FileSystem¶
Usage
use FileSystem;
A file utilities library
The FileSystem module focuses on file and directory properties and
operations. It does not cover every interaction involving a file--- for
instance, path-specific operations live in the Path
module, while
routines for opening, writing to, or reading from a file live in the
IO
module. Rather, it covers cases where the user would prefer a file
or directory to be handled wholesale and/or with minimal interaction. For
example, this module contains File/Directory Manipulations and functions for determining
the File/Directory Properties. Also included are operations relating to the current
process's file system state, which are performed on a specified locale
(Locale State Functionality). The module also contains iterators for traversing the
file system (File System Traversal Iterators).
File/Directory Manipulations¶
copy
copyFile
copyTree
mkdir
moveDir
remove
rmTree
symlink
chmod
chown
copyMode
rename
File/Directory Properties¶
getGID
getMode
getFileSize
getUID
exists
isDir
isFile
isLink
isMount
sameFile
Locale State Functionality¶
Constant and Function Definitions¶
-
const
S_IRUSR
: int¶ S_IRUSR and the following constants are values of the form S_I[R | W | X][USR | GRP | OTH], S_IRWX[U | G | O], S_ISUID, S_ISGID, or S_ISVTX, where R corresponds to readable, W corresponds to writable, X corresponds to executable, USR and U correspond to user, GRP and G correspond to group, OTH and O correspond to other, directly tied to the C idea of these constants as visible at GNU Permissions. They are intended for use when dealing with the permissions of files or directories, such as with
chmod
,getMode
,mkdir
, orumask
S_IRUSR refers to the user's read permission
-
const
S_IRWXG
: int¶ Refers to all the permissions - read, write, and execute - of those in this group, see
S_IRUSR
-
const
S_IRWXO
: int¶ Refers to all the permissions - read, write, and execute - of everyone else, see
S_IRUSR
-
const
S_ISUID
: int¶ Use of this would cause the user id to be set on execution. See GNU Permissions for what that generally means, and
S_IRUSR
for intended uses, etc.
-
const
S_ISGID
: int¶ Use of this would cause the group id to be set on execution. See GNU Permissions for what that generally means, and
S_IRUSR
for intended uses, etc.
-
const
S_ISVTX
: int¶ This is the sticky bit. See GNU Permissions for what that generally means, and
S_IRUSR
for intended uses, etc.
-
proc
locale.
chdir
(name: string) throws¶ Change the current working directory of the locale in question to the specified path name.
Will halt with an error message if one is detected.
Warning
This is not safe within a parallel context. A chdir call in one task will affect the current working directory of all tasks for that locale.
Arguments: name : string -- The intended current working directory
-
proc
chmod
(name: string, mode: int) throws¶ Set the permissions of the file or directory specified by the argument name to that indicated by the argument mode.
Will halt with an error message if one is detected
Arguments: - name : string -- The name of the file or directory whose permissions should be altered.
- mode : int -- The permissions desired for the file or directory in question.
See description of
S_IRUSR
, for instance, for potential values.
-
proc
chown
(name: string, uid: int, gid: int) throws¶ Change one or both of the owner and group id of the named file or directory to the specified values. If uid or gid are -1, the value in question will remain unchanged.
Halts with an error message if one occurred.
Arguments: - name : string -- The name of the file to be changed.
- uid : int -- The intended new owner(user) id, or -1 if it should remain the same.
- gid : int -- The intended new group owner(id), or -1 if it should remain the same.
-
proc
copy
(src: string, dest: string, metadata: bool = false) throws¶ Copies the contents and permissions of the file indicated by src into the file or directory dest. If dest is a directory, will halt with an error message. If metadata is set to true, will also copy the metadata (uid, gid, time of last access and time of modification) of the file to be copied.
May halt with other error messages.
Note
In the future, when the
Path
module has been expanded further, this function will be able to support directories for the dest argument.Arguments: - src : string -- The source file whose contents and permissions are to be copied
- dest : string -- The name of the destination file for the contents and permissions. May or may not exist previously, but will be overwritten if it did exist
- metadata : bool -- This argument indicates whether to copy metadata associated with the source file. It is set to false by default.
-
proc
copyFile
(src: string, dest: string) throws¶ Copies the contents of the file indicated by src into the file indicated by dest, replacing dest's contents if it already exists (and is a different file than src, i.e. not a symbolic link to src).
If dest is not writable, or src and dest refer to the same file, this function will halt with an error message. Does not copy metadata. May halt with other error messages.
Arguments: - src : string -- The source file whose contents are to be copied.
- dest : string -- The intended destination of the contents.
-
proc
copyMode
(src: string, dest: string) throws¶ Copies the permissions of the file indicated by src to the file indicated by dest, leaving contents, owner and group unaffected.
Will halt with an error message if one is detected.
Arguments: - src : string -- The source file whose permissions are to be copied.
- dest : string -- The intended destination of the permissions.
-
proc
copyTree
(src: string, dest: string, copySymbolically: bool = false) throws¶ Will recursively copy the tree which lives under src into dst, including all contents, permissions, and metadata. dst must not previously exist, this function assumes it can create it and any missing parent directories. If copySymbolically is true, symlinks will be copied as symlinks, otherwise their contents and metadata will be copied instead.
Will halt with an error message if one is detected.
Arguments: - src : string -- The root of the source tree to be copied.
- dest : string -- The root of the destination directory under which the contents of src are to be copied (must not exist prior to this function call).
- copySymbolically : bool -- This argument is used to indicate how to handle symlinks in the source directory. It is set to false by default
-
proc
locale.
cwd
(): string throws¶ Obtains and returns the current working directory for this locale.
Will halt with an error message if one was detected.
Warning
Another task on this locale can change the current working directory from underneath this task, so use caution when making use of this method in a parallel environment.
Returns: The current working directory for the locale in question. Return type: string
-
proc
exists
(name: string): bool throws¶ Determines if the file or directory indicated by name exists and returns the result of this check.
Will halt with an error message if one was detected.
Arguments: name : string -- The file or directory whose existence is in question. Returns: true if the provided argument corresponds to an existing file or directory, false otherwise. Also returns false for broken symbolic links. Return type: bool
-
iter
findfiles
(startdir: string = ".", recursive: bool = false, hidden: bool = false): string¶ Finds files from a given start directory and yields their names, similar to simple invocations of the command-line find utility. May be invoked in serial or non-zippered parallel contexts.
Arguments: - startdir : string -- The root directory from which to start the search
(defaults to
"."
) - recursive : bool -- Indicates whether or not to descend recursively into subdirectories (defaults to false)
- hidden : bool -- Indicates whether or not to descend into hidden subdirectories and yield hidden files (defaults to false)
Yields: The paths to any files found, relative to startdir, as strings
- startdir : string -- The root directory from which to start the search
(defaults to
-
proc
getGID
(name: string): int throws¶ Obtains and returns the group id associated with the file or directory specified by name.
Will halt with an error message if one is detected
Arguments: name : string -- The file or directory whose group id is desired Returns: The group id of the file or directory in question Return type: int
-
proc
getMode
(name: string): int throws¶ Obtains and returns the current permissions of the file or directory specified by name.
Will halt with an error message if one is detected
Arguments: name : string -- The file or directory whose permissions are desired. Returns: The permissions of the specified file or directory See description of S_IRUSR
, for instance, for potential values.Return type: int
-
proc
getFileSize
(name: string): int throws¶ Obtains and returns the size (in bytes) of the file specified by name.
Will halt with an error message if one is detected
Arguments: name : string -- The file whose size is desired Returns: The size in bytes of the file in question Return type: int
-
proc
getUID
(name: string): int throws¶ Obtains and returns the user id associated with the file or directory specified by name.
Will halt with an error message if one is detected.
Arguments: name : string -- The file or directory whose user id is desired Returns: The user id of the specified file or directory Return type: int
-
iter
glob
(pattern: string = "*"): string¶ Yields filenames that match a given glob pattern. May be invoked in serial or parallel contexts (zippered or non-).
Arguments: pattern : string -- The glob pattern to match against (defaults to "*"
)Yields: The matching filenames as strings
-
proc
isDir
(name: string): bool throws¶ Determine if the provided path name corresponds to a directory and return the result
Will halt with an error message if one is detected, including if the path does not refer to a valid file or directory
Arguments: name : string -- A path that could refer to a directory. Returns: true if the path is a directory, false if it is not Return type: bool
-
proc
isFile
(name: string): bool throws¶ Determine if the provided path name corresponds to a file and return the result
Will halt with an error message if one is detected, including if the path does not refer to a valid file or directory
Arguments: name : string -- A path that could refer to a file. Returns: true if the path is a file, false if it is not Return type: bool
-
proc
isLink
(name: string): bool throws¶ Determine if the provided path name corresponds to a link and return the result. If symbolic links are not supported, will return false.
Will halt with an error message if one is detected, including if the path does not refer to a valid file or directory
Arguments: name : string -- A path that could refer to a symbolic link. Returns: true if the path is a symbolic link, false if it is not or if symbolic links are not supported. Return type: bool
-
proc
isMount
(name: string): bool throws¶ Determine if the provided path name corresponds to a mount point and return the result.
Will halt with an error message if one is detected, including if the path does not refer to a valid file or directory.
Arguments: name : string -- A path that could refer to a mount point. Returns: true if the path is a mount point, false if it is not. Return type: bool
-
iter
listdir
(path: string = ".", hidden: bool = false, dirs: bool = true, files: bool = true, listlinks: bool = true): string¶ Lists the contents of a directory. May be invoked in serial contexts only.
Arguments: - path : string -- The directory whose contents should be listed
(defaults to
"."
) - hidden : bool -- Indicates whether hidden files/directory should be listed (defaults to false)
- dirs : bool -- Indicates whether directories should be listed (defaults to true)
- files : bool -- Indicates whether files should be listed (defaults to true)
- listlinks : bool -- Indicates whether symbolic links should be listed (defaults to true)
Yields: The names of the specified directory's contents, as strings
- path : string -- The directory whose contents should be listed
(defaults to
-
proc
mkdir
(name: string, mode: int = 511, parents: bool = false) throws¶ Attempt to create a directory with the given path, name. If parents is true, will attempt to create any directory in the path that did not previously exist.
Will halt with an error message if one is detected
Warning
In the case where parents is true, there is a potential security vulnerability. Checking whether parent directories exist and creating them are separate events. This is called a Time of Check, Time of Use vulnerability (TOCTOU), and in the case of files or directories that did not previously exist, there is no known guard against it. So even if parents == true and a parent directory didn't exist before this function was called but does exist afterward, it's not necessarily true that this function created that parent. Some other concurrent operation could have done so, either intentionally or unintentionally, maliciously or ignorantly. This option is provided as a convenience only, and any attempt to perform the same functionality will run a similar risk.
Arguments: - name : string -- The name of the directory to be created, fully specified.
- mode : int -- The permissions desired for the directory to create. Takes the
current
umask
into account. See description ofS_IRUSR
, for instance, for potential values. - parents : bool -- Indicates whether parent directories should be created. If set to false, any nonexistent parent will cause an error to occur.
-
proc
moveDir
(src: string, dest: string) throws¶ Recursively moves the directory indicated by src and its contents to the destination denoted by dest. If dest is a directory, src is moved inside of it.
Note
We do not currently support the case where the dest argument already exists and is a directory. When the
Path
module has been expanded further, this support can be enabled.Will halt with an error message if one is detected.
Arguments: - src : string -- the location of the directory to be moved
- dest : string -- the location to move it to.
-
proc
rename
(oldname: string, newname: string) throws¶ Renames the file specified by oldname to newname. The file is not opened during this operation.
Will halt with an error message if one is detected
Arguments: - oldname : string -- Current name of the file
- newname : string -- Name which should be used to refer to the file in the future.
-
proc
remove
(name: string) throws¶ Removes the file or directory specified by name
Will halt with an error message if one is detected
Arguments: name : string -- The file/directory to remove
-
proc
rmTree
(root: string) throws¶ Delete the entire directory tree specified by root.
Will halt with an error message if one is detected.
Arguments: root : string -- path name representing a directory that should be deleted along with its entire contents.
-
proc
sameFile
(file1: string, file2: string): bool throws¶ Determines if both pathnames refer to the same file or directory (utilizing operating system operations rather than string ones, due to the possibility of symbolic links,
curDir
, orparentDir
appearing in the path) and returns the result of that checkWill halt with an error message if one is detected
Arguments: - file1 : string -- The first path to be compared.
- file2 : string -- The second path to be compared.
Returns: true if the two paths refer to the same file or directory, false otherwise.
Return type: bool
-
proc
sameFile
(file1: file, file2: file): bool throws Determines if both
file
records refer to the same file (utilizing operating system operations rather than string ones, due to the possibility of symbolic links,curDir
, orparentDir
appearing in the path) and returns the result of that checkWill halt with an error message if one is detected
Arguments: - file1 : file -- The first file to be compared.
- file2 : file -- The second file to be compared.
Returns: true if the two records refer to the same file, false otherwise.
Return type: bool
-
proc
symlink
(oldName: string, newName: string) throws¶ Create a symbolic link pointing to oldName with the path newName.
Will halt with an error message if one is detected
Arguments: - oldName : string -- The source file to be linked
- newName : string -- The location where the symbolic link should live
-
proc
locale.
umask
(mask: int): int¶ Sets the file creation mask of the current locale to mask, and returns the previous value of the file creation mask for that locale. See description of
S_IRUSR
, for instance, for potential values.Warning
This is not safe within a parallel context. A umask call in one task will affect the umask of all tasks for that locale.
Arguments: mask : int -- The file creation mask to use now. Returns: The previous file creation mask Return type: int
-
iter
walkdirs
(path: string = ".", topdown: bool = true, depth: int = max(int), hidden: bool = false, followlinks: bool = false, sort: bool = false): string¶ Recursively walk a directory structure, yielding directory names. May be invoked in serial or non-zippered parallel contexts.
Note
The current parallel version is not very adaptive/dynamic in its application of parallelism to the list of subdirectories at any given level of the traversal, and could be improved in this regard.
Arguments: - path : string -- The directory from which to start the walk (defaults to
"."
) - topdown : bool -- Indicates whether to yield a directory before or after descending into its children (defaults to true)
- depth : int -- Indicates the maximum recursion depth to use (defaults to max(int))
- hidden : bool -- Indicates whether to descend into hidden directories (defaults to false)
- followlinks : bool -- Indicates whether to follow symbolic links (defaults to false)
- sort : bool -- Indicates whether or not to consider subdirectories in sorted order (defaults to false). Note that requesting sorting has no effect in parallel invocations.
Yields: The directory names encountered, relative to path, as strings
- path : string -- The directory from which to start the walk (defaults to