string.c File Reference

#include "string.h"
#include <stdarg.h>
#include <stddef.h>

Functions
size_t	strlen (const char *str)
	Determine the length of a string.
size_t	strnlen (const char *str, size_t max_len)
	Determine the length of a fixed-size string.
char *	strrev (char *str)
	Reverses string.
char *	strcpy (char *dest, const char *src)
	Copies string.
char *	strncpy (char *dest, const char *src, size_t n)
	Copies string with maximum length.
int	strncmp (const char *str1, const char *str2, size_t n)
	Compares two strings with maximum length.
int	strcmp (const char *str1, const char *str2)
	Compares two strings.
char	tolower (char c)
	Converts ASCII letter to lowercase.
int	istrncmp (const char *str1, const char *str2, size_t n)
size_t	strnlen_terminator (const char *str, size_t max, char terminator)
	Calculates string length with custom terminator.
char *	itoa (long num, char *str, int base)
	Converts signed number to string.
char *	uitoa (unsigned long num, char *str, int base)
	Converts unsigned number to string.
char *	vsprintf (char *buf, const char *fmt, va_list args)
	Kernel vsprintf params: %% c s p l(mod) d i x.
char *	sprintf (char *buf, const char *fmt,...)
	Kernel sprintf params: %% c s p l(mod) d i x.
int	is_digit (char c)
	Determines if given char is an ASCII digit.
int	to_numeric_digit (char c)
	Converts ASCII digit to numeric.
void *	memset (void *ptr, int c, size_t size)
	Sets first bytes of memory pointed to specified value.
void *	memcpy (void *dstptr, const void *srcptr, size_t size)
	Copies memory from one place to another.
int	memcmp (void *ptr1, void *ptr2, size_t len)
	Compares the first num bytes of the block of memory pointed by ptr1 to the first num bytes pointed by ptr2.

Function Documentation

is_digit()

int is_digit

(

char

c

)

Determines if given char is an ASCII digit.

Parameters

c	Character to test

Returns

int 1 if given char is digit

istrncmp()

int istrncmp	(	const char *	str1,
		const char *	str2,
		size_t	n )

References tolower().

itoa()

char * itoa	(	long	num,
		char *	str,
		int	base )

Converts signed number to string.

Parameters

num	Long to convert
str	Buffer
base	Base to use when converting the number

Returns

char* Buffer

References base, and strrev().

memcmp()

int memcmp	(	void *	ptr1,
		void *	ptr2,
		size_t	len )

Compares the first num bytes of the block of memory pointed by ptr1 to the first num bytes pointed by ptr2.

Parameters

ptr1	Pointer to block of memory
ptr2	Pointer to block of memory
len	Number of bytes to compare

Returns

int

• 0 if matches,
• -1 the first byte that does not match in both memory blocks has a lower value in ptr1 than in ptr2,
• 1 the first byte that does not match in both memory blocks has a greater value in ptr1 than in ptr2

memcpy()

void * memcpy	(	void *	dstptr,
		const void *	srcptr,
		size_t	size )

Copies memory from one place to another.

Parameters

dstptr	Destination pointer
srcptr	Source pointer
size	Length of copied memory

Returns

void* Destination pointer

References size.

memset()

void * memset	(	void *	ptr,
		int	c,
		size_t	size )

Sets first bytes of memory pointed to specified value.

Parameters

ptr	Pointer to the block of memory to fill
c	Value to be set
size	Number of bytes to set

Returns

void* Pointer to the block of memory

References size.

sprintf()

char * sprintf	(	char *	buf,
		const char *	fmt,
			... )

Kernel sprintf params: %% c s p l(mod) d i x.

Parameters

buf	Buffer
fmt	Text to format
...	Args

Returns

char* Buffer

References vsprintf().

strcmp()

int strcmp	(	const char *	str1,
		const char *	str2 )

Compares two strings.

Parameters

str1	String
str2	String

Returns

int 0 -> str1==str2, <0 -> str1<str2, >0 ->str1>str2

References strlen(), and strncmp().

strcpy()

char * strcpy	(	char *	dest,
		const char *	src )

Copies string.

Parameters

dest	Destination buffer
src	Input buffer

Returns

char* Pointer to destination buffer

strlen()

size_t strlen

(

const char *

str

)

Determine the length of a string.

Parameters

str

String

Returns

size_t Length

strncmp()

int strncmp	(	const char *	str1,
		const char *	str2,
		size_t	n )

Compares two strings with maximum length.

Parameters

str1	String
str2	String
n	Max length

Returns

int 0 -> str1==str2, <0 -> str1<str2, >0 ->str1>str2

strncpy()

char * strncpy	(	char *	dest,
		const char *	src,
		size_t	n )

Copies string with maximum length.

Parameters

dest	Destination buffer
src	Input buffer
n	Max length

Returns

char* Pointer to destination buffer

strnlen()

size_t strnlen	(	const char *	str,
		size_t	max_len )

Determine the length of a fixed-size string.

Parameters

str
max_len

Returns

size_t

strnlen_terminator()

size_t strnlen_terminator	(	const char *	str,
		size_t	max,
		char	terminator )

Calculates string length with custom terminator.

Parameters

str	String to measure length
max	Max length of string
terminator	Custom terminator

Returns

int Length

strrev()

char * strrev

(

char *

str

)

Reverses string.

Parameters

str	String to reverse

Returns

char* str

References strlen().

to_numeric_digit()

int to_numeric_digit

(

char

c

)

Converts ASCII digit to numeric.

Parameters

c	ASCII digit

Returns

int Numeric digit

tolower()

char tolower

(

char

c

)

Converts ASCII letter to lowercase.

Parameters

c	Input letter

Returns

char Lowercase letter

uitoa()

char * uitoa	(	unsigned long	num,
		char *	str,
		int	base )

Converts unsigned number to string.

Parameters

num	Unsigned Long to convert
str	Buffer
base	Base to use when converting the number

Returns

char* Buffer

References base, and strrev().

vsprintf()

char * vsprintf	(	char *	buf,
		const char *	fmt,
		va_list	args )

Kernel vsprintf params: %% c s p l(mod) d i x.

Parameters

buf	Buffer
fmt	Text to format
va_list	arguments

Returns

char* Buffer

References itoa(), memcpy(), memset(), strlen(), and uitoa().