String routines

Modules
	C (POSIX) locale string functions
	snprintf implementations

Functions
int	apr_strnatcmp (char const *a, char const *b)
int	apr_strnatcasecmp (char const *a, char const *b)
char *	apr_pstrdup (apr_pool_t *p, const char *s)
char *	apr_pstrmemdup (apr_pool_t *p, const char *s, apr_size_t n)
char *	apr_pstrndup (apr_pool_t *p, const char *s, apr_size_t n)
void *	apr_pmemdup (apr_pool_t *p, const void *m, apr_size_t n)
char *	apr_pstrcat (apr_pool_t *p,...)
char *	apr_pstrcatv (apr_pool_t *p, const struct iovec *vec, apr_size_t nvec, apr_size_t *nbytes)
char *	apr_pvsprintf (apr_pool_t *p, const char *fmt, va_list ap)
char *	apr_psprintf (apr_pool_t *p, const char *fmt,...)
char *	apr_cpystrn (char *dst, const char *src, apr_size_t dst_size)
char *	apr_collapse_spaces (char *dest, const char *src)
apr_status_t	apr_tokenize_to_argv (const char *arg_str, char ***argv_out, apr_pool_t *token_context)
char *	apr_strtok (char *str, const char *sep, char **last)
char *	apr_itoa (apr_pool_t *p, int n)
char *	apr_ltoa (apr_pool_t *p, long n)
char *	apr_off_t_toa (apr_pool_t *p, apr_off_t n)
apr_status_t	apr_strtoff (apr_off_t *offset, const char *buf, char **end, int base)
apr_int64_t	apr_strtoi64 (const char *buf, char **end, int base)
apr_int64_t	apr_atoi64 (const char *buf)
char *	apr_strfsize (apr_off_t size, char *buf)

Detailed Description

Function Documentation

apr_atoi64()

apr_int64_t apr_atoi64

(

const char *

buf

)

parse a base-10 numeric string into a 64-bit numeric value. Equivalent to apr_strtoi64(buf, (char**)NULL, 10).

Parameters

buf	The string to parse

Returns

The numeric value of the string. On overflow, errno is set to ERANGE. On success, errno is set to 0.

apr_collapse_spaces()

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

Remove all whitespace from a string

Parameters

dest	The destination string. It is okay to modify the string in place. Namely dest == src
src	The string to rid the spaces from.

Returns

A pointer to the destination string's null terminator.

apr_cpystrn()

char* apr_cpystrn	(	char *	dst,
		const char *	src,
		apr_size_t	dst_size
	)

Copy up to dst_size characters from src to dst; does not copy past a NUL terminator in src, but always terminates dst with a NUL regardless.

Parameters

dst	The destination string
src	The source string
dst_size	The space available in dst; dst always receives NUL termination, so if src is longer than dst_size, the actual number of characters copied is dst_size - 1.

Returns

Pointer to the NUL terminator of the destination string, dst

Remarks

Note the differences between this function and strncpy():
 1) strncpy() doesn't always NUL terminate; apr_cpystrn() does.
 2) strncpy() pads the destination string with NULs, which is often 
    unnecessary; apr_cpystrn() does not.
 3) strncpy() returns a pointer to the beginning of the dst string;
    apr_cpystrn() returns a pointer to the NUL terminator of dst, 
    to allow a check for truncation.

apr_itoa()

char* apr_itoa	(	apr_pool_t *	p,
		int	n
	)

create a string representation of an int, allocated from a pool

Parameters

p	The pool from which to allocate
n	The number to format

Returns

The string representation of the number

apr_ltoa()

char* apr_ltoa	(	apr_pool_t *	p,
		long	n
	)

create a string representation of a long, allocated from a pool

Parameters

p	The pool from which to allocate
n	The number to format

Returns

The string representation of the number

apr_off_t_toa()

char* apr_off_t_toa	(	apr_pool_t *	p,
		apr_off_t	n
	)

create a string representation of an apr_off_t, allocated from a pool

Parameters

p	The pool from which to allocate
n	The number to format

Returns

The string representation of the number

apr_pmemdup()

void* apr_pmemdup	(	apr_pool_t *	p,
		const void *	m,
		apr_size_t	n
	)

Duplicate a block of memory.

Parameters

p	The pool to allocate from
m	The memory to duplicate
n	The number of bytes to duplicate

Returns

The new block of memory or NULL if m == NULL

apr_psprintf()

char* apr_psprintf	(	apr_pool_t *	p,
		const char *	fmt,
			...
	)

printf-style style printing routine. The data is output to a string allocated from a pool

Parameters

p	The pool to allocate out of
fmt	The format of the string
...	The arguments to use while printing the data

Returns

The new string

apr_pstrcat()

char* apr_pstrcat	(	apr_pool_t *	p,
			...
	)

Concatenate multiple strings, allocating memory out a pool

Parameters

p	The pool to allocate out of
...	The strings to concatenate. The final string must be NULL

Returns

The new string

apr_pstrcatv()

char* apr_pstrcatv	(	apr_pool_t *	p,
		const struct iovec *	vec,
		apr_size_t	nvec,
		apr_size_t *	nbytes
	)

Concatenate multiple strings specified in a writev-style vector

Parameters

p	The pool from which to allocate
vec	The strings to concatenate
nvec	The number of strings to concatenate
nbytes	(output) strlen of new string (pass in NULL to omit)

Returns

The new string

apr_pstrdup()

char* apr_pstrdup	(	apr_pool_t *	p,
		const char *	s
	)

duplicate a string into memory allocated out of a pool

Parameters

p	The pool to allocate out of
s	The string to duplicate

Returns

The new string or NULL if s == NULL

apr_pstrmemdup()

char* apr_pstrmemdup	(	apr_pool_t *	p,
		const char *	s,
		apr_size_t	n
	)

Create a null-terminated string by making a copy of a sequence of characters and appending a null byte

Parameters

p	The pool to allocate out of
s	The block of characters to duplicate
n	The number of characters to duplicate

Returns

The new string or NULL if s == NULL

Remarks

This is a faster alternative to apr_pstrndup(), for use when you know that the string being duplicated really has 'n' or more characters. If the string might contain fewer characters, use apr_pstrndup().

apr_pstrndup()

char* apr_pstrndup	(	apr_pool_t *	p,
		const char *	s,
		apr_size_t	n
	)

Duplicate at most n characters of a string into memory allocated out of a pool; the new string will be NUL-terminated

Parameters

p	The pool to allocate out of
s	The string to duplicate
n	The maximum number of characters to duplicate

Returns

The new string or NULL if s == NULL

Remarks

The amount of memory allocated from the pool is the length of the returned string including the NUL terminator

apr_pvsprintf()

char* apr_pvsprintf	(	apr_pool_t *	p,
		const char *	fmt,
		va_list	ap
	)

printf-style style printing routine. The data is output to a string allocated from a pool

Parameters

p	The pool to allocate out of
fmt	The format of the string
ap	The arguments to use while printing the data

Returns

The new string

apr_strfsize()

char* apr_strfsize	(	apr_off_t	size,
		char *	buf
	)

Format a binary size (magnitiudes are 2^10 rather than 10^3) from an apr_off_t, as bytes, K, M, T, etc, to a four character compacted human readable string.

Parameters

size	The size to format
buf	The 5 byte text buffer (counting the trailing null)

Returns

The buf passed to apr_strfsize()

Remarks

All negative sizes report ' - ', apr_strfsize only formats positive values.

apr_strnatcasecmp()

int apr_strnatcasecmp	(	char const *	a,
		char const *	b
	)

Do a natural order comparison of two strings ignoring the case of the strings.

Parameters

a	The first string to compare
b	The second string to compare

Returns

Either <0, 0, or >0. If the first string is less than the second this returns <0, if they are equivalent it returns 0, and if the first string is greater than second string it retuns >0.

apr_strnatcmp()

int apr_strnatcmp	(	char const *	a,
		char const *	b
	)

Do a natural order comparison of two strings.

Parameters

a	The first string to compare
b	The second string to compare

Returns

Either <0, 0, or >0. If the first string is less than the second this returns <0, if they are equivalent it returns 0, and if the first string is greater than second string it retuns >0.

apr_strtoff()

apr_status_t apr_strtoff	(	apr_off_t *	offset,
		const char *	buf,
		char **	end,
		int	base
	)

Convert a numeric string into an apr_off_t numeric value.

Parameters

offset	The value of the parsed string.
buf	The string to parse. It may contain optional whitespace, followed by an optional '+' (positive, default) or '-' (negative) character, followed by an optional '0x' prefix if base is 0 or 16, followed by numeric digits appropriate for base.
end	A pointer to the end of the valid character in buf. If not NULL, it is set to the first invalid character in buf.
base	A numeric base in the range between 2 and 36 inclusive, or 0. If base is zero, buf will be treated as base ten unless its digits are prefixed with '0x', in which case it will be treated as base 16.

Bug:

*end breaks type safety; where *buf is const, *end needs to be declared as const in APR 2.0

apr_strtoi64()

apr_int64_t apr_strtoi64	(	const char *	buf,
		char **	end,
		int	base
	)

parse a numeric string into a 64-bit numeric value

Parameters

buf	The string to parse. It may contain optional whitespace, followed by an optional '+' (positive, default) or '-' (negative) character, followed by an optional '0x' prefix if base is 0 or 16, followed by numeric digits appropriate for base.
end	A pointer to the end of the valid character in buf. If not NULL, it is set to the first invalid character in buf.
base	A numeric base in the range between 2 and 36 inclusive, or 0. If base is zero, buf will be treated as base ten unless its digits are prefixed with '0x', in which case it will be treated as base 16.

Returns

The numeric value of the string. On overflow, errno is set to ERANGE. On success, errno is set to 0.

apr_strtok()

char* apr_strtok	(	char *	str,
		const char *	sep,
		char **	last
	)

Split a string into separate null-terminated tokens. The tokens are delimited in the string by one or more characters from the sep argument.

Parameters

str	The string to separate; this should be specified on the first call to apr_strtok() for a given string, and NULL on subsequent calls.
sep	The set of delimiters
last	State saved by apr_strtok() between calls.

Returns

The next token from the string

Note

the 'last' state points to the trailing NUL char of the final token, otherwise it points to the character following the current token (all successive or empty occurances of sep are skiped on the subsequent call to apr_strtok). Therefore it is possible to avoid a strlen() determination, with the following logic; toklen = last - retval; if (*last) –toklen;

apr_tokenize_to_argv()

apr_status_t apr_tokenize_to_argv	(	const char *	arg_str,
		char ***	argv_out,
		apr_pool_t *	token_context
	)

Convert the arguments to a program from one string to an array of strings terminated by a NULL pointer

Parameters

arg_str	The arguments to convert
argv_out	Output location. This is a pointer to an array of strings.
token_context	Pool to use.