string.h File Reference

#include <types.h>

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Functions
char *	strcpy (char *dest, const char *src) OLDCALL PRESERVES_REGS(b
int	strcmp (const char *s1, const char *s2) OLDCALL PRESERVES_REGS(b
void *	memcpy (void *dest, const void *src, size_t len)
void *	memmove (void *dest, const void *src, size_t n)
void *	memset (void *s, int c, size_t n) OLDCALL PRESERVES_REGS(b
char *	reverse (char *s) OLDCALL PRESERVES_REGS(b
char *	strcat (char *s1, const char *s2)
int	strlen (const char *s) OLDCALL PRESERVES_REGS(b
char *	strncat (char *s1, const char *s2, int n)
int	strncmp (const char *s1, const char *s2, int n)
char *	strncpy (char *s1, const char *s2, int n)
int	memcmp (const void *buf1, const void *buf2, size_t count) OLDCALL

Variables
char	c

Detailed Description

Generic string functions.

Function Documentation

strcpy()

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

Copies the string pointed to by src (including the terminating ‘\0’ character) to the array pointed to by dest.

The strings may not overlap, and the destination string dest must be large enough to receive the copy.

Parameters

dest	Array to copy into
src	Array to copy from

Returns

A pointer to dest

strcmp()

int strcmp	(	const char *	s1,
		const char *	s2
	)

Compares strings

Parameters

s1	First string to compare
s2	Second string to compare

Returns:

• > 0 if s1 > s2
• 0 if s1 == s2
• < 0 if s1 < s2

memcpy()

void* memcpy	(	void *	dest,
		const void *	src,
		size_t	len
	)

Copies n bytes from memory area src to memory area dest.

The memory areas may not overlap.

Parameters

dest	Buffer to copy into
src	Buffer to copy from
len	Number of Bytes to copy

memmove()

void* memmove	(	void *	dest,
		const void *	src,
		size_t	n
	)

Copies n bytes from memory area src to memory area dest, areas may overlap

memset()

void* memset	(	void *	s,
		int	c,
		size_t	n
	)

Fills the memory region s with n bytes using value c

Parameters

s	Buffer to fill
c	char value to fill with (truncated from int)
n	Number of bytes to fill

reverse()

char* reverse

(

char *

s

)

Reverses the characters in a string

Parameters

s	Pointer to string to reverse.

For example 'abcdefg' will become 'gfedcba'.

Banked as the string must be modifiable.

Returns: Pointer to s

strcat()

char* strcat	(	char *	s1,
		const char *	s2
	)

Concatenate Strings. Appends string s2 to the end of string s1

Parameters

s1	String to append onto
s2	String to copy from

For example 'abc' and 'def' will become 'abcdef'.

String s1 must be large enough to store both s1 and s2.

Returns: Pointer to s1

strlen()

int strlen

(

const char *

s

)

Calculates the length of a string

Parameters

s	String to calculate length of

Returns: Length of string not including the terminating ‘\0’ character.

strncat()

char* strncat	(	char *	s1,
		const char *	s2,
		int	n
	)

Concatenate at most n characters from string s2 onto the end of s1.

Parameters

s1	String to append onto
s2	String to copy from
n	Max number of characters to copy from s2

String s1 must be large enough to store both s1 and n characters of s2

Returns: Pointer to s1

strncmp()

int strncmp	(	const char *	s1,
		const char *	s2,
		int	n
	)

Compare strings (at most n characters):

Parameters

s1	First string to compare
s2	Second string to compare
n	Max number of characters to compare

Returns zero if the strings are identical, or non-zero if they are not (see below).

Returns:

• > 0 if s1 > s2 (at first non-matching byte)
• 0 if s1 == s2
• < 0 if s1 < s2 (at first non-matching byte)

strncpy()

char* strncpy	(	char *	s1,
		const char *	s2,
		int	n
	)

Copy n characters from string s2 to s1

Parameters

s1	String to copy into
s2	String to copy from
n	Max number of characters to copy from s2

If s2 is shorter than n, the remaining bytes in s1 are filled with \0.

Warning: If there is no \0 in the first n bytes of s2 then s1 will not be null terminated.

Returns: Pointer to s1

memcmp()

int memcmp	(	const void *	buf1,
		const void *	buf2,
		size_t	count
	)

Compare up to count bytes in buffers buf1 and buf2

Parameters

buf1	Pointer to First buffer to compare
buf2	Pointer to Second buffer to compare
count	Max number of bytes to compare

Returns zero if the buffers are identical, or non-zero if they are not (see below).

Returns:

• > 0 if buf1 > buf2 (at first non-matching byte)
• 0 if buf1 == buf2
• < 0 if buf1 < buf2 (at first non-matching byte)

Variable Documentation

c

void c