patch-2.4.8 linux/lib/vsprintf.c

• Lines: 427
• Date: Sun Aug 5 13:12:41 2001
• Orig file: v2.4.7/linux/lib/vsprintf.c
• Orig date: Fri Apr 13 20:26:07 2001

diff -u --recursive --new-file v2.4.7/linux/lib/vsprintf.c linux/lib/vsprintf.c
@@ -9,6 +9,11 @@
  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  */
 
+/* 
+ * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+ * - changed to provide snprintf and vsnprintf functions
+ */
+
 #include <stdarg.h>
 #include <linux/types.h>
 #include <linux/string.h>
@@ -121,14 +126,15 @@
 #define SPECIAL	32		/* 0x */
 #define LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */
 
-static char * number(char * str, long long num, int base, int size, int precision, int type)
+static char * number(char * buf, char * end, long long num, int base, int size, int precision, int type)
 {
 	char c,sign,tmp[66];
-	const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
+	const char *digits;
+	const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+	const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 	int i;
 
-	if (type & LARGE)
-		digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+	digits = (type & LARGE) ? large_digits : small_digits;
 	if (type & LEFT)
 		type &= ~ZEROPAD;
 	if (base < 2 || base > 36)
@@ -162,46 +168,73 @@
 	if (i > precision)
 		precision = i;
 	size -= precision;
-	if (!(type&(ZEROPAD+LEFT)))
-		while(size-->0)
-			*str++ = ' ';
-	if (sign)
-		*str++ = sign;
+	if (!(type&(ZEROPAD+LEFT))) {
+		while(size-->0) {
+			if (buf <= end)
+				*buf = ' ';
+			++buf;
+		}
+	}
+	if (sign) {
+		if (buf <= end)
+			*buf = sign;
+		++buf;
+	}
 	if (type & SPECIAL) {
-		if (base==8)
-			*str++ = '0';
-		else if (base==16) {
-			*str++ = '0';
-			*str++ = digits[33];
-		}
-	}
-	if (!(type & LEFT))
-		while (size-- > 0)
-			*str++ = c;
-	while (i < precision--)
-		*str++ = '0';
-	while (i-- > 0)
-		*str++ = tmp[i];
-	while (size-- > 0)
-		*str++ = ' ';
-	return str;
+		if (base==8) {
+			if (buf <= end)
+				*buf = '0';
+			++buf;
+		} else if (base==16) {
+			if (buf <= end)
+				*buf = '0';
+			++buf;
+			if (buf <= end)
+				*buf = digits[33];
+			++buf;
+		}
+	}
+	if (!(type & LEFT)) {
+		while (size-- > 0) {
+			if (buf <= end)
+				*buf = c;
+			++buf;
+		}
+	}
+	while (i < precision--) {
+		if (buf <= end)
+			*buf = '0';
+		++buf;
+	}
+	while (i-- > 0) {
+		if (buf <= end)
+			*buf = tmp[i];
+		++buf;
+	}
+	while (size-- > 0) {
+		if (buf <= end)
+			*buf = ' ';
+		++buf;
+	}
+	return buf;
 }
 
 /**
- * vsprintf - Format a string and place it in a buffer
- * @buf: The buffer to place the result into
- * @fmt: The format string to use
- * @args: Arguments for the format string
- *
- * Call this function if you are already dealing with a va_list.
- * You probably want sprintf instead.
+* vsnprintf - Format a string and place it in a buffer
+* @buf: The buffer to place the result into
+* @size: The size of the buffer, including the trailing null space
+* @fmt: The format string to use
+* @args: Arguments for the format string
+*
+* Call this function if you are already dealing with a va_list.
+* You probably want snprintf instead.
  */
-int vsprintf(char *buf, const char *fmt, va_list args)
+int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 {
 	int len;
 	unsigned long long num;
 	int i, base;
-	char * str;
+	char *str, *end, c;
 	const char *s;
 
 	int flags;		/* flags to number() */
@@ -210,16 +243,25 @@
 	int precision;		/* min. # of digits for integers; max
 				   number of chars for from string */
 	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
-	                        /* 'z' support added 23/7/1999 S.H.    */
+				/* 'z' support added 23/7/1999 S.H.    */
 				/* 'z' changed to 'Z' --davidm 1/25/99 */
 
-	
-	for (str=buf ; *fmt ; ++fmt) {
+	str = buf;
+	end = buf + size - 1;
+
+	if (end < buf - 1) {
+		end = ((void *) -1);
+		size = end - buf + 1;
+	}
+
+	for (; *fmt ; ++fmt) {
 		if (*fmt != '%') {
-			*str++ = *fmt;
+			if (str <= end)
+				*str = *fmt;
+			++str;
 			continue;
 		}
-			
+
 		/* process flags */
 		flags = 0;
 		repeat:
@@ -230,8 +272,8 @@
 				case ' ': flags |= SPACE; goto repeat;
 				case '#': flags |= SPECIAL; goto repeat;
 				case '0': flags |= ZEROPAD; goto repeat;
-				}
-		
+			}
+
 		/* get field width */
 		field_width = -1;
 		if (isdigit(*fmt))
@@ -272,83 +314,112 @@
 		base = 10;
 
 		switch (*fmt) {
-		case 'c':
-			if (!(flags & LEFT))
-				while (--field_width > 0)
-					*str++ = ' ';
-			*str++ = (unsigned char) va_arg(args, int);
-			while (--field_width > 0)
-				*str++ = ' ';
-			continue;
-
-		case 's':
-			s = va_arg(args, char *);
-			if (!s)
-				s = "<NULL>";
-
-			len = strnlen(s, precision);
-
-			if (!(flags & LEFT))
-				while (len < field_width--)
-					*str++ = ' ';
-			for (i = 0; i < len; ++i)
-				*str++ = *s++;
-			while (len < field_width--)
-				*str++ = ' ';
-			continue;
-
-		case 'p':
-			if (field_width == -1) {
-				field_width = 2*sizeof(void *);
-				flags |= ZEROPAD;
-			}
-			str = number(str,
-				(unsigned long) va_arg(args, void *), 16,
-				field_width, precision, flags);
-			continue;
-
+			case 'c':
+				if (!(flags & LEFT)) {
+					while (--field_width > 0) {
+						if (str <= end)
+							*str = ' ';
+						++str;
+					}
+				}
+				c = (unsigned char) va_arg(args, int);
+				if (str <= end)
+					*str = c;
+				++str;
+				while (--field_width > 0) {
+					if (str <= end)
+						*str = ' ';
+					++str;
+				}
+				continue;
 
-		case 'n':
-			if (qualifier == 'l') {
-				long * ip = va_arg(args, long *);
-				*ip = (str - buf);
-			} else if (qualifier == 'Z') {
-				size_t * ip = va_arg(args, size_t *);
-				*ip = (str - buf);
-			} else {
-				int * ip = va_arg(args, int *);
-				*ip = (str - buf);
-			}
-			continue;
+			case 's':
+				s = va_arg(args, char *);
+				if (!s)
+					s = "<NULL>";
+
+				len = strnlen(s, precision);
+
+				if (!(flags & LEFT)) {
+					while (len < field_width--) {
+						if (str <= end)
+							*str = ' ';
+						++str;
+					}
+				}
+				for (i = 0; i < len; ++i) {
+					if (str <= end)
+						*str = *s;
+					++str; ++s;
+				}
+				while (len < field_width--) {
+					if (str <= end)
+						*str = ' ';
+					++str;
+				}
+				continue;
 
-		case '%':
-			*str++ = '%';
-			continue;
+			case 'p':
+				if (field_width == -1) {
+					field_width = 2*sizeof(void *);
+					flags |= ZEROPAD;
+				}
+				str = number(str, end,
+						(unsigned long) va_arg(args, void *),
+						16, field_width, precision, flags);
+				continue;
+
+
+			case 'n':
+				/* FIXME:
+				* What does C99 say about the overflow case here? */
+				if (qualifier == 'l') {
+					long * ip = va_arg(args, long *);
+					*ip = (str - buf);
+				} else if (qualifier == 'Z') {
+					size_t * ip = va_arg(args, size_t *);
+					*ip = (str - buf);
+				} else {
+					int * ip = va_arg(args, int *);
+					*ip = (str - buf);
+				}
+				continue;
 
-		/* integer number formats - set up the flags and "break" */
-		case 'o':
-			base = 8;
-			break;
+			case '%':
+				if (str <= end)
+					*str = '%';
+				++str;
+				continue;
+
+				/* integer number formats - set up the flags and "break" */
+			case 'o':
+				base = 8;
+				break;
+
+			case 'X':
+				flags |= LARGE;
+			case 'x':
+				base = 16;
+				break;
 
-		case 'X':
-			flags |= LARGE;
-		case 'x':
-			base = 16;
-			break;
-
-		case 'd':
-		case 'i':
-			flags |= SIGN;
-		case 'u':
-			break;
-
-		default:
-			*str++ = '%';
-			if (*fmt)
-				*str++ = *fmt;
-			else
-				--fmt;
-			continue;
+			case 'd':
+			case 'i':
+				flags |= SIGN;
+			case 'u':
+				break;
+
+			default:
+				if (str <= end)
+					*str = '%';
+				++str;
+				if (*fmt) {
+					if (str <= end)
+						*str = *fmt;
+					++str;
+				} else {
+					--fmt;
+				}
+				continue;
 		}
 		if (qualifier == 'L')
 			num = va_arg(args, long long);
@@ -367,13 +438,54 @@
 			if (flags & SIGN)
 				num = (signed int) num;
 		}
-		str = number(str, num, base, field_width, precision, flags);
+		str = number(str, end, num, base,
+				field_width, precision, flags);
 	}
-	*str = '\0';
+	if (str <= end)
+		*str = '\0';
+	else if (size > 0)
+		/* don't write out a null byte if the buf size is zero */
+		*end = '\0';
+	/* the trailing null byte doesn't count towards the total
+	* ++str;
+	*/
 	return str-buf;
 }
 
 /**
+ * snprintf - Format a string and place it in a buffer
+ * @buf: The buffer to place the result into
+ * @size: The size of the buffer, including the trailing null space
+ * @fmt: The format string to use
+ * @...: Arguments for the format string
+ */
+int snprintf(char * buf, size_t size, const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	i=vsnprintf(buf,size,fmt,args);
+	va_end(args);
+	return i;
+}
+
+/**
+ * vsprintf - Format a string and place it in a buffer
+ * @buf: The buffer to place the result into
+ * @fmt: The format string to use
+ * @args: Arguments for the format string
+ *
+ * Call this function if you are already dealing with a va_list.
+ * You probably want sprintf instead.
+ */
+int vsprintf(char *buf, const char *fmt, va_list args)
+{
+	return vsnprintf(buf, 0xFFFFFFFFUL, fmt, args);
+}
+
+
+/**
  * sprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @fmt: The format string to use
@@ -389,3 +501,4 @@
 	va_end(args);
 	return i;
 }
+