string.h File Reference

String and memory operations. More...

#include <core.h>

Go to the source code of this file.

Functions
size_t	strlen (const char *str)
	Return the length of a null-terminated string. More...
size_t	strlcpy (char *dst, const char *src, size_t dstsize)
	Copy the source string to the destination buffer. More...
size_t	strlcat (char *dst, const char *src, size_t dstsize)
	Append the source string to the end of the destination string. More...
int	strcmp (const char *str1, const char *str2)
	Compare two strings and return a value indicating their lexicographical order. More...
void *	memcpy (void *dst, const void *src, size_t num)
	Copy bytes from one memory region to another. More...
void *	memmove (void *dst, const void *src, size_t num)
	Move bytes from one memory region to another, even if the regions overlap. More...
void *	memset (void *dst, int b, size_t num)
	Fill a region of memory with a single byte value. More...
void *	memsetw (void *dst, int w, size_t num)
	Fill a region of memory with a single 16-bit word value. More...
void *	memsetd (void *dst, uint32_t d, size_t num)
	Fill a region of memory with a single 32-bit dword value. More...
void *	memzero (void *dst, size_t num)
	Fill a region of memory with zeroes. More...

Detailed Description

String and memory operations.

Definition in file string.h.

Function Documentation

size_t strlen

(

const char *

str

)

Return the length of a null-terminated string.

Count the number of characters in the null-terminated string and return the count.

Parameters

[in]

str

Pointer to a null-terminated string.

Returns

The number of characters preceding the null terminator.

Referenced by add_msg().

size_t strlcpy	(	char *	dst,
		const char *	src,
		size_t	dstsize
	)

Copy the source string to the destination buffer.

Appends string src to the end of dst. It will copy at most dstsize - 1 characters. A null terminator is added to the end of the destination string unless dstsize was 0.

Parameters

[in]	dst	Pointer to the destination buffer.
[in]	src	Pointer to the source string.
[in]	dstsize	Maximum number of characters in the dst buffer after copying, including the null terminator.

Returns

The length of the copied string after truncation.

size_t strlcat	(	char *	dst,
		const char *	src,
		size_t	dstsize
	)

Append the source string to the end of the destination string.

The function will append at most dstsize - strlen(dst) - 1 characters. A null terminator is added to the end of the concatenated string unless dstsize was 0.

Parameters

[in]	dst	Pointer to the destination string.
[in]	src	Pointer to the source string.
[in]	dstsize	Maximum number of characters in the dst buffer after concatenation, including the null terminator.

Returns

The length of the concatenated string after truncation.

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

Compare two strings and return a value indicating their lexicographical order.

String comparison continues until a null terminator is reached in one of the strings.

Parameters

[in]	str1	Pointer to the first string.
[in]	str2	Pointer to the second string.

Returns

< 0 if the first character in str1 that doesn't match a character in str2 has a lower value. = 0 if the two strings are identical. > 0 otherwise.

Referenced by cmp_cmds(), and command_exec().

void* memcpy	(	void *	dst,
		const void *	src,
		size_t	num
	)

Copy bytes from one memory region to another.

If the memory regions overlap, this function's behavior is undefined, and you should use memmove instead.

Parameters

[in]	dst	Address of the destination memory area.
[in]	src	Address of the source memory area.
[in]	num	Number of bytes to copy.

Returns

Destination address.

Referenced by add_msg(), kb_init(), kb_setlayout(), and tty_printchar().

void* memmove	(	void *	dst,
		const void *	src,
		size_t	num
	)

Move bytes from one memory region to another, even if the regions overlap.

Parameters

[in]	dst	Address of the destination memory area.
[in]	src	Address of the source memory area.
[in]	num	Number of bytes to copy.

Returns

Destination address.

Referenced by collapse(), insertafter(), and log_removecallback().

void* memset	(	void *	dst,
		int	b,
		size_t	num
	)

Fill a region of memory with a single byte value.

Parameters

[in]	dst	Address of the destination memory area.
[in]	b	Value of the byte used to fill memory.
[in]	num	Number of bytes to set.

Returns

Destination address.

void* memsetw	(	void *	dst,
		int	w,
		size_t	num
	)

Fill a region of memory with a single 16-bit word value.

Parameters

[in]	dst	Address of the destination memory area.
[in]	w	Value of the word used to fill memory.
[in]	num	Number of words to set.

Returns

Destination address.

Referenced by tty_clear(), and tty_printchar().

void* memsetd	(	void *	dst,
		uint32_t	d,
		size_t	num
	)

Fill a region of memory with a single 32-bit dword value.

Parameters

[in]	dst	Address of the destination memory area.
[in]	d	Value of the dword used to fill memory.
[in]	num	Number of dwords to set.

Returns

Destination address.

void* memzero	(	void *	dst,
		size_t	num
	)

Fill a region of memory with zeroes.

Parameters

[in]	dst	Address of the destination memory area.
[in]	num	Number of bytes to set to zero.

Returns

Destination address.

Referenced by alloc_page(), kb_init(), kmem_init(), page_init(), pagetable_destroy(), pfalloc(), pffree(), and pgalloc().