vsprintf.c

/*
 *  linux/lib/vsprintf.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
/*
 * 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
 * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
 * - scnprintf and vscnprintf
 */

#include <stdarg.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>

#include <asm/page.h>		/* for PAGE_SIZE */
#include <asm/div64.h>

/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) ((x) | 0x20)

/**
 * simple_strtoul - convert a string to an unsigned long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
{
	unsigned long result = 0,value;

	if (!base) {
		base = 10;
		if (*cp == '0') {
			base = 8;
			cp++;
			if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
				cp++;
				base = 16;
			}
		}
	} else if (base == 16) {
		if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
			cp += 2;
	}
	while (isxdigit(*cp) &&
	       (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
		result = result*base + value;
		cp++;
	}
	if (endp)
		*endp = (char *)cp;
	return result;
}

EXPORT_SYMBOL(simple_strtoul);

/**
 * simple_strtol - convert a string to a signed long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
long simple_strtol(const char *cp,char **endp,unsigned int base)
{
	if(*cp=='-')
		return -simple_strtoul(cp+1,endp,base);
	return simple_strtoul(cp,endp,base);
}

EXPORT_SYMBOL(simple_strtol);

/**
 * simple_strtoull - convert a string to an unsigned long long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
{
	unsigned long long result = 0,value;

	if (!base) {
		base = 10;
		if (*cp == '0') {
			base = 8;
			cp++;
			if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
				cp++;
				base = 16;
			}
		}
	} else if (base == 16) {
		if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
			cp += 2;
	}
	while (isxdigit(*cp)
	 && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
		result = result*base + value;
		cp++;
	}
	if (endp)
		*endp = (char *)cp;
	return result;
}

EXPORT_SYMBOL(simple_strtoull);

/**
 * simple_strtoll - convert a string to a signed long long
 * @cp: The start of the string
 * @endp: A pointer to the end of the parsed string will be placed here
 * @base: The number base to use
 */
long long simple_strtoll(const char *cp,char **endp,unsigned int base)
{
	if(*cp=='-')
		return -simple_strtoull(cp+1,endp,base);
	return simple_strtoull(cp,endp,base);
}


/**
 * strict_strtoul - convert a string to an unsigned long strictly
 * @cp: The string to be converted
 * @base: The number base to use
 * @res: The converted result value
 *
 * strict_strtoul converts a string to an unsigned long only if the
 * string is really an unsigned long string, any string containing
 * any invalid char at the tail will be rejected and -EINVAL is returned,
 * only a newline char at the tail is acceptible because people generally
 * change a module parameter in the following way:
 *
 * 	echo 1024 > /sys/module/e1000/parameters/copybreak
 *
 * echo will append a newline to the tail.
 *
 * It returns 0 if conversion is successful and *res is set to the converted
 * value, otherwise it returns -EINVAL and *res is set to 0.
 *
 * simple_strtoul just ignores the successive invalid characters and
 * return the converted value of prefix part of the string.
 */
int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);

/**
 * strict_strtol - convert a string to a long strictly
 * @cp: The string to be converted
 * @base: The number base to use
 * @res: The converted result value
 *
 * strict_strtol is similiar to strict_strtoul, but it allows the first
 * character of a string is '-'.
 *
 * It returns 0 if conversion is successful and *res is set to the converted
 * value, otherwise it returns -EINVAL and *res is set to 0.
 */
int strict_strtol(const char *cp, unsigned int base, long *res);

/**
 * strict_strtoull - convert a string to an unsigned long long strictly
 * @cp: The string to be converted
 * @base: The number base to use
 * @res: The converted result value
 *
 * strict_strtoull converts a string to an unsigned long long only if the
 * string is really an unsigned long long string, any string containing
 * any invalid char at the tail will be rejected and -EINVAL is returned,
 * only a newline char at the tail is acceptible because people generally
 * change a module parameter in the following way:
 *
 * 	echo 1024 > /sys/module/e1000/parameters/copybreak
 *
 * echo will append a newline to the tail of the string.
 *
 * It returns 0 if conversion is successful and *res is set to the converted
 * value, otherwise it returns -EINVAL and *res is set to 0.
 *
 * simple_strtoull just ignores the successive invalid characters and
 * return the converted value of prefix part of the string.
 */
int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);

/**
 * strict_strtoll - convert a string to a long long strictly
 * @cp: The string to be converted
 * @base: The number base to use