String Utility Functions

This section describes a number of utility functions for creating and manipulating strings, as well as other string-related stuff. More...

Functions
bool	Glib::str_has_prefix (const std::string & str, const std::string & prefix)
	Looks whether the string str begins with prefix.
bool	Glib::str_has_suffix (const std::string & str, const std::string & suffix)
	Looks whether the string str ends with suffix.
double	Glib::Ascii::strtod (const std::string & str)
	Converts a string to a double value.
double	Glib::Ascii::strtod (const std::string & str, std::string::size_type &end_index, std::string::size_type start_index=0)
	Converts a string to a double value.
std::string	Glib::Ascii::dtostr (double d)
	Converts a double to a string, using the '.
std::string	Glib::strescape (const std::string &source)
	Escapes all special characters in the string.
std::string	Glib::strescape (const std::string &source, const std::string & exceptions)
	Escapes all special characters in the string.
std::string	Glib::strcompress (const std::string &source)
	Replaces all escaped characters with their one byte equivalent.
Glib::ustring	Glib::strerror (int errnum)
	Returns a string corresponding to the given error code, e.g. "no such process".
Glib::ustring	Glib::strsignal (int signum)
	Returns a string describing the given signal, e.g. "Segmentation fault".

Detailed Description

This section describes a number of utility functions for creating and manipulating strings, as well as other string-related stuff.

Function Documentation

dtostr()

std::string Glib::Ascii::dtostr

(

double

d

)

Converts a double to a string, using the '.

' as decimal point.

This functions generates enough precision that converting the string back using Glib::Ascii::strtod() gives the same machine-number (on machines with IEEE compatible 64bit doubles).

Parameters

d	The double value to convert.

Returns

The converted string.

str_has_prefix()

bool Glib::str_has_prefix	(	const std::string &	str,
		const std::string &	prefix
	)

Looks whether the string str begins with prefix.

Parameters

str	A string.
prefix	The prefix to look for.

Returns

true if str begins with prefix, false otherwise.

str_has_suffix()

bool Glib::str_has_suffix	(	const std::string &	str,
		const std::string &	suffix
	)

Looks whether the string str ends with suffix.

Parameters

str	A string.
suffix	The suffix to look for.

Returns

true if str ends with suffix, false otherwise.

strcompress()

std::string Glib::strcompress

(

const std::string &

source

)

Replaces all escaped characters with their one byte equivalent.

This function does the reverse conversion of Glib::strescape().

Parameters

source

A string to compress.

Returns

A copy of source with all escaped characters compressed.

strerror()

Glib::ustring Glib::strerror

(

int

errnum

)

Returns a string corresponding to the given error code, e.g. "no such process".

This function is included since not all platforms support the strerror() function.

Parameters

errnum

The system error number. See the standard C errno documentation.

Returns

A string describing the error code. If the error code is unknown, "unknown error (<errnum>)" is returned.

strescape() [1/2]

std::string Glib::strescape

(

const std::string &

source

)

Escapes all special characters in the string.

Escapes the special characters '\b', '\f', '\n', '\r', '\t', '\' and '"' in the string source by inserting a '\' before them. Additionally all characters in the range 0x01 - 0x1F (everything below SPACE) and in the range 0x80 - 0xFF (all non-ASCII chars) are replaced with a '\' followed by their octal representation.

Glib::strcompress() does the reverse conversion.

Parameters

source

A string to escape.

Returns

A copy of source with certain characters escaped. See above.

strescape() [2/2]

std::string Glib::strescape	(	const std::string &	source,
		const std::string &	exceptions
	)

Escapes all special characters in the string.

Escapes the special characters '\b', '\f', '\n', '\r', '\t', '\' and '"' in the string source by inserting a '\' before them. Additionally all characters in the range 0x01 - 0x1F (everything below SPACE) and in the range 0x80 - 0xFF (all non-ASCII chars) are replaced with a '\' followed by their octal representation. Characters supplied in exceptions are not escaped.

Glib::strcompress() does the reverse conversion.

Parameters

source	A string to escape.
exceptions	A string of characters not to escape in source.

Returns

A copy of source with certain characters escaped. See above.

strsignal()

Glib::ustring Glib::strsignal

(

int

signum

)

Returns a string describing the given signal, e.g. "Segmentation fault".

This function is included since not all platforms support the strsignal() function.

Parameters

signum

The signal number. See the signal() documentation.

Returns

A string describing the signal. If the signal is unknown, "unknown signal (<signum>)" is returned.

strtod() [1/2]

double Glib::Ascii::strtod

(

const std::string &

str

)

Converts a string to a double value.

This function behaves like the standard strtod() function does in the C locale. It does this without actually changing the current locale, since that would not be thread-safe.

This function is typically used when reading configuration files or other non-user input that should be locale independent. To handle input from the user you should normally use locale-sensitive C++ streams.

To convert from a string to double in a locale-insensitive way, use Glib::Ascii::dtostr().

Parameters

str	The string to convert to a numeric value.

Returns

The double value.

Exceptions

std::overflow_error	Thrown if the correct value would cause overflow.
std::underflow_error	Thrown if the correct value would cause underflow.

strtod() [2/2]

double Glib::Ascii::strtod	(	const std::string &	str,
		std::string::size_type &	end_index,
		std::string::size_type	start_index = 0
	)

Converts a string to a double value.

This function behaves like the standard strtod() function does in the C locale. It does this without actually changing the current locale, since that would not be thread-safe.

This function is typically used when reading configuration files or other non-user input that should be locale independent. To handle input from the user you should normally use locale-sensitive C++ streams.

To convert from a string to double in a locale-insensitive way, use Glib::Ascii::dtostr().

Parameters

	str	The string to convert to a numeric value.
	start_index	The index of the first character that should be used in the conversion.
[out]	end_index	The index of the character after the last character used in the conversion.

Returns

The double value.

Exceptions

std::out_of_range	Thrown if start_index is out of range.
std::overflow_error	Thrown if the correct value would cause overflow.
std::underflow_error	Thrown if the correct value would cause underflow.