FileInfo Class Reference

#include <Pt/System/FileInfo.h>

Provides information about a node in the file-system. More...

Public Types
enum	Type {   Invalid = 0,   Directory = 1,   File = 2,   Link = 4 }
	File-node type. More...
enum	Perms {   NoPerms = 0,   OwnerRead = 0400,   OwnerWrite = 0200,   OwnerExec = 0100,   OwnerAll = 0700,   GroupRead = 040,   GroupWrite = 020,   GroupExec = 010,   GroupAll = 070,   OthersRead = 04,   OthersWrite = 02,   OthersExec = 01,   OthersAll = 07,   AllPerms = 0777,   SetUid = 04000,   SetGid = 02000,   StickyBit = 01000,   PermMask = 07777,   UnknownPerms = 0xFFFF }
	File permission flags. More...
enum	PermOptions {   PermReplace = 1,   PermAdd = 2,   PermRemove = 4,   PermNoFollow = 8 }
	Options for modifying permissions. More...

Public Member Functions
	FileInfo ()
	Default constructor.
	FileInfo (const Path &path)
	Constructs from the path.
	FileInfo (const Pt::String &path)
	Constructs from the path.
	FileInfo (const char *path)
	Constructs from the path.
	~FileInfo ()
	Destructor.
void	clear ()
	Clears the state.
const Path &	path () const
	Returns the full path of node in the file-system. More...
Pt::uint64_t	size () const
	Returns the file size.
Type	type () const
	Returns the file type.
Perms	permissions () const
	Returns the file permissions.

Static Public Member Functions
static Type	type (const Path &path)
	Returns the type of file at the path.
static Pt::uint64_t	size (const Path &path)
	Returns the size of the file in bytes.
static DateTime	lastModified (const Path &path)
	Returns the time when last modified.
static Perms	permissions (const Path &path)
	Returns the permissions of the file at the path.
static void	permissions (const Path &path, Perms prms, PermOptions opts=PermReplace)
	Sets the permissions of the file at the path. More...
static bool	exists (const Path &path)
	Returns true if a file or directory exists at the path.
static void	createFile (const Path &path)
	Creates a new file.
static void	createSymlink (const Path &target, const Path &link)
	Creates a symbolic link at link pointing to target.
static void	createHardlink (const Path &target, const Path &link)
	Creates a hard link at link pointing to target.
static void	createDirectory (const Path &path)
	Creates a new directory.
static void	createDirectories (const Path &path)
	Creates a new directory.
static void	resize (const Path &path, Pt::uint64_t n)
	Resizes a file.
static void	remove (const Path &path)
	Removes a file or directory.
static void	removeAll (const Pt::System::Path &path)
	Removes a directory and its contents.
static void	move (const Path &path, const Path &to)
	Moves a file or directory.

Related Functions
FileInfo::Perms	operator| (FileInfo::Perms a, FileInfo::Perms b)
	Bitwise OR for FileInfo permission flags.
FileInfo::Perms	operator& (FileInfo::Perms a, FileInfo::Perms b)
	Bitwise AND for FileInfo permission flags.
FileInfo::Perms	operator^ (FileInfo::Perms a, FileInfo::Perms b)
	Bitwise XOR for FileInfo permission flags.
FileInfo::Perms	operator~ (FileInfo::Perms a)
	Bitwise NOT for FileInfo permission flags.
FileInfo::Perms &	operator|= (FileInfo::Perms &a, FileInfo::Perms b)
	Bitwise OR assignment for FileInfo permission flags.
FileInfo::Perms &	operator&= (FileInfo::Perms &a, FileInfo::Perms b)
	Bitwise AND assignment for FileInfo permission flags.
FileInfo::PermOptions	operator| (FileInfo::PermOptions a, FileInfo::PermOptions b)
	Bitwise OR for FileInfo permission options.
bool	operator< (const FileInfo &a, const FileInfo &b)
	Compare two FileInfo objects.
bool	operator== (const FileInfo &a, const FileInfo &b)
	Compare two FileInfo objects.
bool	operator!= (const FileInfo &a, const FileInfo &b)
	Compare two FileInfo objects.

Detailed Description

The Pt::System::FileInfo class provides operations to query information about files and directories in the file system and to add, remove and modify them. FileInfo objects can be created with a path, are assignable, comparable and can be used as keys for e.g. std::map. The path needs not to refer to existing items in the file system, when a FileInfo object is constructed. It can be checked whether a file exists and what type of file it is, as shown in the following example:

Pt::System::Path path("/tmp/logout.txt");
Pt::System::FileInfo fi(path);
 
if( fi.type() == Pt::System::FileInfo::File )
{
    std::cout << fi.path().toLocal() << ": " << fi.size() << " bytes.\n";
}
else
{
    std::cout << fi.path().toLocal() << " is invalid.\n";
}

Most operations are available as non-member functions, so it is not neccessary to create temporary FileInfo objects. Only the paths to files or directories are required to perform file system operations. The next example illustrates some of the non-member functions for file operations:

try
{
    Pt::System::Path tmp1("/tmp/tmpfile1");
    Pt::System::Path tmp2("/tmp/tmpfile2");
 
    // create a temporary file
    Pt::System::FileInfo::createFile(tmp1);
 
    // move it to a new location
    Pt::System::FileInfo::move(tmp1, tmp2);
 
    // remove the file
    Pt::System::FileInfo::remove(tmp2);
}
catch(const Pt::System::AccessFailed& e)
{
    std::cerr << "file error: " << e.resource() << std::endl;
}

The code shown above creates a file, moves it to a new location and finally deletes it. If an operation fails, for example because the file could not be created, an exception of type AccessFailed is thrown. This is also the case for all other operations such as size(), createFile(), createDirectory(), resize() and remove(). The exception reports the name of the resource that could not be accessed.

Member Enumeration Documentation

Type

enum Type

Enumerator
Invalid	Invalid file type.
Directory	Directory.
File	Regular file.
Link	Symbolic link.

Perms

enum Perms

Enumerator
NoPerms	No permissions.
OwnerRead	Owner read permission.
OwnerWrite	Owner write permission.
OwnerExec	Owner execute permission.
OwnerAll	All owner permissions.
GroupRead	Group read permission.
GroupWrite	Group write permission.
GroupExec	Group execute permission.
GroupAll	All group permissions.
OthersRead	Others read permission.
OthersWrite	Others write permission.
OthersExec	Others execute permission.
OthersAll	All others permissions.
AllPerms	All basic permissions.
SetUid	Set-user-ID on execute.
SetGid	Set-group-ID on execute.
StickyBit	Sticky bit.
PermMask	All valid permission bits.
UnknownPerms	Permissions not known.

PermOptions

enum PermOptions

Enumerator
PermReplace	Replace permissions entirely.
PermAdd	Add permission bits.
PermRemove	Remove permission bits.
PermNoFollow	Do not follow symbolic links.

Member Function Documentation

path()

const Path& path

(

)

const

This method may return a relative path, or a fully qualified one depending on how this object was constructed.

permissions()

static void permissions ( const Path &  path, Perms  prms, PermOptions  opts = PermReplace  )

static

The opts parameter controls how the permissions are applied. Use PermReplace to set permissions exactly, PermAdd to add bits, or PermRemove to remove bits. Combine with PermNoFollow using bitwise OR to act on the symbolic link itself.