PTLib: PString Class Reference

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PINLINE PString::PString ( )

Construct an empty string. This will have one character in it which is the '' character.

PINLINE PString::PString ( const PString & str )

Create a new reference to the specified string. The string memory is not copied, only the pointer to the data.

Parameters:

str

String to create new reference to.

PINLINE PString::PString ( const std::string & str )

Create a new string from the specified std::string

PString::PString ( const char * cstr )

Create a string from the C string array. This is most commonly used with a literal string, eg "hello". A new memory block is allocated of a size sufficient to take the length of the string and its terminating '' character.

If UCS-2 is used then each char from the char pointer is mapped to a single UCS-2 character.

Parameters:

cstr

Standard '' terminated C string.

PString::PString ( const wchar_t * ustr )

Create a string from the UCS-2 string array. A new memory block is allocated of a size sufficient to take the length of the string and its terminating '' character.

Parameters:

ustr

UCS-2 null terminated string.

PString::PString	(	const char *	cstr,
		PINDEX	len
	)

Create a string from the array. A new memory block is allocated of a size equal to len# plus one which is sufficient to take the string and a terminating '' character.

If UCS-2 is used then each char from the char pointer is mapped to a single UCS-2 character.

Note that this function will allow a string with embedded '' characters to be created, but most of the functions here will be unable to access characters beyond the first ''. Furthermore, if the MakeMinimumSize()# function is called, all data beyond that first #''# character will be lost.

Parameters:

cstr	Pointer to a string of characters.
len	Length of the string in bytes.

PString::PString	(	const wchar_t *	ustr,
		PINDEX	len
	)

Create a string from the UCS-2 array. A new memory block is allocated of a size equal to len# plus one which is sufficient to take the string and a terminating '' character.

Note that this function will allow a string with embedded '' characters to be created, but most of the functions here will be unable to access characters beyond the first ''. Furthermore, if the MakeMinimumSize()# function is called, all data beyond that first #''# character will be lost.

Parameters:

ustr	Pointer to a string of UCS-2 characters.
len	Length of the string in bytes.

PString::PString ( const PWCharArray & ustr )

Create a string from the UCS-2 array. A new memory block is allocated of a size equal to len# plus one which is sufficient to take the string and a terminating '' character.

Note that this function will allow a string with embedded '' characters to be created, but most of the functions here will be unable to access characters beyond the first ''. Furthermore, if the MakeMinimumSize()# function is called, all data beyond that first #''# character will be lost.

Parameters:

ustr

UCS-2 null terminated string.

PINLINE PString::PString ( char ch )

Create a string from the single character. This is most commonly used as a type conversion constructor when a literal character, eg 'A' is used in a string expression. A new memory block is allocated of two characters to take the char and its terminating '' character.

If UCS-2 is used then the char is mapped to a single UCS-2 character.

Parameters:

ch	Single character to initialise string.

PString::PString ( short n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( unsigned short n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( int n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( unsigned int n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( long n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( unsigned long n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( PInt64 n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString ( PUInt64 n )

Create a string from the integer type. This will create a simple base 10, shortest length conversion of the integer (with sign character if appropriate) into the string.

Parameters:

n	Integer to convert

PString::PString	(	ConversionType	type,
		const char *	str,
			...
	)

Parameters:

type	Type of data source for conversion.
str	String to convert.

PString::PString	(	ConversionType	type,
		long	value,
		unsigned	base = `10`
	)

Parameters:

type	Type of data source for conversion.
value	Integer value to convert.
base	Number base to use for the integer conversion.

PString::PString	(	ConversionType	type,
		double	value,
		unsigned	places
	)

Parameters:

type	Type of data source for conversion.
value	Floating point value to convert.
places	Number of decimals in real number output.

PINLINE PString::PString	(	int	dummy,
		const PString *	str
	)			`[protected]`

PInt64 PString::AsInt64 ( unsigned base = 10 ) const

Convert the string to an integer value using the specified number base. All characters up to the first illegal character for the number base are converted. Case is not significant for bases greater than 10.

The number base may only be from 2 to 36 and the function will assert if it is not in this range.

This function uses the standard C library strtoq()# or strtoul()# function.

Returns:: integer value for the string.

Parameters:

base

Number base to convert the string in.

long PString::AsInteger ( unsigned base = 10 ) const

Convert the string to an integer value using the specified number base. All characters up to the first illegal character for the number base are converted. Case is not significant for bases greater than 10.

The number base may only be from 2 to 36 and the function will assert if it is not in this range.

This function uses the standard C library strtol()# function.

Returns:: integer value for the string.

Parameters:

base

Number base to convert the string in.

double PString::AsReal ( ) const

Convert the string to a floating point number. This number may be in decimal or exponential form. All characters up to the first illegal character for a floting point number are converted.

This function uses the standard C library strtod()# function.

Returns:: floating point value for the string.

PWCharArray PString::AsUCS2 ( ) const

Convert UTF-8 string to UCS-2. Note the resultant PWCharArray will have the trailing null included.

DWORD PString::AsUnsigned ( unsigned base = 10 ) const

Convert the string to an integer value using the specified number base. All characters up to the first illegal character for the number base are converted. Case is not significant for bases greater than 10.

The number base may only be from 2 to 36 and the function will assert if it is not in this range.

This function uses the standard C library strtoul()# function.

Returns:: integer value for the string.

Parameters:

base

Number base to convert the string in.

PUInt64 PString::AsUnsigned64 ( unsigned base = 10 ) const

Convert the string to an integer value using the specified number base. All characters up to the first illegal character for the number base are converted. Case is not significant for bases greater than 10.

The number base may only be from 2 to 36 and the function will assert if it is not in this range.

This function uses the standard C library strtouq()# or strtoul()# function.

Returns:: integer value for the string.

Parameters:

base

Number base to convert the string in.

virtual PObject* PString::Clone ( ) const [virtual]

Make a complete duplicate of the string. Note that the data in the array of characters is duplicated as well and the new object is a unique reference to that data.

Reimplemented from PBaseArray< T >.

Reimplemented in PCaselessString.

virtual Comparison PString::Compare ( const PObject & obj ) const [virtual]

Get the relative rank of the two strings. The system standard function, eg strcmp(), is used.

Returns:: comparison of the two objects, EqualTo# for same, LessThan# for obj# logically less than the object and GreaterThan# for obj# logically greater than the object.

Parameters:

obj

Other PString to compare against.

Reimplemented from PAbstractArray.

void PString::Delete	(	PINDEX	start,
		PINDEX	len
	)

Remove the substring from the string.

Note that this function will break the current instance from multiple references to the string. A new string buffer is allocated and the data from the old string buffer copied to it.

Parameters:

start	Position in string to remove.
len	Number of characters to delete.

PINLINE PString PString::Empty ( ) [static]

Return an empty string.

PINDEX PString::Find	(	const char *	cstr,
		PINDEX	offset = `0`
	)			const

Parameters:

cstr	C string to search for in string.
offset	Offset into string to begin search.

PINLINE PINDEX PString::Find	(	const PString &	str,
		PINDEX	offset = `0`
	)			const

Locate the position within the string of the substring.

Parameters:

str	String to search for in string.
offset	Offset into string to begin search.

PINDEX PString::Find	(	char	ch,
		PINDEX	offset = `0`
	)			const

Locate the position within the string of the character.

Parameters:

ch	Character to search for in string.
offset	Offset into string to begin search.

PINDEX PString::FindLast	(	const char *	cstr,
		PINDEX	offset = `P_MAX_INDEX`
	)			const

Locate the position of the last matching substring. Locate the position within the string of the last matching character or substring. The search will begin at the character offset provided, moving backward through the string.

If offset# is beyond the length of the string, then the search begins at the end of the string. If offset# is zero then the function always returns P_MAX_INDEX#.

The matching will be for identical character or string. If a search ignoring case is required then the string should be converted to a PCaselessString# before the search is made.

Returns:: position of character or substring in the string, or P_MAX_INDEX if the character or substring is not in the string.

Parameters:

cstr	C string to search for in string.
offset	Offset into string to begin search.

PINLINE PINDEX PString::FindLast	(	const PString &	str,
		PINDEX	offset = `P_MAX_INDEX`
	)			const

Locate the position of the last matching substring.

Parameters:

str	String to search for in string.
offset	Offset into string to begin search.

PINDEX PString::FindLast	(	char	ch,
		PINDEX	offset = `P_MAX_INDEX`
	)			const

Locate the position of the last matching character.

Parameters:

ch	Character to search for in string.
offset	Offset into string to begin search.

PINDEX PString::FindOneOf	(	const char *	cset,
		PINDEX	offset = `0`
	)			const

Locate the position of one of the characters in the set. The search will begin at the character offset provided.

If offset# is beyond the length of the string, then the function will always return P_MAX_INDEX#.

The matching will be for identical character or string. If a search ignoring case is required then the string should be converted to a PCaselessString# before the search is made.

Returns:: position of character in the string, or P_MAX_INDEX if no characters from the set are in the string.

Parameters:

cset	C string of characters to search for in string.
offset	Offset into string to begin search.

PINLINE PINDEX PString::FindOneOf	(	const PString &	set,
		PINDEX	offset = `0`
	)			const

Locate the position of one of the characters in the set.

Parameters:

set	String of characters to search for in string.
offset	Offset into string to begin search.

PBoolean PString::FindRegEx	(	const PRegularExpression &	regex,
		PINDEX &	pos,
		PINDEX &	len,
		PINDEX	offset = `0`,
		PINDEX	maxPos = `P_MAX_INDEX`
	)			const

Locate the position within the string of one of the regular expression. The search will begin at the character offset provided.

If offset# is beyond the length of the string, then the function will always return P_MAX_INDEX#.

Returns:: position of regular expression in the string, or P_MAX_INDEX if no characters from the set are in the string.

Parameters:

regex	regular expression to find
pos	Position of matched expression
len	Length of matched expression
offset	Offset into string to begin search.
maxPos	Maximum offset into string

PINDEX PString::FindRegEx	(	const PRegularExpression &	regex,
		PINDEX	offset = `0`
	)			const

Locate the position within the string of one of the regular expression. The search will begin at the character offset provided.

If offset# is beyond the length of the string, then the function will always return P_MAX_INDEX#.

Returns:: position of regular expression in the string, or P_MAX_INDEX if no characters from the set are in the string.

Parameters:

regex	regular expression to find
offset	Offset into string to begin search.

PINDEX PString::FindSpan	(	const char *	cset,
		PINDEX	offset = `0`
	)			const

Locate the position of character not in the set. The search will begin at the character offset provided.

If offset# is beyond the length of the string, or every character in the string is a member of the set, then the function will always return P_MAX_INDEX#.

The matching will be for identical character or string. If a search ignoring case is required then the string should be converted to a PCaselessString# before the search is made.

Returns:: position of character not in the set, or P_MAX_INDEX if all characters from the string are in the set.

Parameters:

cset	C string of characters to search for in string.
offset	Offset into string to begin search.

PINLINE PINDEX PString::FindSpan	(	const PString &	set,
		PINDEX	offset = `0`
	)			const

Locate the position of character not in the set.

Parameters:

set	String of characters to search for in string.
offset	Offset into string to begin search.

PINLINE PINDEX PString::GetLength ( ) const

Determine the length of the null terminated string. This is different from PContainer::GetSize()# which returns the amount of memory allocated to the string. This is often, though no necessarily, one larger than the length of the string.

Returns:: length of the null terminated string.

virtual PINDEX PString::HashFunction ( ) const [virtual]

Calculate a hash value for use in sets and dictionaries.

The hash function for strings will produce a value based on the sum of the first three characters of the string. This is a fairly basic function and make no assumptions about the string contents. A user may descend from PString and override the hash function if they can take advantage of the types of strings being used, eg if all strings start with the letter 'A' followed by 'B or 'C' then the current hash function will not perform very well.

Returns:: hash value for string.

Reimplemented from PObject.

virtual Comparison PString::InternalCompare	(	PINDEX	offset,
		PINDEX	length,
		const char *	cstr
	)			const `[protected, virtual]`

Reimplemented in PCaselessString.

virtual Comparison PString::InternalCompare	(	PINDEX	offset,
		char	c
	)			const `[protected, virtual]`

Reimplemented in PCaselessString.

void PString::InternalFromUCS2	(	const wchar_t *	ptr,
		PINDEX	len
	)			`[protected]`

virtual PBoolean PString::IsEmpty ( ) const [virtual]

Determine if the string is empty. This is semantically slightly different from the usual PContainer::IsEmpty()# function. It does not test for PContainer::GetSize()# equal to zero, it tests for GetLength()# equal to zero.

Returns:: PTrue if no non-null characters in string.

Reimplemented from PContainer.

PString PString::Left ( PINDEX len ) const

Extract a portion of the string into a new string. The original string is not changed and a new unique reference to a string is returned.

A substring from the beginning of the string for the number of characters specified is extracted.

If len# is greater than the length of the string then all characters to the end of the string are returned.

If len# is zero then an empty string is returned.

Returns:: substring of the source string.

Parameters:

len

Number of characters to extract.

PString PString::LeftTrim ( ) const

Create a string consisting of all characters from the source string except all spaces at the beginning of the string. The original string is not changed and a new unique reference to a string is returned.

Returns:: string with leading spaces removed.

PStringArray PString::Lines ( ) const

Split the string into individual lines. The line delimiters may be a carriage return (''), a line feed ('
') or a carriage return and line feed pair ("\r\n"). A line feed and carriage return pair ("\n\r") would yield a blank line. between the characters.

The Tokenise()# function should not be used to split a string into lines as a #"\r\n"# pair consitutes a single line ending. The Tokenise()# function would produce a blank line in between them.

Returns:: string array with a substring for each line in the string.

virtual PString& PString::MakeEmpty ( ) [virtual]

Make the current string empty

Reimplemented in PStringStream.

PINLINE PBoolean PString::MakeMinimumSize ( )

Set the actual memory block array size to the minimum required to hold the current string contents.

Note that this function will break the current instance from multiple references to the string. A new string buffer is allocated and the data from the old string buffer copied to it.

Returns:: PTrue if new memory block successfully allocated.

virtual PBoolean PString::MakeUnique ( ) [virtual]

Make this instance to be the one and only reference to the container contents. This implicitly does a clone of the contents of the container to make a unique reference. If the instance was already unique then the function does nothing.

Returns:: PTrue if the instance was already unique.

Reimplemented from PContainer.

PString PString::Mid	(	PINDEX	start,
		PINDEX	len = `P_MAX_INDEX`
	)			const

Extract a portion of the string into a new string. The original string is not changed and a new unique reference to a string is returned.

A substring from the start# position for the number of characters specified is extracted.

If len# is greater than the length of the string from the start# position then all characters to the end of the string are returned.

If start# is greater than the length of the string or len# is zero then an empty string is returned.

Returns:: substring of the source string.

Parameters:

start	Starting position of the substring.
len	Number of characters to extract.

Comparison PString::NumCompare	(	const char *	cstr,
		PINDEX	count = `P_MAX_INDEX`,
		PINDEX	offset = `0`
	)			const

Compare a string against a substring of the object. This will compare at most count# characters of the string, starting at the specified offset#, against that many characters of the str# parameter. If count# greater than the length of the str# parameter then the actual length of str# is used. If count# and the length of str# are greater than the length of the string remaining from the offset# then PFalse is returned.

Returns:: PTrue if str is a substring of .

Parameters:

cstr	C string object to compare against.
count	Number of chacracters in str to compare
offset	Offset into string to compare

Comparison PString::NumCompare	(	const PString &	str,
		PINDEX	count = `P_MAX_INDEX`,
		PINDEX	offset = `0`
	)			const

Compare a string against a substring of the object. This will compare at most count# characters of the string, starting at the specified offset#, against that many characters of the str# parameter. If count# greater than the length of the str# parameter then the actual length of str# is used. If count# and the length of str# are greater than the length of the string remaining from the offset# then PFalse is returned.

Returns:: PTrue if str is a substring of .

Parameters:

str	PString object to compare against.
count	Number of chacracters in str to compare
offset	Offset into string to compare

PString PString::operator & ( char ch ) const

Concatenate a single character to a PString to produce a third. The original string is not modified, an entirely new unique reference to a string is created. The ch# parameter is typically a literal, eg: {verbatim} myStr = aStr & '!'; {verbatim}

This function differes from operator+ in that it assures there is at least one space between the strings. Exactly one space is added if there is not a space at the end of the first or beggining of the last string.

Returns:: new string with concatenation of the object and parameter.

Parameters:

ch	Character to concatenate.

PString PString::operator & ( const char * cstr ) const

Concatenate a C string to a PString to produce a third. The original string is not modified, an entirely new unique reference to a string is created. The cstr# parameter is typically a literal string, eg: {verbatim} myStr = aStr & "fred"; {verbatim}

This function differes from operator+ in that it assures there is at least one space between the strings. Exactly one space is added if there is not a space at the end of the first or beggining of the last string.

Returns:: new string with concatenation of the object and parameter.

Parameters:

cstr

C string to concatenate.

PINLINE PString PString::operator & ( const PString & str ) const

Concatenate two strings to produce a third. The original strings are not modified, an entirely new unique reference to a string is created.

Returns:: new string with concatenation of the object and parameter.

Parameters:

str

String to concatenate.

PString& PString::operator &= ( char ch )

Concatenate a character to a PString, modifiying that string. The ch# parameter is typically a literal string, eg: {verbatim} myStr &= '!'; {verbatim}

This function differes from operator+ in that it assures there is at least one space between the strings. Exactly one space is added if there is not a space at the end of the first or beggining of the last string.

Returns:: reference to string that was concatenated to.

Parameters:

ch	Character to concatenate.

PString& PString::operator &= ( const char * cstr )

Concatenate a C string to a PString, modifiying that string. The cstr# parameter is typically a literal string, eg: {verbatim} myStr &= "fred"; {verbatim}

This function differes from operator+ in that it assures there is at least one space between the strings. Exactly one space is added if there is not a space at the end of the first or beggining of the last string.

Returns:: reference to string that was concatenated to.

Parameters:

cstr

C string to concatenate.

PINLINE PString & PString::operator &= ( const PString & str )

Concatenate a string to another string, modifiying that string.

Returns:: reference to string that was concatenated to.

Parameters:

str

String to concatenate.

bool PString::operator *= ( const char * cstr ) const

Compare a PString to a C string using a case insensitive compare function. The cstr# parameter is typically a literal string, eg: {verbatim} if (myStr == "fred") {verbatim}

Returns:: PTrue if equal.

Parameters:

cstr

C string to compare against.

PINLINE bool PString::operator *= ( const PString & str ) const

Compare two strings using case insensitive comparison.

Returns:: PTrue if equal.

Parameters:

str

PString object to compare against.

PINLINE PString::operator const unsigned char * ( ) const

Get the internal buffer as a pointer to unsigned characters. The standard "operator const char *" function is provided by the PCharArray# ancestor class.

Returns:: pointer to character buffer.

PString::operator std::string ( ) const [inline]

Cast the PString to a std::string

PINLINE bool PString::operator! ( ) const

Determine if the string is NOT empty. This is semantically identical to executing !IsEmpty() on the string.

Returns:: PTrue if non-null characters in string.

PINLINE bool PString::operator!= ( const char * cstr ) const

Compare a PString to a C string using the PObject::Compare()# function. The cstr# parameter is typically a literal string, eg: {verbatim} if (myStr != "fred") {verbatim}

Returns:: PTrue if not equal.

Parameters:

cstr

C string to compare against.

PINLINE bool PString::operator!= ( const PObject & str ) const

Compare two strings using the PObject::Compare()# function. This is identical to the PObject# class function but is necessary due to other overloaded versions.

Returns:: PTrue if not equal.

Parameters:

str

PString object to compare against.

Reimplemented from PObject.

PString PString::operator()	(	PINDEX	start,
		PINDEX	end
	)			const

Extract a portion of the string into a new string. The original string is not changed and a new unique reference to a string is returned.

The substring is returned inclusive of the characters at the start# and end# positions.

If the end# position is greater than the length of the string then all characters from the start# up to the end of the string are returned.

If start# is greater than the length of the string or end# is before start# then an empty string is returned.

Returns:: substring of the source string.

Parameters:

start	Starting position of the substring.
end	Ending position of the substring.

PString PString::operator+ ( char ch ) const

Concatenate a single character to a PString to produce a third. The original string is not modified, an entirely new unique reference to a string is created. The ch# parameter is typically a literal, eg: {verbatim} myStr = aStr + '!'; {verbatim}

Returns:: new string with concatenation of the object and parameter.

Parameters:

ch	Character to concatenate.

PString PString::operator+ ( const char * cstr ) const

Concatenate a C string to a PString to produce a third. The original string is not modified, an entirely new unique reference to a string is created. The cstr# parameter is typically a literal string, eg: {verbatim} myStr = aStr + "fred"; {verbatim}

Returns:: new string with concatenation of the object and parameter.

Parameters:

cstr

C string to concatenate.

PINLINE PString PString::operator+ ( const PString & str ) const

Concatenate two strings to produce a third. The original strings are not modified, an entirely new unique reference to a string is created.

Returns:: new string with concatenation of the object and parameter.

Parameters:

str

String to concatenate.

PString& PString::operator+= ( char ch )

Concatenate a single character to a PString. The ch# parameter is typically a literal, eg: {verbatim} myStr += '!'; {verbatim}

Returns:: new string with concatenation of the object and parameter.

Parameters:

ch	Character to concatenate.

Reimplemented in PFilePath.

PString& PString::operator+= ( const char * cstr )

Concatenate a C string to a PString, modifiying that string. The cstr# parameter is typically a literal string, eg: {verbatim} myStr += "fred"; {verbatim}

Returns:: reference to string that was concatenated to.

Parameters:

cstr

C string to concatenate.

Reimplemented in PFilePath.

PINLINE PString & PString::operator+= ( const PString & str )

Concatenate a string to another string, modifiying that string.

Returns:: reference to string that was concatenated to.

Parameters:

str

String to concatenate.

Reimplemented in PFilePath.

PINLINE bool PString::operator< ( const char * cstr ) const

Compare a PString to a C string using the PObject::Compare()# function. The cstr# parameter is typically a literal string, eg: {verbatim} if (myStr < "fred") {verbatim}

Returns:: PTrue if less than.

Parameters:

cstr

C string to compare against.

PINLINE bool PString::operator< ( const PObject & str ) const

Compare two strings using the PObject::Compare()# function. This is identical to the PObject# class function but is necessary due to other overloaded versions.

Returns:: PTrue if less than.

Parameters:

str

PString object to compare against.

Reimplemented from PObject.

PINLINE bool PString::operator<= ( const char * cstr ) const

Compare a PString to a C string using the PObject::Compare()# function. The cstr# parameter is typically a literal string, eg: {verbatim} if (myStr <= "fred") {verbatim}

Returns:: PTrue if less than or equal.

Parameters:

cstr

C string to compare against.

PINLINE bool PString::operator<= ( const PObject & str ) const

Compare two strings using the PObject::Compare()# function. This is identical to the PObject# class function but is necessary due to other overloaded versions.

Returns:: PTrue if less than or equal.

Parameters:

str

PString object to compare against.

Reimplemented from PObject.

PString& PString::operator= ( PUInt64 n )