String operations. More...

#include "generic.h"

Include dependency graph for stringop.h:

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Classes
struct	_VlEnumerator
	Member of an enumeration. More...
Enumerations
enum	{ VL_PROT_UNKNOWN = -1, VL_PROT_NONE = 0, VL_PROT_ASCII, VL_PROT_BINARY }
	File protocols. More...
Functions
VL_EXPORT vl_size	vl_string_basename (char destination, vl_size destinationSize, char const source, vl_size maxNumStrippedExtension)
	Extract base of file name.
VL_EXPORT int	vl_string_casei_cmp (const char string1, const char string2)
	Compare strings case-insensitive.
VL_EXPORT vl_size	vl_string_copy (char destination, vl_size destinationSize, char const source)
	Copy string.
VL_EXPORT vl_size	vl_string_copy_sub (char destination, vl_size destinationSize, char const beginning, char const *end)
	Copy substring.
VL_EXPORT char *	vl_string_find_char_rev (char const beginning, char const end, char c)
	Search character in reversed order.
VL_EXPORT vl_size	vl_string_length (char const *string)
	Calculate string length.
VL_EXPORT char *	vl_string_parse_protocol (char const string, int protocol)
	Extract the protocol prefix from a string.
VL_EXPORT char const *	vl_string_protocol_name (int prot)
	Get protocol name.
VL_EXPORT vl_size	vl_string_replace_wildcard (char destination, vl_size destinationSize, char const src, char wildcardChar, char escapeChar, char const *replacement)
	Replace wildcard characters by a string.
String enumerations
typedef struct _VlEnumerator	VlEnumerator
	Member of an enumeration.
VL_EXPORT VlEnumerator *	vl_enumeration_get (VlEnumerator const enumeration, char const name)
	Get a member of an enumeration by name.
VL_EXPORT VlEnumerator *	vl_enumeration_get_casei (VlEnumerator const enumeration, char const name)
	Get a member of an enumeration by name (case insensitive)
VL_EXPORT VlEnumerator *	vl_enumeration_get_by_value (VlEnumerator const *enumeration, vl_index value)
	Get a member of an enumeration by value.

Detailed Description

String operations.

Author:: Andrea Vedaldi

stringop.h implements basic string operations. All functions that write to strings use range checking, which makes them safer than some standard POSIX equivalent (see Detecting overflow).

Enumerations

stringop.h defines a simple enumeration data type. This is given by an array of enumeration members, represented by instances of the VlEnumerator strucutre, each storing a name-value pair. The enumeration must end by a member whose name is set to NULL.

Use vl_enumeration_get and vl_enumeration_get_casei to retrieve an enumeration member by name.

File protocols

stringop.h defines a few file "protocols" and helps parsing them from URL-like formatted strings. The supported protocols are:

File protocols
Protocol	Code	URL prefix
ASCII	VL_PROT_ASCII	`ascii://`
BINARY	VL_PROT_BINARY	`binary://`

Detecting overflow

stringop.h functions that write a string to a character buffer take both the buffer and its size n as input. If n is not large enough, the output may be truncated but it is always a null terminated string (provided that n >= 1). Such functions also return the length of the string that would have been written r (which does not include the terminating null character) had the buffer been large enough. Hence an overflow can be detected by testing if r >= n, r can be used to re-allocate a buffer large enough to contain the result, and the operation can be repeated.

Author:: Andrea Vedaldi

Definition in file stringop.h.

Typedef Documentation

typedef struct _VlEnumerator VlEnumerator

Member of an enumeration.

Enumeration Type Documentation

anonymous enum

File protocols.

Enumerator:

VL_PROT_UNKNOWN	unknown protocol
VL_PROT_NONE	no protocol
VL_PROT_ASCII	ASCII protocol
VL_PROT_BINARY	Binary protocol

Definition at line 20 of file stringop.h.

Function Documentation

VL_EXPORT VlEnumerator* vl_enumeration_get	(	VlEnumerator const *	enumeration,
		char const *	name
	)

Get a member of an enumeration by name.

Parameters:

enumeration	array of VlEnumerator objects.
name	the name of the desired member.

Returns:: enumerator matching name.

If name is not found in the enumeration, then the value NULL is returned.

See also:: vl-stringop-enumeration

Definition at line 409 of file stringop.c.

VL_EXPORT VlEnumerator* vl_enumeration_get_by_value	(	VlEnumerator const *	enumeration,
		vl_index	value
	)

Get a member of an enumeration by value.

Parameters:

enumeration	array of VlEnumerator objects.
value	value of the desired member.

Returns:: enumerator matching value.

If value is not found in the enumeration, then the value NULL is returned.

See also:: vl-stringop-enumeration

Definition at line 453 of file stringop.c.

VL_EXPORT VlEnumerator* vl_enumeration_get_casei	(	VlEnumerator const *	enumeration,
		char const *	name
	)

Get a member of an enumeration by name (case insensitive)

Parameters:

enumeration	array of VlEnumerator objects.
name	the name of the desired member.

Returns:: enumerator matching name.

If name is not found in the enumeration, then the value NULL is returned. string is matched case insensitive.

See also:: vl-stringop-enumeration

Definition at line 431 of file stringop.c.

VL_EXPORT vl_size vl_string_basename	(	char *	destination,
		vl_size	destinationSize,
		char const *	source,
		vl_size	maxNumStrippedExtensions
	)

Extract base of file name.

------------------------------------------------------------------

Parameters:

destination	destination buffer.
destinationSize	size of destination buffer.
source	input string.
maxNumStrippedExtensions	maximum number of extensions to strip.

Returns:: length of the destination string.

The function removes the leading path and up to maxNumStrippedExtensions trailing extensions from the string source and writes the result to the buffer destination.

The leading path is the longest suffix that ends with either the \ or / characters. An extension is a string starting with the . character not containing it. For instance, the string file.png contains the extension .png and the string file.tar.gz contains two extensions (.tar and .gz).

See also:: Detecting overflow.

Definition at line 163 of file stringop.c.

VL_EXPORT int vl_string_casei_cmp	(	const char *	string1,
		const char *	string2
	)

Compare strings case-insensitive.

------------------------------------------------------------------

Parameters:

string1	fisrt string.
string2	second string.

Returns:: an integer =,<,> 0 if string1 =,<,> string2

Definition at line 377 of file stringop.c.

VL_EXPORT vl_size vl_string_copy	(	char *	destination,
		vl_size	destinationSize,
		char const *	source
	)

Copy string.

------------------------------------------------------------------

Parameters:

destination	output buffer.
destinationSize	size of the output buffer.
source	string to copy.

Returns:: length of the source string.

The function copies the string source to the buffer destination of size destinationSize.

See also:: Detecting overflow.

Definition at line 274 of file stringop.c.

VL_EXPORT vl_size vl_string_copy_sub	(	char *	destination,
		vl_size	destinationSize,
		char const *	beginning,
		char const *	end
	)

Copy substring.

------------------------------------------------------------------

Parameters:

destination	output buffer.
destinationSize	size of output buffer.
beginning	start of the substring.
end	end of the substring.

Returns:: length of the destination string.

The function copies the substring from at beginning to end (not included) to the buffer destination of size destinationSize. If, however, the null character is found before end, the substring terminates there.

See also:: Detecting overflow.

Definition at line 311 of file stringop.c.

VL_EXPORT char* vl_string_find_char_rev	(	char const *	beginning,
		char const *	end,
		char	c
	)

Search character in reversed order.

------------------------------------------------------------------

Parameters:

beginning	pointer to the substring beginning.
end	pointer to the substring end.
c	character to search for.

Returns:: pointer to last occurrence of c, or 0 if none.

The function searches for the last occurrence of the character c in the substring from beg to end (the latter not being included).

Definition at line 345 of file stringop.c.

VL_EXPORT vl_size vl_string_length ( char const * string )

Calculate string length.

------------------------------------------------------------------

Parameters:

string string.

Returns:: string length.

Definition at line 362 of file stringop.c.

VL_EXPORT char* vl_string_parse_protocol	(	char const *	string,
		int *	protocol
	)

Extract the protocol prefix from a string.

------------------------------------------------------------------

Parameters:

string	string.
protocol	protocol code (output).

Returns:: pointer to the first character after the protocol prefix.

The function extracts the prefix of the string string terminated by the first occurrence of the :// substring (if any). It then matches the suffix terminated by :// to the supported File protocols protocols. If protocol is not NULL, the corresponding protocol code is written to protocol

The function writes to protocol the value VL_PROT_NONE if no suffix is detected and VL_PROT_UNKNOWN if there is a suffix but it cannot be matched to any of the supported protocols.

Definition at line 83 of file stringop.c.

VL_EXPORT char const* vl_string_protocol_name ( int protocol )

Get protocol name.

------------------------------------------------------------------

Parameters:

protocol protocol code.

Returns:: pointer protocol name string.

The function returns a pointer to a string containing the name of the protocol protocol (see the vl-file-protocols protocols list). If the protocol is unknown the function returns the empty string.

Definition at line 126 of file stringop.c.

VL_EXPORT vl_size vl_string_replace_wildcard	(	char *	destination,
		vl_size	destinationSize,
		char const *	source,
		char	wildcardChar,
		char	escapeChar,
		char const *	replacement
	)

Replace wildcard characters by a string.

------------------------------------------------------------------

Parameters:

destination	output buffer.
destinationSize	size of the output buffer.
source	input string.
wildcardChar	wildcard character.
escapeChar	escape character.
replacement	replacement string.

The function replaces the occurrence of the specified wildcard character wildcardChar by the string replacement. The result is written to the buffer destination of size destinationSize.

Wildcard characters may be escaped by preceding them by the esc character. More in general, anything following an occurrence of esc character is copied verbatim. To disable the escape characters simply set esc to 0.

Returns:: length of the result.

See also:: Detecting overflow.

Definition at line 214 of file stringop.c.

Classes

Enumerations

Functions

String enumerations

Detailed Description

Enumerations

File protocols

Detecting overflow

Typedef Documentation

Enumeration Type Documentation

Function Documentation