sbuild::mntstream Class Reference

Access mounts. More...

#include <sbuild-mntstream.h>

Collaboration diagram for sbuild::mntstream:

[legend]

List of all members.

Public Types
enum	error_code { MNT_OPEN, MNT_READ }
	Error codes. More...
typedef sbuild::custom_error < error_code >	error
	Exception type.
Public Member Functions
	mntstream (std::string const &file)
	The constructor.
virtual	~mntstream ()
	The destructor.
void	open (std::string const &file)
	Open a mount file for reading.
void	close ()
	Close the mount file.
bool	eof () const
	Check for End Of File.
bool	bad () const
	Check for errors.
	operator bool ()
	Check if the mntstream status is good.
bool	operator! ()
	Check if the mntstream status is bad.
Private Member Functions
void	read (int quantity=1)
	Read mntents from the underlying FILE stream into the data deque.
Private Attributes
std::string	file
	The file name.
FILE *	mntfile
	The underlying FILE stream.
std::deque< mntentry >	data
	A list of mntentries represents the mount file stream as a LIFO stack.
bool	error_status
	Error status.
bool	eof_status
	End of File status.
Friends
mntstream &	operator>> (mntstream &stream, mntentry &entry)
	The overloaded extraction operator.
Classes
struct	mntentry
	An entry in a mntstream. More...

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Detailed Description

Access mounts.

This is a wrapper around the setmntent(3), getmntent(3) and endmntent(3) functions, which are used to read a stream of "mntents" through multiple getmntent() calls.

mntstream calls setmntent() and endmntent() automatically, and represents each mntent as a mntstream::mntentry. Like reading from and istream by pulling data out with the >> "extraction operator", mntentries are also extracted from the mntstream with the >> operator.

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Member Typedef Documentation

typedef sbuild::custom_error<error_code> sbuild::mntstream::error

Exception type.

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Member Enumeration Documentation

enum sbuild::mntstream::error_code

Error codes.

Enumerator:

MNT_OPEN	Failed to open mount file.
MNT_READ	Failed to read mount file.

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Constructor & Destructor Documentation

mntstream::mntstream

(

std::string const &

file

)

The constructor.

Parameters:

file

the file to read.

mntstream::~mntstream

(

)

[virtual]

The destructor.

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Member Function Documentation

void mntstream::open

(

std::string const &

file

)

Open a mount file for reading.

This uses the openmnt(3) call to open the underlying FILE stream. Any previously open mount file is closed before opening the new one. The mntstream error state is set if the open fails, and an exception will be thrown.

Parameters:

file

the file to read.

See also:

close()

void mntstream::close

(

)

Close the mount file.

This uses the closemnt(3) call to close the underlying FILE stream. All cached data is deleted and the error state set until open() is called.

See also:

open()

bool mntstream::eof

(

)

const

Check for End Of File.

Note that the end of file status is only set adter a read fails, so this should be checked after each read.

Returns:

true if the mntstream is empty, otherwise false.

bool mntstream::bad

(

)

const

Check for errors.

If there is an error, the mntstream is unusable until the next open() call.

Returns:

true if the mntstream is in an error state, otherwise false.

mntstream::operator bool

(

)

Check if the mntstream status is good.

Returns:

true if the status is good (eof() and bad() both return false).

bool mntstream::operator!

(

)

Check if the mntstream status is bad.

Returns:

true if the status is bad (eof() or bad() return true).

void mntstream::read

(

int

quantity = 1

)

[private]

Read mntents from the underlying FILE stream into the data deque.

If the read fails, the error state will be set, and an exception will be thrown.

Parameters:

quantity

the number of mntents to read.

Todo:

Add mntentry constructor to do automatic struct mntent to mntentry conversion.

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Friends And Related Function Documentation

mntstream& operator>>	(	mntstream &	stream,
		mntentry &	entry
	)			[friend]

The overloaded extraction operator.

This is used to pull mntentries from a mntstream.

Parameters:

	stream	the mntstream to get input from.
	entry	the mntentry to set.

Returns:

the mntstream.

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Member Data Documentation

std::string sbuild::mntstream::file [private]

The file name.

FILE* sbuild::mntstream::mntfile [private]

The underlying FILE stream.

std::deque<mntentry> sbuild::mntstream::data [private]

A list of mntentries represents the mount file stream as a LIFO stack.

bool sbuild::mntstream::error_status [private]

Error status.

bool sbuild::mntstream::eof_status [private]

End of File status.

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The documentation for this class was generated from the following files:

• sbuild/sbuild-mntstream.h
• sbuild/sbuild-mntstream.cc

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