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std.file
Utilities for manipulating files and scanning directories. Functions
in this module handle files as a unit, e.g., read or write one file
at a time. For opening files and manipulating them via handles refer
to module std.stdio.
Category | Functions |
---|---|
General | exists isDir isFile isSymlink rename thisExePath |
Directories | chdir dirEntries getcwd mkdir mkdirRecurse rmdir rmdirRecurse tempDir |
Files | append copy read readText remove slurp write |
Symlinks | symlink readLink |
Attributes | attrIsDir attrIsFile attrIsSymlink getAttributes getLinkAttributes getSize setAttributes |
Timestamp | getTimes getTimesWin setTimes timeLastModified timeLastAccessed timeStatusChanged |
Other | DirEntry FileException PreserveAttributes SpanMode getAvailableDiskSpace |
See Also:
The official tutorial for an
introduction to working with files in D, module
std.stdio for opening files and manipulating them via handles,
and module std.path for manipulating path strings.
License:
Authors:
Source std/file.d
- class
FileException
: object.Exception; - Exception thrown for file I/O errors.Examples:
import std.exception : assertThrown; assertThrown!FileException("non.existing.file.".readText);
- immutable uint
errno
; - OS error code.
- pure @safe this(scope const(char)[]
name
, scope const(char)[]msg
, stringfile
= __FILE__, size_tline
= __LINE__); - Constructor which takes an error message.Parameters:
const(char)[] name
Name of file for which the error occurred. const(char)[] msg
Message describing the error. string file
The file where the error occurred. size_t line
The line where the error occurred. - @trusted this(scope const(char)[]
name
, uinterrno
= .errno
, stringfile
= __FILE__, size_tline
= __LINE__); - Constructor which takes the error number (GetLastError in Windows, errno in POSIX).Parameters:
const(char)[] name
Name of file for which the error occurred. uint errno
The error number. string file
The file where the error occurred. Defaults to __FILE__. size_t line
The line where the error occurred. Defaults to __LINE__.
- void[]
read
(R)(Rname
, size_tupTo
= size_t.max)
if (isInputRange!R && isSomeChar!(ElementEncodingType!R) && !isInfinite!R && !isConvertibleToString!R);
void[]read
(R)(auto ref Rname
, size_tupTo
= size_t.max)
if (isConvertibleToString!R); - Read entire contents of file
name
and returns it as an untyped array. If the file size is larger thanupTo
, onlyupTo
bytes are read.Parameters:R name
string or range of characters representing the file name size_t upTo
if present, the maximum number of bytes to read Returns:Untyped array of bytes read.Throws:FileException on error.Examples:import std.utf : byChar; scope(exit) { assert(exists(deleteme)); remove(deleteme); } std.file.write(deleteme, "1234"); // deleteme is the name of a temporary file writeln(read(deleteme, 2)); // "12" writeln(read(deleteme.byChar)); // "1234" writeln((cast(const(ubyte)[])read(deleteme)).length); // 4
- S
readText
(S = string, R)(auto ref Rname
)
if (isSomeString!S && (isInputRange!R && !isInfinite!R && isSomeChar!(ElementType!R) || is(StringTypeOf!R))); - Reads and validates (using std.utf.validate) a text file. S can be an array of any character type. However, no width or endian conversions are performed. So, if the width or endianness of the characters in the given file differ from the width or endianness of the element type of S, then validation will fail.Parameters:
S the string type of the file R name
string or range of characters representing the file name Returns:Array of characters read.Throws:FileException if there is an error reading the file, std.utf.UTFException on UTF decoding error.Examples:Read file with UTF-8 text.write(deleteme, "abc"); // deleteme is the name of a temporary file scope(exit) remove(deleteme); string content = readText(deleteme); writeln(content); // "abc"
- void
write
(R)(Rname
, const void[]buffer
)
if ((isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) || isSomeString!R) && !isConvertibleToString!R);
voidwrite
(R)(auto ref Rname
, const void[]buffer
)
if (isConvertibleToString!R); - Write
buffer
to filename
.Creates the file if it does not already exist.Parameters:R name
string or range of characters representing the file name void[] buffer
data to be written to file Throws:FileException on error.See Also:Examples:scope(exit) { assert(exists(deleteme)); remove(deleteme); } int[] a = [ 0, 1, 1, 2, 3, 5, 8 ]; write(deleteme, a); // deleteme is the name of a temporary file const bytes = read(deleteme); const fileInts = () @trusted { return cast(int[]) bytes; }(); writeln(fileInts); // a
- void
append
(R)(Rname
, const void[]buffer
)
if ((isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) || isSomeString!R) && !isConvertibleToString!R);
voidappend
(R)(auto ref Rname
, const void[]buffer
)
if (isConvertibleToString!R); - Appends
buffer
to filename
.Creates the file if it does not already exist.Parameters:R name
string or range of characters representing the file name void[] buffer
data to be appended to file Throws:FileException on error.Examples:scope(exit) { assert(exists(deleteme)); remove(deleteme); } int[] a = [ 0, 1, 1, 2, 3, 5, 8 ]; write(deleteme, a); // deleteme is the name of a temporary file int[] b = [ 13, 21 ]; append(deleteme, b); const bytes = read(deleteme); const fileInts = () @trusted { return cast(int[]) bytes; }(); writeln(fileInts); // a ~ b
- void
rename
(RF, RT)(RFfrom
, RTto
)
if ((isInputRange!RF && !isInfinite!RF && isSomeChar!(ElementEncodingType!RF) || isSomeString!RF) && !isConvertibleToString!RF && (isInputRange!RT && !isInfinite!RT && isSomeChar!(ElementEncodingType!RT) || isSomeString!RT) && !isConvertibleToString!RT);
voidrename
(RF, RT)(auto ref RFfrom
, auto ref RTto
)
if (isConvertibleToString!RF || isConvertibleToString!RT); - Rename file
from
toto
, moving it between directories if required. If the target file exists, it is overwritten.It is not possible to rename a file across different mount points or drives. On POSIX, the operation is atomic. That means, ifto
already exists there will be no time period during the operation whereto
is missing. See manpage for rename for more details.Parameters:RF from
string or range of characters representing the existing file name RT to
string or range of characters representing the target file name Throws:FileException on error.Examples:auto t1 = deleteme, t2 = deleteme~"2"; scope(exit) foreach (t; [t1, t2]) if (t.exists) t.remove(); t1.write("1"); t1.rename(t2); writeln(t2.readText); // "1" t1.write("2"); t1.rename(t2); writeln(t2.readText); // "2"
- void
remove
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidremove
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Delete file
name
.Parameters:R name
string or range of characters representing the file name Throws:FileException on error.Examples:import std.exception : assertThrown; deleteme.write("Hello"); writeln(deleteme.readText); // "Hello" deleteme.remove; assertThrown!FileException(deleteme.readText);
- ulong
getSize
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
ulonggetSize
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Get size of file
name
in bytes.Parameters:R name
string or range of characters representing the file name Returns:The size of file in bytes.Throws:FileException on error (e.g., file not found).Examples:scope(exit) deleteme.remove; // create a file of size 1 write(deleteme, "a"); writeln(getSize(deleteme)); // 1 // create a file of size 3 write(deleteme, "abc"); writeln(getSize(deleteme)); // 3
- void
getTimes
(R)(Rname
, out SysTimeaccessTime
, out SysTimemodificationTime
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidgetTimes
(R)(auto ref Rname
, out SysTimeaccessTime
, out SysTimemodificationTime
)
if (isConvertibleToString!R); - Get the access and modified times of file or folder
name
.Parameters:R name
File/Folder name to get times for. SysTime accessTime
Time the file/folder was last accessed. SysTime modificationTime
Time the file/folder was last modified. Throws:FileException on error.Examples:import std.datetime : abs, SysTime; scope(exit) deleteme.remove; write(deleteme, "a"); SysTime accessTime, modificationTime; getTimes(deleteme, accessTime, modificationTime); import std.datetime : Clock, seconds; auto currTime = Clock.currTime(); enum leeway = 5.seconds; auto diffAccess = accessTime - currTime; auto diffModification = modificationTime - currTime; assert(abs(diffAccess) <= leeway); assert(abs(diffModification) <= leeway);
- void
getTimesWin
(R)(Rname
, out SysTimefileCreationTime
, out SysTimefileAccessTime
, out SysTimefileModificationTime
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R); - This function is Windows-Only.Get creation/access/modified times of file
name
. This is the same as getTimes except that it also gives you the file creation time - which isn't possible on POSIX systems.Parameters:R name
File name to get times for. SysTime fileCreationTime
Time the file was created. SysTime fileAccessTime
Time the file was last accessed. SysTime fileModificationTime
Time the file was last modified. Throws:FileException on error. - void
setTimes
(R)(Rname
, SysTimeaccessTime
, SysTimemodificationTime
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidsetTimes
(R)(auto ref Rname
, SysTimeaccessTime
, SysTimemodificationTime
)
if (isConvertibleToString!R); - Set access/modified times of file or folder
name
.Parameters:R name
File/Folder name to get times for. SysTime accessTime
Time the file/folder was last accessed. SysTime modificationTime
Time the file/folder was last modified. Throws:FileException on error.Examples:import std.datetime : DateTime, hnsecs, SysTime; scope(exit) deleteme.remove; write(deleteme, "a"); SysTime accessTime = SysTime(DateTime(2010, 10, 4, 0, 0, 30)); SysTime modificationTime = SysTime(DateTime(2018, 10, 4, 0, 0, 30)); setTimes(deleteme, accessTime, modificationTime); SysTime accessTimeResolved, modificationTimeResolved; getTimes(deleteme, accessTimeResolved, modificationTimeResolved); writeln(accessTime); // accessTimeResolved writeln(modificationTime); // modificationTimeResolved
- SysTime
timeLastModified
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
SysTimetimeLastModified
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Returns the time that the given file was last modified.Parameters:
R name
the name of the file to check Returns:Throws:FileException if the given file does not exist.Examples:import std.datetime : abs, DateTime, hnsecs, SysTime; scope(exit) deleteme.remove; import std.datetime : Clock, seconds; auto currTime = Clock.currTime(); enum leeway = 5.seconds; deleteme.write("bb"); assert(abs(deleteme.timeLastModified - currTime) <= leeway);
- SysTime
timeLastModified
(R)(Rname
, SysTimereturnIfMissing
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R)); - Returns the time that the given file was last modified. If the file does not exist, returns
returnIfMissing
.A frequent usage pattern occurs in build automation tools such as make or ant. To check whether file target must be rebuilt from file source (i.e., target is older than source or does not exist), use the comparison below. The code throws a FileException if source does not exist (as it should). On the other hand, the SysTime.min default makes a non-existing target seem infinitely old so the test correctly prompts building it.Parameters:R name
The name of the file to get the modification time for. SysTime returnIfMissing
The time to return if the given file does not exist. Returns:Example
if (source.timeLastModified >= target.timeLastModified(SysTime.min)) { // must (re)build } else { // target is up-to-date }
Examples:import std.datetime : SysTime; writeln("file.does.not.exist".timeLastModified(SysTime.min)); // SysTime.min auto source = deleteme ~ "source"; auto target = deleteme ~ "target"; scope(exit) source.remove, target.remove; source.write("."); assert(target.timeLastModified(SysTime.min) < source.timeLastModified); target.write("."); assert(target.timeLastModified(SysTime.min) >= source.timeLastModified);
- pure nothrow SysTime
timeLastModified
()(auto ref stat_tstatbuf
); - This function is POSIX-Only.Returns the time that the given file was last modified.Parameters:
stat_t statbuf
stat_t retrieved from file. - pure nothrow SysTime
timeLastAccessed
()(auto ref stat_tstatbuf
); - This function is POSIX-Only.Returns the time that the given file was last accessed.Parameters:
stat_t statbuf
stat_t retrieved from file. - pure nothrow SysTime
timeStatusChanged
()(auto ref stat_tstatbuf
); - This function is POSIX-Only.Returns the time that the given file was last changed.Parameters:
stat_t statbuf
stat_t retrieved from file. - bool
exists
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
boolexists
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Determine whether the given file (or directory) exists.Parameters:
R name
string or range of characters representing the file name Returns:true if the file name specified as input existsExamples:auto f = deleteme ~ "does.not.exist"; assert(!f.exists); f.write("hello"); assert(f.exists); f.remove; assert(!f.exists);
- uint
getAttributes
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
uintgetAttributes
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Returns the attributes of the given file.Note that the file attributes on Windows and POSIX systems are completely different. On Windows, they're what is returned by GetFileAttributes, whereas on POSIX systems, they're the st_mode value which is part of the stat struct gotten by calling the stat function. On POSIX systems, if the given file is a symbolic link, then attributes are the attributes of the file pointed to by the symbolic link.Parameters:
R name
The file to get the attributes of. Returns:The attributes of the file as a uint.Throws:FileException on error.Examples:getAttributes with a fileimport std.exception : assertThrown; auto f = deleteme ~ "file"; scope(exit) f.remove; assert(!f.exists); assertThrown!FileException(f.getAttributes); f.write("."); auto attributes = f.getAttributes; assert(!attributes.attrIsDir); assert(attributes.attrIsFile);
Examples:getAttributes with a directoryimport std.exception : assertThrown; auto dir = deleteme ~ "dir"; scope(exit) dir.rmdir; assert(!dir.exists); assertThrown!FileException(dir.getAttributes); dir.mkdir; auto attributes = dir.getAttributes; assert(attributes.attrIsDir); assert(!attributes.attrIsFile);
- uint
getLinkAttributes
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
uintgetLinkAttributes
(R)(auto ref Rname
)
if (isConvertibleToString!R); - If the given file is a symbolic link, then this returns the attributes of the symbolic link itself rather than file that it points to. If the given file is not a symbolic link, then this function returns the same result as getAttributes.On Windows, getLinkAttributes is identical to getAttributes. It exists on Windows so that you don't have to special-case code for Windows when dealing with symbolic links.Parameters:
R name
The file to get the symbolic link attributes of. Returns:the attributesThrows:FileException on error.Examples:import std.exception : assertThrown; auto source = deleteme ~ "source"; auto target = deleteme ~ "target"; assert(!source.exists); assertThrown!FileException(source.getLinkAttributes); // symlinking isn't available on Windows version (Posix) { scope(exit) source.remove, target.remove; target.write("target"); target.symlink(source); writeln(source.readText); // "target" assert(source.isSymlink); assert(source.getLinkAttributes.attrIsSymlink); }
Examples:if the file is no symlink, getLinkAttributes behaves like getAttributesimport std.exception : assertThrown; auto f = deleteme ~ "file"; scope(exit) f.remove; assert(!f.exists); assertThrown!FileException(f.getLinkAttributes); f.write("."); auto attributes = f.getLinkAttributes; assert(!attributes.attrIsDir); assert(attributes.attrIsFile);
Examples:if the file is no symlink, getLinkAttributes behaves like getAttributesimport std.exception : assertThrown; auto dir = deleteme ~ "dir"; scope(exit) dir.rmdir; assert(!dir.exists); assertThrown!FileException(dir.getLinkAttributes); dir.mkdir; auto attributes = dir.getLinkAttributes; assert(attributes.attrIsDir); assert(!attributes.attrIsFile);
- void
setAttributes
(R)(Rname
, uintattributes
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidsetAttributes
(R)(auto ref Rname
, uintattributes
)
if (isConvertibleToString!R); - Set the attributes of the given file.For example, a programmatic equivalent of Unix's chmod +x
name
to make a file executable isname
.setAttributes
(name
.getAttributes | octal!700).Parameters:R name
the file name uint attributes
the attributes to set the file to Throws:FileException if the given file does not exist.Examples:setAttributes with a fileimport std.exception : assertThrown; import std.conv : octal; auto f = deleteme ~ "file"; version (Posix) { scope(exit) f.remove; assert(!f.exists); assertThrown!FileException(f.setAttributes(octal!777)); f.write("."); auto attributes = f.getAttributes; assert(!attributes.attrIsDir); assert(attributes.attrIsFile); f.setAttributes(octal!777); attributes = f.getAttributes; writeln((attributes & 1023)); // octal!777 }
Examples:setAttributes with a directoryimport std.exception : assertThrown; import std.conv : octal; auto dir = deleteme ~ "dir"; version (Posix) { scope(exit) dir.rmdir; assert(!dir.exists); assertThrown!FileException(dir.setAttributes(octal!777)); dir.mkdir; auto attributes = dir.getAttributes; assert(attributes.attrIsDir); assert(!attributes.attrIsFile); dir.setAttributes(octal!777); attributes = dir.getAttributes; writeln((attributes & 1023)); // octal!777 }
- @property bool
isDir
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
@property boolisDir
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Returns whether the given file is a directory.Parameters:
R name
The path to the file. Returns:true if name specifies a directoryThrows:FileException if the given file does not exist.Examples:import std.exception : assertThrown; auto dir = deleteme ~ "dir"; auto f = deleteme ~ "f"; scope(exit) dir.rmdir, f.remove; assert(!dir.exists); assertThrown!FileException(dir.isDir); dir.mkdir; assert(dir.isDir); f.write("."); assert(!f.isDir);
- pure nothrow @nogc @safe bool
attrIsDir
(uintattributes
); - Returns whether the given file attributes are for a directory.Parameters:
uint attributes
The file attributes. Returns:true if attributes specifies a directoryExamples:import std.exception : assertThrown; auto dir = deleteme ~ "dir"; auto f = deleteme ~ "f"; scope(exit) dir.rmdir, f.remove; assert(!dir.exists); assertThrown!FileException(dir.getAttributes.attrIsDir); dir.mkdir; assert(dir.isDir); assert(dir.getAttributes.attrIsDir); f.write("."); assert(!f.isDir); assert(!f.getAttributes.attrIsDir);
- @property bool
isFile
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
@property boolisFile
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Returns whether the given file (or directory) is a file.On Windows, if a file is not a directory, then it's a file. So, either
isFile
or isDir will return true for any given file. On POSIX systems, ifisFile
is true, that indicates that the file is a regular file (e.g. not a block not device). So, on POSIX systems, it's possible for bothisFile
and isDir to be false for a particular file (in which case, it's a special file). You can use getAttributes to get the attributes to figure out what type of special it is, or you can use DirEntry to get at its statBuf, which is the result from stat. In either case, see the man page for stat for more information.Parameters:R name
The path to the file. Returns:true if name specifies a fileThrows:FileException if the given file does not exist.Examples:import std.exception : assertThrown; auto dir = deleteme ~ "dir"; auto f = deleteme ~ "f"; scope(exit) dir.rmdir, f.remove; dir.mkdir; assert(!dir.isFile); assert(!f.exists); assertThrown!FileException(f.isFile); f.write("."); assert(f.isFile);
- pure nothrow @nogc @safe bool
attrIsFile
(uintattributes
); - Returns whether the given file attributes are for a file.On Windows, if a file is not a directory, it's a file. So, either
attrIsFile
or attrIsDir will return true for the attributes of any given file. On POSIX systems, ifattrIsFile
is true, that indicates that the file is a regular file (e.g. not a block not device). So, on POSIX systems, it's possible for bothattrIsFile
and attrIsDir to be false for a particular file (in which case, it's a special file). If a file is a special file, you can use the attributes to check what type of special file it is (see the man page for stat for more information).Parameters:uint attributes
The file attributes. Returns:true if the given file attributes are for a fileExample
assert(attrIsFile(getAttributes("/etc/fonts/fonts.conf"))); assert(attrIsFile(getLinkAttributes("/etc/fonts/fonts.conf")));
Examples:import std.exception : assertThrown; auto dir = deleteme ~ "dir"; auto f = deleteme ~ "f"; scope(exit) dir.rmdir, f.remove; dir.mkdir; assert(!dir.isFile); assert(!dir.getAttributes.attrIsFile); assert(!f.exists); assertThrown!FileException(f.getAttributes.attrIsFile); f.write("."); assert(f.isFile); assert(f.getAttributes.attrIsFile);
- @property bool
isSymlink
(R)(Rname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
@property boolisSymlink
(R)(auto ref Rname
)
if (isConvertibleToString!R); - Returns whether the given file is a symbolic link.On Windows, returns true when the file is either a symbolic link or a junction point.Parameters:
R name
The path to the file. Returns:true if name is a symbolic linkThrows:FileException if the given file does not exist.Examples:import std.exception : assertThrown; auto source = deleteme ~ "source"; auto target = deleteme ~ "target"; assert(!source.exists); assertThrown!FileException(source.isSymlink); // symlinking isn't available on Windows version (Posix) { scope(exit) source.remove, target.remove; target.write("target"); target.symlink(source); writeln(source.readText); // "target" assert(source.isSymlink); assert(source.getLinkAttributes.attrIsSymlink); }
- pure nothrow @nogc @safe bool
attrIsSymlink
(uintattributes
); - Returns whether the given file attributes are for a symbolic link.On Windows, return true when the file is either a symbolic link or a junction point.Parameters:
uint attributes
The file attributes. Returns:true if attributes are for a symbolic linkExample
core.sys.posix.unistd.symlink("/etc/fonts/fonts.conf", "/tmp/alink"); assert(!getAttributes("/tmp/alink").isSymlink); assert(getLinkAttributes("/tmp/alink").isSymlink);
Examples:import std.exception : assertThrown; auto source = deleteme ~ "source"; auto target = deleteme ~ "target"; assert(!source.exists); assertThrown!FileException(source.getLinkAttributes.attrIsSymlink); // symlinking isn't available on Windows version (Posix) { scope(exit) source.remove, target.remove; target.write("target"); target.symlink(source); writeln(source.readText); // "target" assert(source.isSymlink); assert(source.getLinkAttributes.attrIsSymlink); }
- void
chdir
(R)(Rpathname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidchdir
(R)(auto ref Rpathname
)
if (isConvertibleToString!R); - Change directory to
pathname
. Equivalent to cd on Windows and POSIX.Parameters:R pathname
the directory to step into Throws:FileException on error.Examples:import std.algorithm.comparison : equal; import std.path : buildPath; auto cwd = getcwd; auto dir = deleteme ~ "dir"; dir.mkdir; scope(exit) cwd.chdir, dir.rmdirRecurse; dir.buildPath("a").write("."); dir.chdir; // step into dir "b".write("."); dirEntries(".", SpanMode.shallow).equal( [".".buildPath("b"), ".".buildPath("a")] );
- void
mkdir
(R)(Rpathname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidmkdir
(R)(auto ref Rpathname
)
if (isConvertibleToString!R); - Make a new directory
pathname
.Parameters:R pathname
the path of the directory to make Throws:FileException on POSIX or WindowsException on Windows if an error occured.Examples:import std.file : mkdir; auto dir = deleteme ~ "dir"; scope(exit) dir.rmdir; dir.mkdir; assert(dir.exists);
Examples:import std.exception : assertThrown; assertThrown("a/b/c/d/e".mkdir);
- @safe void
mkdirRecurse
(scope const(char)[]pathname
); - Make directory and all parent directories as needed.Does nothing if the directory specified by
pathname
already exists.Parameters:const(char)[] pathname
the full path of the directory to create Throws:FileException on error.Examples:import std.path : buildPath; auto dir = deleteme ~ "dir"; scope(exit) dir.rmdirRecurse; dir.mkdir; assert(dir.exists); dir.mkdirRecurse; // does nothing // creates all parent directories as needed auto nested = dir.buildPath("a", "b", "c"); nested.mkdirRecurse; assert(nested.exists);
Examples:import std.exception : assertThrown; scope(exit) deleteme.remove; deleteme.write("a"); // cannot make directory as it's already a file assertThrown!FileException(deleteme.mkdirRecurse);
- void
rmdir
(R)(Rpathname
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) && !isConvertibleToString!R);
voidrmdir
(R)(auto ref Rpathname
)
if (isConvertibleToString!R); - Remove directory
pathname
.Parameters:R pathname
Range or string specifying the directory name Throws:FileException on error.Examples:auto dir = deleteme ~ "dir"; dir.mkdir; assert(dir.exists); dir.rmdir; assert(!dir.exists);
- void
symlink
(RO, RL)(ROoriginal
, RLlink
)
if ((isInputRange!RO && !isInfinite!RO && isSomeChar!(ElementEncodingType!RO) || isConvertibleToString!RO) && (isInputRange!RL && !isInfinite!RL && isSomeChar!(ElementEncodingType!RL) || isConvertibleToString!RL)); - This function is POSIX-Only.Creates a symbolic link (symlink).Parameters:
RO original
The file that is being linked. This is the target path that's stored in the symlink. A relative path is relative to the created symlink. RL link
The symlink to create. A relative path is relative to the current working directory. Throws:FileException on error (which includes if the symlink already exists). - string
readLink
(R)(Rlink
)
if (isInputRange!R && !isInfinite!R && isSomeChar!(ElementEncodingType!R) || isConvertibleToString!R); - This function is POSIX-Only.Returns the path to the file pointed to by a symlink. Note that the path could be either relative or absolute depending on the symlink. If the path is relative, it's relative to the symlink, not the current working directory.Throws:FileException on error.
- @trusted string
getcwd
(); - Get the current working directory.Throws:FileException on error.Examples:
auto s = getcwd(); assert(s.length);
- @trusted string
thisExePath
(); - Returns the full path of the current executable.Returns:The path of the executable as a string.Throws:Examples:
import std.path : isAbsolute; auto path = thisExePath(); assert(path.exists); assert(path.isAbsolute); assert(path.isFile);
- struct
DirEntry
; - Info on a file, similar to what you'd get from stat on a POSIX system.
- @safe this(string
path
); - Constructs a DirEntry for the given file (or directory).Parameters:
string path
The file (or directory) to get a DirEntry for. Throws:FileException if the file does not exist. - const @property @safe string
name
(); - Returns the path to the file represented by this DirEntry.
Example
auto de1 = DirEntry("/etc/fonts/fonts.conf"); assert(de1.name == "/etc/fonts/fonts.conf"); auto de2 = DirEntry("/usr/share/include"); assert(de2.name == "/usr/share/include");
- @property @safe bool
isDir
(); - Returns whether the file represented by this DirEntry is a directory.
Example
auto de1 = DirEntry("/etc/fonts/fonts.conf"); assert(!de1.isDir); auto de2 = DirEntry("/usr/share/include"); assert(de2.isDir);
- @property @safe bool
isFile
(); - Returns whether the file represented by this DirEntry is a file.On Windows, if a file is not a directory, then it's a file. So, either
isFile
or isDir will return true. On POSIX systems, ifisFile
is true, that indicates that the file is a regular file (e.g. not a block not device). So, on POSIX systems, it's possible for bothisFile
and isDir to be false for a particular file (in which case, it's a special file). You can use attributes or statBuf to get more information about a special file (see the stat man page for more details).Example
auto de1 = DirEntry("/etc/fonts/fonts.conf"); assert(de1.isFile); auto de2 = DirEntry("/usr/share/include"); assert(!de2.isFile);
- @property @safe bool
isSymlink
(); - Returns whether the file represented by this DirEntry is a symbolic link.On Windows, return true when the file is either a symbolic link or a junction point.
- @property @safe ulong
size
(); - Returns the size of the the file represented by this DirEntry in bytes.
- const @property @safe SysTime
timeCreated
(); - This function is Windows-Only.Returns the creation time of the file represented by this DirEntry.
- @property @safe SysTime
timeLastAccessed
(); - Returns the time that the file represented by this DirEntry was last accessed.Note that many file systems do not update the access time for files (generally for performance reasons), so there's a good chance that
timeLastAccessed
will return the same value as timeLastModified. - @property @safe SysTime
timeLastModified
(); - Returns the time that the file represented by this DirEntry was last modified.
- const @property @safe SysTime
timeStatusChanged
(); - This function is POSIX-Only.Returns the time that the file represented by this DirEntry was last changed (not only in contents, but also in permissions or ownership).
- @property @safe uint
attributes
(); - Returns the attributes of the file represented by this DirEntry.Note that the file attributes on Windows and POSIX systems are completely different. On, Windows, they're what is returned by GetFileAttributes GetFileAttributes Whereas, an POSIX systems, they're the st_mode value which is part of the stat struct gotten by calling stat. On POSIX systems, if the file represented by this DirEntry is a symbolic link, then attributes are the attributes of the file pointed to by the symbolic link.
- @property @safe uint
linkAttributes
(); - On POSIX systems, if the file represented by this DirEntry is a symbolic link, then
linkAttributes
are the attributes of the symbolic link itself. Otherwise,linkAttributes
is identical to attributes.On Windows,linkAttributes
is identical to attributes. It exists on Windows so that you don't have to special-case code for Windows when dealing with symbolic links. - @property @safe stat_t
statBuf
(); - This function is POSIX-Only.The stat struct gotten from calling stat.
- PreserveAttributes
preserveAttributesDefault
; - Defaults to Yes.preserveAttributes on Windows, and the opposite on all other platforms.
- void
copy
(RF, RT)(RFfrom
, RTto
, PreserveAttributespreserve
= preserveAttributesDefault)
if (isInputRange!RF && !isInfinite!RF && isSomeChar!(ElementEncodingType!RF) && !isConvertibleToString!RF && isInputRange!RT && !isInfinite!RT && isSomeChar!(ElementEncodingType!RT) && !isConvertibleToString!RT);
voidcopy
(RF, RT)(auto ref RFfrom
, auto ref RTto
, PreserveAttributespreserve
= preserveAttributesDefault)
if (isConvertibleToString!RF || isConvertibleToString!RT); - Copy file
from
to fileto
. File timestamps are preserved. File attributes are preserved, ifpreserve
equals Yes.preserveAttributes. On Windows only Yes.preserveAttributes (the default on Windows) is supported. If the target file exists, it is overwritten.Parameters:RF from
string or range of characters representing the existing file name RT to
string or range of characters representing the target file name PreserveAttributes preserve
whether to preserve the file attributes Throws:FileException on error.Examples:auto source = deleteme ~ "source"; auto target = deleteme ~ "target"; auto targetNonExistent = deleteme ~ "target2"; scope(exit) source.remove, target.remove, targetNonExistent.remove; source.write("source"); target.write("target"); writeln(target.readText); // "target" source.copy(target); writeln(target.readText); // "source" source.copy(targetNonExistent); writeln(targetNonExistent.readText); // "source"
- @safe void
rmdirRecurse
(scope const(char)[]pathname
);
@safe voidrmdirRecurse
(ref DirEntryde
);
@safe voidrmdirRecurse
(DirEntryde
); - Remove directory and all of its content and subdirectories, recursively.Parameters:
const(char)[] pathname
the path of the directory to completely remove DirEntry de
The DirEntry to remove Throws:FileException if there is an error (including if the given file is not a directory).Examples:import std.path : buildPath; auto dir = deleteme.buildPath("a", "b", "c"); dir.mkdirRecurse; assert(dir.exists); deleteme.rmdirRecurse; assert(!dir.exists); assert(!deleteme.exists);
- enum
SpanMode
: int; - Dictates directory spanning policy for dirEntries (see below).Examples:
import std.algorithm.comparison : equal; import std.algorithm.iteration : map; import std.path : buildPath, relativePath; auto root = deleteme ~ "root"; scope(exit) root.rmdirRecurse; root.mkdir; root.buildPath("animals").mkdir; root.buildPath("animals", "cat").mkdir; root.buildPath("animals", "dog").mkdir; root.buildPath("plants").mkdir; alias removeRoot = (e) => e.relativePath(root); root.dirEntries(SpanMode.shallow).map!removeRoot.equal( ["plants", "animals"]); root.dirEntries(SpanMode.depth).map!removeRoot.equal( ["plants", "animals/dog", "animals/cat", "animals"]); root.dirEntries(SpanMode.breadth).map!removeRoot.equal( ["plants", "animals", "animals/dog", "animals/cat"]);
shallow
- Only spans one directory.
depth
- Spans the directory in depth-first post-order, i.e. the content of any subdirectory is spanned before that subdirectory itself. Useful e.g. when recursively deleting files.
breadth
- Spans the directory in depth-first pre-order, i.e. the content of any subdirectory is spanned right after that subdirectory itself.Note that SpanMode.
breadth
will not result in all directory members occurring before any subdirectory members, i.e. it is not true breadth-first traversal.
- auto
dirEntries
(stringpath
, SpanModemode
, boolfollowSymlink
= true);
autodirEntries
(stringpath
, stringpattern
, SpanModemode
, boolfollowSymlink
= true); - Returns an input range of DirEntry that lazily iterates a given directory, also provides two ways of foreach iteration. The iteration variable can be of type string if only the name is needed, or DirEntry if additional details are needed. The span mode dictates how the directory is traversed. The name of each iterated directory entry contains the absolute or relative path (depending on pathname).Parameters:
string path
The directory to iterate over. If empty, the current directory will be iterated. string pattern
Optional string with wildcards, such as "*.d". When present, it is used to filter the results by their file name. The supported wildcard strings are described under std.path.globMatch. SpanMode mode
Whether the directory's sub-directories should be iterated in depth-first post-order (depth), depth-first pre-order (breadth), or not at all (shallow). bool followSymlink
Whether symbolic links which point to directories should be treated as directories and their contents iterated over. Returns:An input range of DirEntry.Throws:FileException if the directory does not exist.Example
// Iterate a directory in depth foreach (string name; dirEntries("destroy/me", SpanMode.depth)) { remove(name); } // Iterate the current directory in breadth foreach (string name; dirEntries("", SpanMode.breadth)) { writeln(name); } // Iterate a directory and get detailed info about it foreach (DirEntry e; dirEntries("dmd-testing", SpanMode.breadth)) { writeln(e.name, "\t", e.size); } // Iterate over all *.d files in current directory and all its subdirectories auto dFiles = dirEntries("", SpanMode.depth).filter!(f => f.name.endsWith(".d")); foreach (d; dFiles) writeln(d.name); // Hook it up with std.parallelism to compile them all in parallel: foreach (d; parallel(dFiles, 1)) //passes by 1 file to each thread { string cmd = "dmd -c " ~ d.name; writeln(cmd); std.process.executeShell(cmd); } // Iterate over all D source files in current directory and all its // subdirectories auto dFiles = dirEntries("","*.{d,di}",SpanMode.depth); foreach (d; dFiles) writeln(d.name);
Examples:Duplicate functionality of D1's std.file.listdir():string[] listdir(string pathname) { import std.algorithm; import std.array; import std.file; import std.path; return std.file.dirEntries(pathname, SpanMode.shallow) .filter!(a => a.isFile) .map!(a => std.path.baseName(a.name)) .array; } void main(string[] args) { import std.stdio; string[] files = listdir(args[1]); writefln("%s", files); }
- Select!(Types.length == 1, Types[0][], Tuple!Types[])
slurp
(Types...)(stringfilename
, scope const(char)[]format
); - Reads a file line by line and parses the line into a single value or a std.typecons.Tuple of values depending on the length of Types. The lines are parsed using the specified format string. The format string is passed to std.format.formattedRead, and therefore must conform to the format string specification outlined in std.format.Parameters:
Types the types that each of the elements in the line should be returned as string filename
the name of the file to read const(char)[] format
the format string to use when reading Returns:If only one type is passed, then an array of that type. Otherwise, an array of std.typecons.Tuples.Throws:Exception if the format string is malformed. Also, throws Exception if any of the lines in the file are not fully consumed by the call to std.format.formattedRead. Meaning that no empty lines or lines with extra characters are allowed.Examples:import std.typecons : tuple; scope(exit) { assert(exists(deleteme)); remove(deleteme); } write(deleteme, "12 12.25\n345 1.125"); // deleteme is the name of a temporary file // Load file; each line is an int followed by comma, whitespace and a // double. auto a = slurp!(int, double)(deleteme, "%s %s"); writeln(a.length); // 2 writeln(a[0]); // tuple(12, 12.25) writeln(a[1]); // tuple(345, 1.125)
- @trusted string
tempDir
(); - Returns the path to a directory for temporary files.The return value of the function is cached, so the procedures described below will only be performed the first time the function is called. All subsequent runs will return the same string, regardless of whether environment variables and directory structures have changed in the meantime. The POSIX
tempDir
algorithm is inspired by Python's tempfile.tempdir.Returns:On Windows, this function returns the result of calling the Windows API function GetTempPath. On POSIX platforms, it searches through the following list of directories and returns the first one which is found to exist:- The directory given by the TMPDIR environment variable.
- The directory given by the TEMP environment variable.
- The directory given by the TMP environment variable.
- /tmp
- /var/tmp
- /usr/tmp
tempDir
returns "." on failure, representing the current working directory.Examples:import std.ascii : letters; import std.conv : to; import std.path : buildPath; import std.random : randomSample; import std.utf : byCodeUnit; // random id with 20 letters auto id = letters.byCodeUnit.randomSample(20).to!string; auto myFile = tempDir.buildPath(id ~ "my_tmp_file"); scope(exit) myFile.remove; myFile.write("hello"); writeln(myFile.readText); // "hello"
- @safe ulong
getAvailableDiskSpace
(scope const(char)[]path
); - Returns the available disk space based on a given path. On Windows,
path
must be a directory; on POSIX systems, it can be a file or directory.Parameters:const(char)[] path
on Windows, it must be a directory; on POSIX it can be a file or directory Returns:Available space in bytesThrows:FileException in case of failureExamples:import std.exception : assertThrown; auto space = getAvailableDiskSpace("."); assert(space > 0); assertThrown!FileException(getAvailableDiskSpace("ThisFileDoesNotExist123123"));
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