NAME¶

FBB::Errno - Throwable objects handling error conditions

SYNOPSIS¶

#include <bobcat/errno> Linking option: -lbobcat

DESCRIPTION¶

FBB::Errno objects may be thrown in exceptions. As they are also std::ostringstream objects, information may be inserted into them. Facilitities are offered to insert information into, and to throw anonymous FBB::Errno objects. Errno exceptions may be thrown by several Bobcat classes. These classes are Arg, ArgConfig, BigInt, Cidr, ClientSocket, CmdFinder, CmdFinderBase, ConfigFile, DateTime, DecryptBuf, DigestBuf, EncryptBuf, Fork, GetHostent, Glob, HMacBuf, Hostname, InetAddress, level, LocalClientSocket, LocalServerSocket, LocalSocketBase, Log, MailHeaders, Mbuf, Milter, Mstream, OFoldStream, OFoldStreambuf, OneKey, Pattern, Pipe, Process, Redirector, Selector, ServerSocket, SocketBase, Stat, TempStream, User, Xpointer

NAMESPACE¶

FBB All constructors, members, operators and manipulators, mentioned in this man-page, are defined in the namespace FBB.

INHERITS FROM¶

std::ostringstream, std::exception

CONSTRUCTORS¶

o

Errno():

 

This constructor stores the current system errno value and its textual interpretation. No textual errno conversion is stored if errno equals 0.

o

Errno(char const *prefix):

 

This constructor stores the current system errno value. To this, the textual interpretation of errno is added unless errno equals 0. If, in this situation, prefix is a non-empty string, the text : is first appended to the prefix.

o

Errno(int errnr, char const *text = 0):

 

This constructor stores the provided errnr value, and the text text. The text argument may be omitted or empty, in which case no text will be prefixed to any additionally inserted information. With this version of FBB::Errno, no : is added to a non-empty text argument. The copy constructor is available.

MEMBER FUNCTIONS¶

All members of std::ostringstream and std::exception are available, as FBB::Errno inherits from these classes.

o

char const *why() const:

 

Returns the initialized and inserted text. No separators are inserted by the FBB::Errno object between the initializatin text and any text inserted later. If separators are required, the user of the FBB::Errno object must insert these explicitly. The same text is returned by char const *what() const, which is part of std::exception’s interface.

o

int which() const:

 

Returns the internally stored errno value: either the system-errno value, or the value provided by the third constructor.

 

OVERLOADED OPERATORS¶

o

Errno const &operator<<(Errno const &in, Type const &t):

 

This overloaded insertion operator can be used to insert values of any type that can also be inserted into an ostringstream object. It is implemented as a template, with the generic Type representing the type of the value to be inserted. The overloaded assignment operator is not available.

STATIC MEMBERS¶

The following convenience functions can be used for controlled opening of std::istream, std::ostream and std::fstream objects. If opening fails an FBB::Errno(1) exception is thrown containing a short message stating that the named stream could not be opened. If the stream was already open it is closed first.

o

static void open(std::ifstream &in, std::string const &name, std::ios::openmode mode = std::ios::in):

 

Convenience function opening the object ifstream in refers to.

o

static void open(std::ofstream &out, std::string const &name, std::ios::openmode mode = std::ios::out):

 

Convenience function opening (creating) the object ofstream out refers to.

o

static void open(std::fstream &out, std::string const &name, std::ios::openmode mode):

 

Convenience function opening the object fstream out refers to.

 

EXAMPLE¶

The following example shows the normal use of the manipulators:

    if (exceptionalCondition)
        throw FBB::Errno(1, "Failure") << ": Exceptional condition occurred";
        

FILES¶

bobcat/errno - defines the class interface

SEE ALSO¶

bobcat(7)

BUGS¶

None Reported.

DISTRIBUTION FILES¶

o

bobcat_3.01.00-x.dsc: detached signature;

o

bobcat_3.01.00-x.tar.gz: source archive;

o

bobcat_3.01.00-x_i386.changes: change log;

o

libbobcat1_3.01.00-x_*.deb: debian package holding the libraries;

o

libbobcat1-dev_3.01.00-x_*.deb: debian package holding the libraries, headers and manual pages;

o

http://sourceforge.net/projects/bobcat: public archive location;

 

BOBCAT¶

Bobcat is an acronym of `Brokken’s Own Base Classes And Templates’.

COPYRIGHT¶

This is free software, distributed under the terms of the GNU General Public License (GPL).

AUTHOR¶

Frank B. Brokken ( f.b.brokken@rug.nl).