<Libc> Add support for scanf to accept formatted

src/lib/libc/include/stdio.h

@@ -30,6 +30,7 @@ extern FILE stddev[];
 
 int __printf(const char *fmt, ...);
 int __eprintf(const char *fmt, ...);
+int scanf(const char *fmt, ...);
 int fputs(const FILE *, const char *);
 int fputc(const FILE *, const char);
 int fgetc(const FILE *, char *);
@@ -39,6 +40,7 @@ char getchar();
 #ifdef _STDBOOL_H_
 int fprintf(const FILE *, bool, const char *fmt, ...);
 #ifdef _STDARG_H_
+int vscanf(const FILE *, const char *fmt, va_list args);
 int vprintf(const FILE *, bool, const char *fmt, va_list args);
 #endif
 #endif

src/lib/libc/printf.c

@@ -109,8 +109,10 @@ static int fltprint(const FILE *dev, bool en_stdout, double flt,
 	{
 		frac *= 10.0;
 		padf--;
+		d = (long) frac;
+		if (!d)
+			__fputc(dev, en_stdout, '0');
 	}
-	d = (long) frac;
 	ret += unumprint(dev, en_stdout, d,10, '0', 0);
 
 	return ret;

src/lib/libc/scanf.c

@@ -15,6 +15,8 @@
 #include <ccpfs.h>
 #include <stdio.h>
 #include <stddev.h>
+#include <stdarg.h>
+#include <ctype.h>
 
 int fgetc(const FILE *dev, char *c)
 {
@@ -42,3 +44,201 @@ char getchar()
     } while(temp != '\r');
     return c;
 }
+
+int vscanf(const FILE *dev, const char *fmt, va_list args)
+{
+	int ret = 0;
+	int l_ret;
+	int N;
+	char c;
+	while (*fmt != '\0')
+	{
+		l_ret = 0;
+		if (*fmt == '%')
+		{
+			fmt++;
+loop:
+			switch (*fmt)
+			{
+				case 'i':
+				case 'd':
+				{
+					int a = 0;
+					N = 0;
+					// skip leading whitespaces
+					do
+					{
+						fgetc(dev, &c);
+						if (c == '\r')
+							fputc(stdout, '\n');
+						else
+							fputc(stdout, c);
+					} while (isSpace(c));
+					// initialize first int digit
+					if (c == '-')
+						N = 1;
+					else if (isDigit(c))
+						a = c - '0';
+					// append rest of digits till whitespace
+					do
+					{
+						fgetc(dev, &c);
+						if (isDigit(c))
+						{
+							a *= 10;
+							a += (c - '0');
+							fputc(stdout, c);
+						}
+						else if (a && (c == 0x7f || c== 0x08))
+						{
+							a /= 10;
+							fputs(stdout, "\b \b");
+						}
+					} while (!isSpace(c));
+					(c == '\r') ? fputc(stdout, '\n') : fputc(stdout, c);
+					if (l_ret >= 2)
+						*(int64_t *)va_arg(args, int64_t *) = (N) ? -(a) : a;
+					else if (l_ret == 1)
+						*(long *)va_arg(args, long *) = (N) ? -(a) : a;
+					else
+						*(int *)va_arg(args, int *) = (N) ? -(a) : a;
+					ret++;
+					break;
+				}
+				case 'l':
+				{
+					l_ret++;
+					fmt++;
+					goto loop;
+				}
+#if USE_FLOAT == 1
+				case 'f':
+				{
+					float a = 0;
+					unsigned int rp = 0; // radix point
+					float e = 1;
+					unsigned int fl = 1; // floating length - length after radix point
+					N = 0;
+					// skip leading whitespaces
+					do
+					{
+						fgetc(dev, &c);
+						if (c == '\r')
+							fputc(stdout, '\n');
+						else
+							fputc(stdout, c);
+					} while (isSpace(c));
+					if (c == '.')
+						rp = 1;
+					else if (c == '-')
+						N = 1;
+					else if (isDigit(c))
+						a = (float)(c - '0');
+					// append rest of digits till whitespace
+					do
+					{
+						fgetc(dev, &c);
+						if (!rp && c == '.')
+						{
+							rp = 1;
+							fputc(stdout, c);
+						}
+						else if (isDigit(c))
+						{
+							if (rp)
+							{
+								e /= 10.0;
+								a += (e * (float)(c - '0'));
+								fl *= 10;
+							}
+							else
+							{
+								a *= 10.0;
+								a += (float)(c - '0');
+							}
+							fputc(stdout, c);
+						}
+						else if (a && (c == 0x7f || c == 0x08))
+						{
+							long d = (long)a;
+							float frac = a - (float)d;
+							if (frac == 0.0 && rp)
+								rp = 0;
+							else if (rp)
+							{
+								fl /= 10;
+								frac *= fl;
+								frac = (long)frac / (float)fl;
+								a = d + frac;
+							}
+							else
+								a = (int)a / 10;
+							fputs(stdout, "\b \b");
+						}
+					} while (!isSpace(c));
+					(c == '\r') ? fputc(stdout, '\n') : fputc(stdout, c);
+					*(float *)va_arg(args, float *) = (N) ? -(a) : a;
+					ret++;
+					break;
+				}
+#endif
+				case 'c':
+				{
+					*(char *)va_arg(args, char *) = getchar();
+					ret++;
+					break;
+				}
+				case 's':
+				{
+					int i = 0;
+					char *s = va_arg(args, char *);
+					//skip leading whitespaces
+					do
+					{
+						fgetc(dev, &c);
+						if (c == '\r')
+							fputc(stdout, '\n');
+						else
+							fputc(stdout, c);
+					} while (isSpace(c));
+					s[i++] = c;
+					do
+					{
+						fgetc(dev, &c);
+						if (isSpace(c))
+							break;
+						else if (i && (c == 0x7f || c == 0x08))
+						{
+							i--;
+							fputs(stdout, "\b \b");
+						}
+						else
+							s[i++] = c;
+						fputc(stdout, c);
+					} while (!isSpace(c));
+					(c == '\r') ? fputc(stdout, '\n') : fputc(stdout, c);
+					s[i] = '\0';
+					ret++;
+					break;
+				}
+				default:
+					return -1;
+			}
+			continue;
+		}
+		/* increment pointer if % not found */
+		fmt++;
+	}
+	fputc(stdout, '\n');
+	return ret;
+}
+
+int scanf(const char *fmt, ...)
+{
+	int ret;
+	va_list va;
+	va_start(va, fmt);
+	ret = vscanf(stdin, fmt, va);
+	va_end(va);
+	return ret;
+}