Documentation

createDirectory dir creates a new directory dir which is initially empty, or as near to empty as the operating system allows.

The operation may fail with:

• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EROFS, EACCES]
• isAlreadyExistsError / AlreadyExists The operand refers to a directory that already exists. [EEXIST]
• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument The operand is not a valid directory name. [ENAMETOOLONG, ELOOP]
• NoSuchThing There is no path to the directory. [ENOENT, ENOTDIR]
• ResourceExhausted Insufficient resources (virtual memory, process file descriptors, physical disk space, etc.) are available to perform the operation. [EDQUOT, ENOSPC, ENOMEM, EMLINK]
• InappropriateType The path refers to an existing non-directory object. [EEXIST]

removeDirectory dir removes an existing directory dir. The implementation may specify additional constraints which must be satisfied before a directory can be removed (e.g. the directory has to be empty, or may not be in use by other processes). It is not legal for an implementation to partially remove a directory unless the entire directory is removed. A conformant implementation need not support directory removal in all situations (e.g. removal of the root directory).

The operation may fail with:

• HardwareFault A physical I/O error has occurred. EIO
• InvalidArgument The operand is not a valid directory name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The directory does not exist. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EROFS, EACCES, EPERM]
• UnsatisfiedConstraints Implementation-dependent constraints are not satisfied. [EBUSY, ENOTEMPTY, EEXIST]
• UnsupportedOperation The implementation does not support removal in this situation. [EINVAL]
• InappropriateType The operand refers to an existing non-directory object. [ENOTDIR]

removeFile file removes the directory entry for an existing file file, where file is not itself a directory. The implementation may specify additional constraints which must be satisfied before a file can be removed (e.g. the file may not be in use by other processes).

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument The operand is not a valid file name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The file does not exist. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EROFS, EACCES, EPERM]
• UnsatisfiedConstraints Implementation-dependent constraints are not satisfied. [EBUSY]
• InappropriateType The operand refers to an existing directory. [EPERM, EINVAL]

renameDirectory old new changes the name of an existing directory from old to new. If the new directory already exists, it is atomically replaced by the old directory. If the new directory is neither the old directory nor an alias of the old directory, it is removed as if by removeDirectory. A conformant implementation need not support renaming directories in all situations (e.g. renaming to an existing directory, or across different physical devices), but the constraints must be documented.

On Win32 platforms, renameDirectory fails if the new directory already exists.

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument Either operand is not a valid directory name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The original directory does not exist, or there is no path to the target. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EROFS, EACCES, EPERM]
• ResourceExhausted Insufficient resources are available to perform the operation. [EDQUOT, ENOSPC, ENOMEM, EMLINK]
• UnsatisfiedConstraints Implementation-dependent constraints are not satisfied. [EBUSY, ENOTEMPTY, EEXIST]
• UnsupportedOperation The implementation does not support renaming in this situation. [EINVAL, EXDEV]
• InappropriateType Either path refers to an existing non-directory object. [ENOTDIR, EISDIR]

renameFile old new changes the name of an existing file system object from old to new. If the new object already exists, it is atomically replaced by the old object. Neither path may refer to an existing directory. A conformant implementation need not support renaming files in all situations (e.g. renaming across different physical devices), but the constraints must be documented.

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument Either operand is not a valid file name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The original file does not exist, or there is no path to the target. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EROFS, EACCES, EPERM]
• ResourceExhausted Insufficient resources are available to perform the operation. [EDQUOT, ENOSPC, ENOMEM, EMLINK]
• UnsatisfiedConstraints Implementation-dependent constraints are not satisfied. [EBUSY]
• UnsupportedOperation The implementation does not support renaming in this situation. [EXDEV]
• InappropriateType Either path refers to an existing directory. [ENOTDIR, EISDIR, EINVAL, EEXIST, ENOTEMPTY]

getDirectoryContents dir returns a list of all entries in dir.

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument The operand is not a valid directory name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The directory does not exist. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EACCES]
• ResourceExhausted Insufficient resources are available to perform the operation. [EMFILE, ENFILE]
• InappropriateType The path refers to an existing non-directory object. [ENOTDIR]

If the operating system has a notion of current directories, getCurrentDirectory returns an absolute path to the current directory of the calling process.

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• isDoesNotExistError / NoSuchThing There is no path referring to the current directory. [EPERM, ENOENT, ESTALE...]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EACCES]
• ResourceExhausted Insufficient resources are available to perform the operation.
• UnsupportedOperation The operating system has no notion of current directory.

Note that in a concurrent program, the current directory is global state shared between all threads of the process. When using filesystem operations from multiple threads, it is therefore highly recommended to use absolute rather than relative FilePaths.

If the operating system has a notion of current directories, setCurrentDirectory dir changes the current directory of the calling process to dir.

The operation may fail with:

• HardwareFault A physical I/O error has occurred. [EIO]
• InvalidArgument The operand is not a valid directory name. [ENAMETOOLONG, ELOOP]
• isDoesNotExistError / NoSuchThing The directory does not exist. [ENOENT, ENOTDIR]
• isPermissionError / PermissionDenied The process has insufficient privileges to perform the operation. [EACCES]
• UnsupportedOperation The operating system has no notion of current directory, or the current directory cannot be dynamically changed.
• InappropriateType The path refers to an existing non-directory object. [ENOTDIR]

Note that in a concurrent program, the current directory is global state shared between all threads of the process. When using filesystem operations from multiple threads, it is therefore highly recommended to use absolute rather than relative FilePaths.

The operation doesFileExist returns True if the argument file exists and is not a directory, and False otherwise.

The operation doesDirectoryExist returns True if the argument file exists and is a directory, and False otherwise.

The getModificationTime operation returns the clock time at which the file or directory was last modified.

The operation may fail with:

• isPermissionError if the user is not permitted to access the modification time; or
• isDoesNotExistError if the file or directory does not exist.