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Files and folders

The functions to read and write files, build paths, list and walk directories, grouped by what you want to do. The From column says what a program needs before it can call one:

built-in: nothing; it is always available.
std/config: #import "std/config", then using config to call it by its bare name.
std/fs: #import "std/fs", then using fs to call it by its bare name.

Jump to: Read or write a whole file · Check that a file or folder exists · Build and take apart paths · Clean up, compare and resolve paths · List and walk folders · Copy, move and delete files · Create, copy and remove folders · Find standard folders and make temporary files · FileInfo: size, kind, times and flags · File numbers: open and close files · File numbers: read, write and seek · Read and write text a line at a time · File: open a file and work in place · Read and write fixed-size records · Streams: read and write bytes · Find files by pattern · Control a folder walk · FsError: find out why a call failed · Links, permissions and file identity · Disk space and volumes · Lock, map and watch files · Open devices, pipes and the console · Read and write settings files: TOML and INI

Read or write a whole file

Function	What it does	From
ReadAllText	Reads a whole file as UTF-8 text into a string, or fails if it cannot be read.	`std/fs`
ReadAllLines	Reads a file's lines into an Array, without their line endings; returns the count.	`std/fs`
ReadAllBytes	Reads a whole file into an Array of bytes; returns the number read.	`std/fs`
WriteAllText	Writes a string to a file as UTF-8, creating the file or replacing it.	`std/fs`
WriteAllBytes	Writes an Array of bytes to a file, creating the file or replacing it.	`std/fs`
AppendAllText	Adds text to the end of a file, creating the file if it is not there.	`std/fs`
AppendAllBytes	Adds an Array of bytes to the end of a file, creating the file if it is not there.	`std/fs`
WriteAtomic	Replaces a file so a reader sees the old or the new contents, never a half-written file.	`std/fs`

Check that a file or folder exists

Function	What it does	From
Exists	Returns true if a file or folder is there; false also when access is denied.	`std/fs`
IsFile	Returns true if the path is a file, following links; false if it cannot tell.	`std/fs`
IsDir	Returns true if the path is a folder, following links; false if it cannot tell.	`std/fs`
IsLink	Returns true if the path itself is a symbolic link.	`std/fs`
TryExists	Returns whether a path exists, or fails when it cannot tell, as when access is denied.	`std/fs`

Build and take apart paths

Function	What it does	From
PathJoin	Joins two to four path parts with one separator; an absolute part drops those before it.	`std/fs`
PathParent	Returns the path without its last part, or an empty string for a root.	`std/fs`
PathFileName	Returns the last part of a path, the file name, or an empty string for a root.	`std/fs`
PathStem	Returns the file name without its extension; a dotfile such as .gitignore keeps its name.	`std/fs`
PathExtension	Returns the extension with its dot, such as .tiko, or an empty string if there is none.	`std/fs`
PathFilePrefix	Returns the file name up to its first dot, so a.tar.gz gives a.	`std/fs`
PathHasExtension	Returns true if the file name has an extension; a dotfile has none.	`std/fs`
PathChangeExtension	Replaces a path's extension, or removes it when the new one is empty.	`std/fs`
PathAddExtension	Adds an extension after any already there, so a.tar becomes a.tar.gz.	`std/fs`
PathSplit	Splits a normalised path into its parts, without the root, in an Array; returns the count.	`std/fs`
PathComponents	Returns the parts of a path as written, drive and root included, for a for each loop.	`std/fs`
PathComponent	Holds one part of a path: its kind, such as root or parent, and its text.	`std/fs`
PathNextComponent	Finds the next part of a path from an offset; returns a negative number when none is left.	`std/fs`
PathRoot	Returns the root of a path, such as C:\ or /, or an empty string for a relative path.	`std/fs`
PathRootLen	Returns the length of a path's root, in characters.	`std/fs`
PathSeparator	Returns the platform's path separator: a backslash on Windows, a slash on Linux and macOS.	`std/fs`

Clean up, compare and resolve paths

Function	What it does	From
PathNormalize	Returns a tidied path: . removed, .. resolved as text, duplicate separators collapsed.	`std/fs`
PathToNative	Returns the path with the platform's separators, duplicates collapsed, nothing resolved.	`std/fs`
PathRelativeTo	Returns a path relative to a base folder; fails if the two have different roots.	`std/fs`
PathEquals	Returns true if two paths match once normalised; case-insensitive on Windows.	`std/fs`
PathStartsWith	Returns true if a path begins with another, comparing whole parts, not characters.	`std/fs`
PathIsAbsolute	Returns true if a path needs no current folder; C:dev and \dev are not absolute.	`std/fs`
PathIsRoot	Returns true if the whole path is just a root, such as C:\ or /.	`std/fs`
PathIsLocal	Returns true if a relative path stays inside the folder it is joined to.	`std/fs`
PathIsReserved	Returns true if a part of the path is a Windows device name such as CON or NUL.	`std/fs`
PathIsCaseSensitive	Returns true if paths compare case-sensitively here: on Linux and macOS, not Windows.	`std/fs`
AbsolutePath	Returns the full form of a path against the current folder; the path need not exist.	`std/fs`
CanonicalPath	Returns the real path with links resolved; it must exist unless allowMissing is true.	`std/fs`

List and walk folders

Function	What it does	From
ReadDir	Lists the entries of one folder for a for each loop; each entry may be a failure to check.	`std/fs`
WalkDir	Lists every entry under a folder, subfolders included, for a for each loop.	`std/fs`
ListDir	Fills an Array with one folder's entries at once; returns the count.	`std/fs`
DirEntry.Name	Returns the entry's name, without its folder.	`std/fs`
DirEntry.Path	Returns the entry's full path, ready to open.	`std/fs`
DirEntry.Depth	Returns how deep the entry is in a walk, 0 for the children of the folder walked.	`std/fs`
DirEntry.IsFile	Returns true if the entry is a file; a link reports as a link, not as its target.	`std/fs`
DirEntry.IsDirectory	Returns true if the entry is a folder; a link to a folder reports as a link.	`std/fs`
DirEntry.IsSymlink	Returns true if the entry is a symbolic link.	`std/fs`
DirEntry.IsOther	Returns true if the entry is a device, pipe or socket rather than a file, folder or link.	`std/fs`
DirEntry.Info	Returns the entry's FileInfo: free on Windows, one extra system call on Linux and macOS.	`std/fs`

Copy, move and delete files

Function	What it does	From
CopyFile	Copies a file; fails if the destination exists unless overwrite is true.	`std/fs`
MoveFile	Moves or renames a file, even across volumes; refuses an existing destination by default.	`std/fs`
RemoveFile	Deletes a file; fails if it is not there.	`std/fs`
ReplaceFile	Replaces one file with another in a single step, so the target is never missing.	`std/fs`

Create, copy and remove folders

Function	What it does	From
CreateDir	Creates one folder; fails if something is already there.	`std/fs`
CreateDirAll	Creates a folder and any missing parents; succeeds if it already exists.	`std/fs`
RemoveDir	Deletes an empty folder; fails if it still holds anything.	`std/fs`
RemoveDirAll	Deletes a folder and all it holds without following links; returns how many it removed.	`std/fs`
CopyDir	Copies a folder and everything in it; returns how many entries it created.	`std/fs`
CopyOptions.Overwrite	Chooses whether CopyDir replaces files already at the destination; false by default.	`std/fs`
CopyOptions.PreserveTimestamps	Chooses whether CopyDir keeps each file's times; false by default.	`std/fs`
CopyOptions.PreservePermissions	Chooses whether CopyDir keeps permission bits or attributes; false by default.	`std/fs`
CopyOptions.CopySymlinksAsLinks	Chooses whether CopyDir copies a link as a link rather than its target; true by default.	`std/fs`

Find standard folders and make temporary files

Function	What it does	From
TempDir	Returns the system's temporary folder; creates nothing.	`std/fs`
CreateTempFile	Creates a uniquely named temporary file and returns its path; it is not deleted for you.	`std/fs`
CreateTempDir	Creates a uniquely named temporary folder and returns its path; it is not deleted for you.	`std/fs`
HomeDir	Returns the user's home folder, without a trailing separator.	`std/fs`
ConfigDir	Returns the folder for user settings, such as AppData\Roaming or ~/.config.	`std/fs`
DataDir	Returns the folder for user data files, such as AppData\Local or ~/.local/share.	`std/fs`
CacheDir	Returns the folder for files that can be rebuilt, such as AppData\Local or ~/.cache.	`std/fs`
StateDir	Returns the folder for logs, history and recent files, such as ~/.local/state.	`std/fs`
ExecutablePath	Returns the full path of the running program, however it was started.	`std/fs`
ExpandHome	Returns a path with a leading ~ replaced by the user's home folder.	`std/fs`
CurrentDir	Returns the program's current folder.	`std/fs`
SetCurrentDir	Changes the program's current folder, for every thread at once.	`std/fs`

FileInfo: size, kind, times and flags

Function	What it does	From
Stat	Returns a path's FileInfo, following symbolic links; fails if the path is missing.	`std/fs`
LStat	Returns a path's FileInfo without following a symbolic link, so a link describes itself.	`std/fs`
FileInfo.Exists	Returns true if the FileInfo describes something that exists.	`std/fs`
FileInfo.IsFile	Returns true if the path is a regular file.	`std/fs`
FileInfo.IsDirectory	Returns true if the path is a folder.	`std/fs`
FileInfo.IsSymlink	Returns true if the path is a symbolic link; only ever true from LStat.	`std/fs`
FileInfo.IsOther	Returns true if the path is a device, pipe or socket rather than a file, folder or link.	`std/fs`
FileInfo.Size	Returns the size in bytes.	`std/fs`
FileInfo.Modified	Returns the last-write time as a chrono.Instant.	`std/fs`
FileInfo.ModifiedUtc	Returns the last-write time in ticks of 100 ns since 0001-01-01 UTC.	`std/fs`
FileInfo.Created	Returns the creation time as a chrono.Instant; check HasCreated first.	`std/fs`
FileInfo.CreatedUtc	Returns the creation time in ticks, or 0 when HasCreated is false.	`std/fs`
FileInfo.Accessed	Returns the last-access time as a chrono.Instant; often not kept up to date.	`std/fs`
FileInfo.AccessedUtc	Returns the last-access time in ticks, or 0 when HasAccessed is false.	`std/fs`
FileInfo.HasCreated	Returns true if the platform records creation times, so Created means something.	`std/fs`
FileInfo.HasAccessed	Returns true if the platform records access times, so Accessed means something.	`std/fs`
FileInfo.IsReadOnly	Returns true if unwritable: the read-only flag, or no write bit on Linux and macOS.	`std/fs`
FileInfo.IsHidden	Returns true if hidden: the hidden flag on Windows, a leading dot on Linux and macOS.	`std/fs`
FileInfo.NativeAttributes	Returns the raw attribute word: attributes on Windows, mode bits on Linux and macOS.	`std/fs`
NativeAttributes	Returns the raw attribute word: attributes on Windows, mode bits on Linux and macOS.	`std/fs`
FileInfo.HasOwner	Returns true if OwnerUid and OwnerGid are filled in: on Linux and macOS, not on Windows.	`std/fs`
FileInfo.OwnerUid	Returns the owner's user id, or 0 unless HasOwner is true.	`std/fs`
FileInfo.OwnerGid	Returns the owner's group id, or 0 unless HasOwner is true.	`std/fs`

File numbers: open and close files

Function	What it does	From
Open	Opens a file on a file number for reading or writing text, bytes or records.	built-in
FreeFile	Returns an unused file number for Open, or 0 if all 255 are taken.	built-in
Close	Closes one or more file numbers, or every open file when given none.	built-in
Reset	Closes every open file, or resets a redirected standard input or output stream.	built-in
Input (file mode)	Opens a text file for reading with Open; the file must already exist.	built-in
Output	Opens a text file for writing with Open, creating it or emptying it first.	built-in
Append	Opens a text file with Open to add to its end, creating the file if needed.	built-in
Binary	Opens a file with Open for reading and writing bytes at any position.	built-in
Random	Opens a file with Open for reading and writing fixed-size records, 128 bytes by default.	built-in
Access	Limits a Binary or Random file in Open to reading, writing, or both.	built-in
Read (access)	Opens a Binary or Random file for reading only, in an Access clause.	built-in
Write (access)	Opens a Binary or Random file for writing only; an existing file is emptied first.	built-in
Read Write (access)	Opens a Binary or Random file for both reading and writing, the default.	built-in
Encoding	Sets the Unicode encoding of a text file in Open; a file read this way needs a BOM.	built-in

File numbers: read, write and seek

Function	What it does	From
Print #	Writes values as text to an open file; a trailing comma or semicolon skips the line break.	built-in
Write #	Writes values to a file as comma-separated text, strings in quotes, for Input # to read.	built-in
Input #	Reads comma- or line-separated values from a text file into variables.	built-in
Line Input #	Reads one line of a text file into a string, without its line ending.	built-in
Get #	Reads a variable, string or array from a file as bytes, at a position or the current one.	built-in
Put #	Writes a variable, string or array to a file as bytes, at a position or the current one.	built-in
EOF	Returns true when an open file has nothing left to read.	built-in
LOF	Returns the length in bytes of an open file.	built-in
LOC	Returns where the last read or write happened in an open file, counted in records.	built-in
Seek (function)	Returns the 1-based position of the next read or write: bytes, or records for Random.	built-in
Seek (statement)	Sets the 1-based position of the next read or write: bytes, or records for Random.	built-in
Lock	Restricts other programs' access to a record or byte range of an open file.	built-in
Unlock	Removes a restriction that Lock put on a record or byte range.	built-in

Read and write text a line at a time

Function	What it does	From
ReadLines	Reads a file a line at a time in a for each loop, never holding the whole file in memory.	`std/fs`
TextReader	Holds a reader that decodes lines and text from any Stream, in UTF-8 or UTF-16.	`std/fs`
TextReader.ReadLine	Reads the next decoded line into a string; returns false at the end.	`std/fs`
TextReader.ReadToEnd	Appends all the remaining decoded text to a string.	`std/fs`
TextReader.Encoding	Returns the encoding found at the start: utf-8, utf-16le or utf-16be.	`std/fs`
TextErrorMode	Holds what a TextReader does with invalid UTF-8: replace it or fail.	`std/fs`
TextWriter	Holds a writer that sends text to any Stream as UTF-8, with an optional BOM.	`std/fs`
TextWriter.WriteLine	Writes a string followed by the writer's NewLine.	`std/fs`

File: open a file and work in place

Function	What it does	From
File	Holds an open file: a Stream over a handle it owns and closes when it goes out of scope.	`std/fs`
File.Open	Opens a file the way an OpenOptions says: read, write, append, create and more.	`std/fs`
File.OpenRead	Opens an existing file for reading only.	`std/fs`
File.Create	Opens a file for writing, creating it or emptying it first.	`std/fs`
File.CreateNew	Creates a new file for writing; fails if one is already there.	`std/fs`
File.OpenAppend	Opens a file so every write goes to its end, creating it if needed.	`std/fs`
File.OpenTemp	Creates and opens a new, randomly named file in a folder or the temporary folder.	`std/fs`
File.Close	Closes the file and reports any error the close itself raised.	`std/fs`
File.IsOpen	Returns true if the File has a file open.	`std/fs`
File.Path	Returns the path the file was opened with.	`std/fs`
File.ReadAt	Reads up to n bytes at an offset without moving the position.	`std/fs`
File.WriteAt	Writes bytes at an offset without moving the position; refused in append mode.	`std/fs`
File.Size	Returns the open file's current size in bytes.	`std/fs`
File.SetSize	Truncates the file to a size, or extends it with zero bytes.	`std/fs`
File.Sync	Forces the file's data and metadata onto the disk, so a write survives a power cut.	`std/fs`
File.SyncData	Forces the file's data onto the disk; can be cheaper than Sync on Linux.	`std/fs`
File.Stat	Returns the open file's FileInfo, read from the handle even if the file was renamed.	`std/fs`
File.Lock	Locks the whole file, waiting until it is free: exclusive by default, or shared.	`std/fs`
File.TryLock	Locks the whole file if it is free, or fails at once if another holder has it.	`std/fs`
File.Unlock	Releases this handle's lock; succeeds when none is held.	`std/fs`
File.Id	Returns the FileId of the open file, still right after a rename.	`std/fs`
File.NativeHandle	Returns the operating-system handle or descriptor, or -1 when closed.	`std/fs`
OpenOptions	Holds the flags that say how File.Open opens a file: read, write, create, share and more.	`std/fs`
OpenOptionsRead	Returns the OpenOptions for reading a file that must already exist.	`std/fs`
OpenOptionsWrite	Returns the OpenOptions for writing a new file or an existing one emptied.	`std/fs`
OpenOptionsAppend	Returns the OpenOptions for adding to the end of a file, creating it if needed.	`std/fs`

Read and write fixed-size records

Function	What it does	From
RecordFile	Holds a file of fixed-size records of one type, read and written by number.	`std/fs`
RecordFile.Open	Opens a file of records for reading and writing, creating it if it is missing.	`std/fs`
RecordFile.GetRecord	Reads record n into a variable; false when the file has no such record.	`std/fs`
RecordFile.PutRecord	Writes a variable as record n, growing the file when n is past the end.	`std/fs`
RecordFile.Append	Writes a variable after the last record and returns its record number.	`std/fs`
RecordFile.Count	Returns the number of whole records in the file.	`std/fs`
ReadRecord	Reads record n of a type from an open File, counting records from 1.	`std/fs`
WriteRecord	Writes a value as record n of an open File, growing the file if needed.	`std/fs`
RecordCount	Returns the number of whole records of a type in an open File.	`std/fs`

Streams: read and write bytes

Function	What it does	From
Stream	Holds the base type of every byte stream, with read, write, seek and flush.	`std/fs`
Stream.Read	Reads up to n bytes and returns how many; 0 means the end of the data.	`std/fs`
Stream.ReadExact	Reads exactly n bytes, or fails if the data ends first.	`std/fs`
Stream.ReadToEnd	Appends every remaining byte to an Array; returns how many.	`std/fs`
Stream.Write	Writes up to n bytes and returns how many it wrote, which may be fewer.	`std/fs`
Stream.WriteAll	Writes all n bytes, calling Write as often as it takes.	`std/fs`
Stream.WriteBytes	Writes every byte of an Array.	`std/fs`
Stream.WriteUtf8	Writes a string as UTF-8, with no BOM.	`std/fs`
Stream.WriteText	Writes a string in a text encoding, the bytes WriteAllText would write.	`std/fs`
Stream.Seek	Moves the position from the start, the current place or the end; returns the new position.	`std/fs`
Stream.Position	Returns the current position, or fails on a stream that cannot seek.	`std/fs`
Stream.Flush	Passes any buffered bytes on to where they are going.	`std/fs`
Stream.CanRead	Returns true if Read can succeed on this stream.	`std/fs`
Stream.CanWrite	Returns true if Write can succeed on this stream.	`std/fs`
Stream.CanSeek	Returns true if Seek can succeed on this stream.	`std/fs`
SeekOrigin	Holds where Stream.Seek measures from: the start, the current position or the end.	`std/fs`
Copy	Copies a stream from its position to its end into another; returns the byte count.	`std/fs`
MemoryStream	Holds a growable byte buffer in memory that reads, writes and seeks like a file.	`std/fs`
MemoryStream.Length	Returns the number of bytes held, whatever the position.	`std/fs`
MemoryStream.Clear	Empties the stream; its length and position become 0.	`std/fs`
MemoryStream.ToBytes	Copies every byte held into an Array; returns the count.	`std/fs`
MemoryStream.ToUtf8Text	Returns the bytes held decoded as text, the same way ReadAllText decodes a file.	`std/fs`
MemoryStream.ToText	Returns the bytes held decoded in a text encoding, as ReadAllText would read them.	`std/fs`
BufferedReader	Holds a Stream that reads another in large pieces, so many small reads stay fast.	`std/fs`
BufferedReader.ReadByte	Reads the next byte; returns false at the end.	`std/fs`
BufferedReader.ReadLine	Reads the next line as raw bytes in a string, not decoded; returns false at the end.	`std/fs`
BufferedReader.ReadUntil	Appends bytes up to and including a delimiter to an Array; returns the count.	`std/fs`
BufferedReader.Peek	Copies up to n upcoming bytes into an Array without consuming them.	`std/fs`
BufferedWriter	Holds a Stream that gathers small writes and passes them on in large pieces.	`std/fs`

Find files by pattern

Function	What it does	From
Glob	Fills an Array with the paths that match a wildcard pattern; returns the count.	`std/fs`
MatchPattern	Returns true if a string matches a wildcard pattern, without touching the disk.	`std/fs`
GlobRoot	Returns the folder a pattern search starts from: the part before the first wildcard.	`std/fs`
PatternWildcardAt	Returns the offset of a pattern's first wildcard, or -1 if it has none.	`std/fs`
PatternIsRecursive	Returns true if a pattern has a double-star part that searches every subfolder.	`std/fs`

Control a folder walk

Function	What it does	From
WalkOptions.MaxDepth	Limits how deep a walk goes: 1 is the immediate children, 0 (the default) no limit.	`std/fs`
WalkOptions.FollowSymlinks	Chooses whether a walk enters linked folders; false by default, so it cannot loop.	`std/fs`
WalkOptions.YieldDirectories	Chooses whether a walk returns folders as well as files; true by default.	`std/fs`
WalkOptions.IncludeHidden	Chooses whether a walk returns hidden entries; true by default.	`std/fs`
WalkOptions.StopOnError	Chooses whether a walk ends at its first error; false by default, so it carries on.	`std/fs`
WalkOptions.ContentsFirst	Chooses whether a walk returns each folder after its contents; false by default.	`std/fs`
WalkOptions.SortByName	Chooses whether a walk lists each folder in name order; false by default.	`std/fs`
WalkOptions.Filter	Sets a function that decides, entry by entry, what a walk returns and what it enters.	`std/fs`
WalkFilter	Holds the type of a walk filter: a function that says skip, yield, descend or stop.	`std/fs`
WalkDecision	Holds a walk filter's answer: skip, yield, descend into, or stop after an entry.	`std/fs`
WalkIterator.SkipChildren	Skips the contents of the folder a walk has just returned.	`std/fs`
DirIterator	Holds the iterator ReadDir hands out, for stepping through a folder without for each.	`std/fs`
WalkIterator	Holds the iterator WalkDir hands out, for stepping through a walk without for each.	`std/fs`
DirIterator.IsValid	Returns true while the iterator is on an entry.	`std/fs`
DirIterator.MoveNext	Moves the iterator on to the next entry.	`std/fs`
DirIterator.Value	Returns the current entry by reference; the next MoveNext makes it invalid.	`std/fs`

FsError: find out why a call failed

Function	What it does	From
FsError.Code	Returns the portable error code, such as FS_NOT_FOUND, to branch on.	`std/fs`
FsError.Message	Returns a fixed one-line description of the error code.	`std/fs`
FsError.Path	Returns the path the failed call was working on, or an empty string.	`std/fs`
FsError.Path2	Returns the second path of a failed copy, move or link call.	`std/fs`
FsError.OsCode	Returns the operating system's own error number, or 0 if the library raised the error.	`std/fs`
FsError.Operation	Returns the name of the call that failed, for diagnostics only.	`std/fs`

Links, permissions and file identity

Function	What it does	From
CreateSymlink	Creates a symbolic link to a target; on Windows this usually needs privilege.	`std/fs`
CreateHardLink	Gives an existing file a second name on the same volume.	`std/fs`
ReadLink	Returns the target a symbolic link points to, as stored; fails if it is not a link.	`std/fs`
IsLink	Returns true if the path itself is a symbolic link.	`std/fs`
LinkCount	Returns how many hard links, or names, a file has.	`std/fs`
GetFileId	Returns the FileId of a path, which tells whether two paths are the same file.	`std/fs`
SameFile	Returns whether two paths name the same file; fails if either is missing.	`std/fs`
FileId	Holds a volume and file number that are equal for every name of one file.	`std/fs`
SetReadOnly	Sets or clears a file's read-only flag, or its write bits on Linux and macOS.	`std/fs`
SetHidden	Sets or clears a file's hidden flag on Windows; fails as unsupported on Linux and macOS.	`std/fs`
GetPosixMode	Returns a file's permission bits on Linux and macOS; fails as unsupported on Windows.	`std/fs`
SetPosixMode	Sets a file's permission bits on Linux and macOS; fails as unsupported on Windows.	`std/fs`
GetWin32Attributes	Returns a file's raw Windows attribute flags; fails as unsupported on Linux and macOS.	`std/fs`
SetWin32Attributes	Replaces a file's whole Windows attribute word; fails as unsupported on Linux and macOS.	`std/fs`
SetTimes	Sets a file's modified and accessed times; a time of 0 leaves that one alone.	`std/fs`
SetTimesNoFollow	Sets a symbolic link's own times, leaving its target alone.	`std/fs`
Chown	Changes a file's owner and group on Linux and macOS, -1 keeping one; fails on Windows.	`std/fs`
LChown	Changes a symbolic link's own owner and group, on Linux and macOS only.	`std/fs`

Disk space and volumes

Function	What it does	From
GetDiskSpace	Returns the total, free and available bytes of the volume a path is on.	`std/fs`
DiskSpace.TotalBytes	Returns the capacity of the volume in bytes.	`std/fs`
DiskSpace.FreeBytes	Returns the free bytes on the volume, ignoring quotas; the number to report.	`std/fs`
DiskSpace.AvailableBytes	Returns the bytes this user may still write; the number to check before writing.	`std/fs`
GetVolumeInfo	Returns the VolumeInfo of the volume a path is on: its root, label and file system.	`std/fs`
GetVolumes	Fills an Array with a VolumeInfo for each drive or mounted disk; returns the count.	`std/fs`
VolumeInfo.RootPath	Returns where the volume is mounted, such as C:\ or /.	`std/fs`
VolumeInfo.Name	Returns the volume's label, which may be empty and always is on Linux and macOS.	`std/fs`
VolumeInfo.FileSystem	Returns the file system's name, such as NTFS or ext4, or an empty string.	`std/fs`
VolumeInfo.MaxComponentLen	Returns the longest file or folder name the volume allows, not the longest path.	`std/fs`
VolumeInfo.IsReadOnly	Returns true if the whole volume is read-only.	`std/fs`
VolumeInfo.IsCaseSensitive	Returns true if names on this volume are case-sensitive.	`std/fs`
VolumeInfo.SupportsLinks	Returns true if the volume can hold symbolic links; false is certain, true a best guess.	`std/fs`

Lock, map and watch files

Function	What it does	From
FileLock.Acquire	Takes a lock on a file that cooperating programs share, waiting up to a timeout.	`std/fs`
FileLock.Release	Releases the lock; harmless when none is held.	`std/fs`
FileLock.IsHeld	Returns true while this FileLock holds its lock.	`std/fs`
MemoryMappedFile.Open	Maps a file into memory, read-only unless writable is true; an empty file fails.	`std/fs`
MemoryMappedFile.Data	Returns a pointer to the mapped bytes, valid until Close.	`std/fs`
MemoryMappedFile.Size	Returns the size of the mapped file in bytes.	`std/fs`
MemoryMappedFile.Flush	Writes changed mapped bytes to the disk now.	`std/fs`
MemoryMappedFile.IsOpen	Returns true while a file is mapped.	`std/fs`
MemoryMappedFile.Close	Unmaps the file; harmless when nothing is mapped.	`std/fs`
FileWatcher.Start	Starts watching a folder for changes, subfolders too when recursive is true.	`std/fs`
FileWatcher.Poll	Fills an Array with the changes seen since the last call, waiting up to a timeout.	`std/fs`
FileWatcher.Stop	Stops watching; harmless when not watching.	`std/fs`
FileWatcher.IsWatching	Returns true while the watcher is running.	`std/fs`
FsChange.Kind	Returns what happened: created, deleted, modified, renamed, or overflow.	`std/fs`
FsChange.Path	Returns the full path of the entry that changed.	`std/fs`

Open devices, pipes and the console

Function	What it does	From
Open Com	Opens a serial port on a file number, with its speed, parity and other settings.	built-in
Open Cons	Opens standard input or output on a file number, to use like a file.	built-in
Open Err	Opens standard input and standard error on a file number, to use like a file.	built-in
Open Lpt	Opens a printer on a file number, so Print # and Put # send data to it.	built-in
Open Pipe	Runs a shell command and opens its input or output on a file number.	built-in
Open Scrn	Opens the screen on a file number, for reading and writing like a file.	built-in

Read and write settings files: TOML and INI

Function	What it does	From
ParseToml	Parses TOML text into a TomlValue tree whose root is a table, or a ConfigError.	`std/config`
LoadToml	Reads a UTF-8 TOML file into a TomlValue tree, or a ConfigError.	`std/config`
TomlValue	Holds one TOML value or table; look keys up with Get, Find or a dotted Path.	`std/config`
ToTomlText	Returns a TomlValue table as TOML text; comments are not kept.	`std/config`
ParseIni	Parses INI text into an IniFile of sections and keys, or a ConfigError.	`std/config`
LoadIni	Reads an INI file into an IniFile, or a ConfigError.	`std/config`
SaveIni	Writes an IniFile to a file as INI text.	`std/config`
IniFile	Holds an INI file's sections and keys in file order: Get, SetValue, Remove.	`std/config`

Functions Files

Files and folders

Read or write a whole file

Check that a file or folder exists

Build and take apart paths

Clean up, compare and resolve paths

List and walk folders

Copy, move and delete files

Create, copy and remove folders

Find standard folders and make temporary files

FileInfo: size, kind, times and flags

File numbers: open and close files

File numbers: read, write and seek

Read and write text a line at a time

File: open a file and work in place

Read and write fixed-size records

Streams: read and write bytes

Find files by pattern

Control a folder walk

FsError: find out why a call failed

Links, permissions and file identity

Disk space and volumes

Lock, map and watch files

Open devices, pipes and the console

Read and write settings files: TOML and INI

See Also

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