The os_file_system class is comprised wholly of static functions for access and manipulation of information associated with a particular path in a file system.

Interface

exists

/* static */ bool exists( const string& path , enum Encoding enc = Ascii )

Returns true if path is accessible by the current process; that is, if the directories mentioned in path exist and can be searched, and the rightmost name (the final directory name or the file name) exists. Default enc is Ascii. Valid value for enc can be Ascii or Utf8.

remove

/* static */ void remove( const string& path , enum Encoding enc = Ascii)

Removes path from the file system. Operates on regular files, directories, and some special files. It calls os_io_status which can raise os_io_tollkit_error::system_call_failure. Default enc is Ascii. Valid value for enc can be Ascii or Utf8.

remove_if_exists

/* static */ void remove_if_exists( const string& path , enum Encoding enc = Ascii)

If path exists, removes it. Checks for the existence of path and conditionally calls remove . Unlike remove() , this function does not generate errors if path does not exist; however, events for other conditions, such as permissions, can occur. Default enc is Ascii. Valid value for enc can be Ascii or Utf8.

Throws: os_file_toolkit_error

rename

/* static */ void rename( const string& from , const string& to , enum Encoding enc = Ascii)

Renames the path from from to to . Whether or not this function permits a different file system destination is implementation-dependent. Default enc is Ascii. Valid value for enc can be Ascii or Utf8.

Throws: os_file_toolkit_error

resize

/* static */ void resize( const string& path , os_off_t length )

Resizes path to length bytes. If the length of the file is less than length bytes, the call attempts to increase the file size. Note that this function is implementation-dependent. When this function is allowed, the gap in the resulting file will read as zeros. This function is only valid for paths to regular files.

Throws: os_file_toolkit_error

status

/* static */ os_io_status status( const string& path )

Returns the status associated with path . See class os_io_status for more information.

Throws: os_file_toolkit_error

UNIX-Specific Interface

executable

/* static */ bool executable( const string& path )

Tests whether path has execute permission based on the real rather than the effective user and group IDs.

limit

/* static */ long limit( const string& path , int limit )

Returns the limit of type limit associated with path . This function is a wrapper around the pathconf system call. Consult your UNIX documentation for the various values of limit .

Throws: os_file_toolkit_error

link

/* static */ void link( const string& to , const string& from )

Creates a hard link or duplicate entry to the same inode from from to to .

Throws: os_file_toolkit_error

readable

/* static */ bool readable( const string& path )

Returns true if the permissions for path indicate readability based on the real rather than the effective user ID and group.

symbolic_link

/* static */ string symbolic_link( const string& path )

Returns the path associated with the symbolic link named by path . A system error is generated if path is not the name of a symbolic link or is not accessible.

Note that this function has a hard-coded limit for the return value length. If the limit is insufficient, a system error is generated. To alter the limit, change the value of max_path_length in <ospace/file/filesys.h> and recompile the library.

Throws: os_file_toolkit_error

symbolic_link

/* static */ void symbolic_link( const string& to , const string& from )

Creates a symbolic link from from to to .

Throws: os_file_toolkit_error

symbolic_link_status

/* static */ os_io_status symbolic_link_status( const string& path )

This function is the same as status() . However, when path refers to a symbolic link the status is returned for the link.

Throws: os_file_toolkit_error

writable

/* static */ bool writable( const string& path )

Returns true if the user has permissions to write to path based on the real rather than the effective user ID and group.

file_system

Library

Declaration

Interface

UNIX-Specific Interface