
+ *(int*)P = (int) L;
+ }
+ }
+ break;
+
+ case 'i':
+ /* Optionally signed integer with a base */
+ break;
+
+ case 'o':
+ /* Unsigned octal integer */
+ L = ReadInt (d, 8);
+ if (!NoAssign) {
+ /* All pointers have the same size, so save some
+ * code here.
+ */
+ P = va_arg (ap, void*);
+ if (IsLong) {
+ *(long*)P = L;
+ } else {
+ *(int*)P = (int) L;
+ }
+ }
+ break;
+
+ case 'u':
+ /* Unsigned decimal integer */
+ L = ReadInt (d, 10);
+ if (!NoAssign) {
+ /* All pointers have the same size, so save some
+ * code here.
+ */
+ P = va_arg (ap, void*);
+ if (IsLong) {
+ *(long*)P = L;
+ } else {
+ *(int*)P = (int) L;
+ }
+ }
+ break;
+
+ case 'x':
+ case 'X':
+ /* Unsigned hexadecimal integer */
+ L = ReadInt (d, 16);
+ if (!NoAssign) {
+ /* All pointers have the same size, so save some
+ * code here.
+ */
+ P = va_arg (ap, void*);
+ if (IsLong) {
+ *(long*)P = L;
+ } else {
+ *(int*)P = (int) L;
+ }
+ }
+ break;
+
+ case 'E':
+ case 'e':
+ case 'f':
+ case 'g':
+ /* Optionally signed float */
+ break;
+
+ case 's':
+ /* Whitespace terminated string */
+ break;
+
+ case 'c':
+ /* Fixed length string */
+ break;
+
+ case '[':
+ /* String using characters from a set */
+ break;
+
+ case 'p':
+ /* Pointer */
+ break;
+
+ case 'n':
+ /* Store characters consumed so far */
+ break;
+
+ default:
+ /* Invalid conversion */
+ break;
+
+ }
+
+ /* Skip the format char */
+ goto Again;
+
+ }
+
+ }
+
+ } else if (Result == RC_EOF) {
+
+ /* Jump via JumpBuf means EOF on input */
+ if (d->ccount == 0) {
+ /* Special case: error */
+ return -1;
+ }
+
+ }
+
+ /* Return the number of conversions */
+ return Conversions;
+}
+
+
+
projects / cc65 / commitdiff