C String Utilities

Functions
size_t	cstrLen (const char *s)
char *	cstrDup (const char *s)
size_t	cstrLenw (const unsigned short *s)
unsigned short *	cstrDupw (const unsigned short *s)
bool	cstrEq (const char *s1, const char *s2)
int	cstrCmp (const char *s1, const char *s2)
int	cstrCmpi (const char *s1, const char *s2)

Detailed Description

Portable C string helpers for common operations like length, duplication, and comparison. These functions use xalloc for memory allocation and provide optimized implementations.

Function Documentation

cstrCmp()

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

Compares two null-terminated strings.

Bytes are compared as unsigned, consistent with memcmp() and cstrCmpi(). Either string may be NULL, which sorts before any non-NULL string.

Parameters

s1	First null-terminated string, or NULL
s2	Second null-terminated string, or NULL

Returns

0 if the strings are equal, negative if s1 < s2, positive if s1 > s2

Example:

if (cstrCmp(a, b) < 0)
    ...

cstrCmpi()

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

Case-insensitive string comparison.

Compares two strings ignoring case differences.

Parameters

s1	First null-terminated string
s2	Second null-terminated string

Returns

0 if strings are equal (ignoring case), negative if s1 < s2, positive if s1 > s2

cstrDup()

char * cstrDup

(

const char *

s

)

Duplicate a null-terminated C string.

Allocates memory using xaAlloc and copies the string. The returned string must be freed with xaFree() or xaDestroy().

Parameters

s	Null-terminated string to duplicate, or NULL

Returns

Newly allocated copy of the string, or NULL if input was NULL

Referenced by xa_strdup().

cstrDupw()

unsigned short * cstrDupw

(

const unsigned short *

s

)

Duplicate a null-terminated wide character string.

Allocates memory using xaAlloc and copies the wide string. The returned string must be freed with xaFree() or xaDestroy().

Parameters

s	Null-terminated wide string to duplicate, or NULL

Returns

Newly allocated copy of the wide string, or NULL if input was NULL

cstrEq()

bool cstrEq	(	const char *	s1,
		const char *	s2
	)

Tests two null-terminated strings for equality.

Either string may be NULL, which compares equal only to another NULL.

Parameters

s1	First null-terminated string, or NULL
s2	Second null-terminated string, or NULL

Returns

true if the strings have identical contents

Example:

if (cstrEq(name, "width"))
    ...

cstrLen()

size_t cstrLen

(

const char *

s

)

Efficiently compute the length of a null-terminated C string.

This uses an optimized word-aligned algorithm for better performance than standard strlen on most architectures.

Parameters

s	Null-terminated string

Returns

Length of the string in bytes (excluding null terminator)

cstrLenw()

size_t cstrLenw

(

const unsigned short *

s

)

Compute the length of a null-terminated wide character string.

Parameters

s	Null-terminated wide string (unsigned short)

Returns

Length of the string in characters (excluding null terminator)