os

const DevNull = "/dev/null"

DevNull is the name of the operating system's “null device.” On Unix-like systems, it is "/dev/null"; on Windows, "NUL".

os/file_unix.go:242

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:41

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:50

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:45

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:40

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:42

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:52

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:46

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:57

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:49

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:48

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:47

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:51

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:44

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:43

const (
	// The single letters are the abbreviations
	// used by the String method's formatting.
	ModeDir        = fs.ModeDir        // d: is a directory
	ModeAppend     = fs.ModeAppend     // a: a...

The defined file mode bits are the most significant bits of the [FileMode]. The nine least-significant bits are the standard Unix rwxrwxrwx permissions. The values of these bits should be considered part of the public API and may be used in wire protocols or disk representations: they must not be changed, although new bits might be added.

os/types.go:55

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:85

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:86

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:87

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:81

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:83

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:88

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:89

const (
	// Exactly one of O_RDONLY, O_WRONLY, or O_RDWR must be specified.
	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
	O_WRONLY int = syscall.O_WRONLY // open the file write-only...

Flags to OpenFile wrapping those of the underlying system. Not all flags may be implemented on a given system.

os/file.go:82

const (
	PathSeparator     = '/' // OS-specific path separator
	PathListSeparator = ':' // OS-specific path list separator
)

os/path_unix.go:11

const (
	PathSeparator     = '/' // OS-specific path separator
	PathListSeparator = ':' // OS-specific path list separator
)

os/path_unix.go:10

const (
	SEEK_SET int = 0 // seek relative to the origin of the file
	SEEK_CUR int = 1 // seek relative to the current offset
	SEEK_END int = 2 // seek relative to the end
)

Seek whence values. Deprecated: Use io.SeekStart, io.SeekCurrent, and io.SeekEnd.

os/file.go:97

const (
	SEEK_SET int = 0 // seek relative to the origin of the file
	SEEK_CUR int = 1 // seek relative to the current offset
	SEEK_END int = 2 // seek relative to the end
)

Seek whence values. Deprecated: Use io.SeekStart, io.SeekCurrent, and io.SeekEnd.

os/file.go:98

const (
	SEEK_SET int = 0 // seek relative to the origin of the file
	SEEK_CUR int = 1 // seek relative to the current offset
	SEEK_END int = 2 // seek relative to the end
)

Seek whence values. Deprecated: Use io.SeekStart, io.SeekCurrent, and io.SeekEnd.

os/file.go:96

var Args []string

Args hold the command-line arguments, starting with the program name.

os/proc.go:16

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:24

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:27

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:22

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:19

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:26

var (
	// ErrProcessDone indicates a [Process] has finished.
	ErrProcessDone = errors.New("os: process already finished")

	// ErrNoHandle indicates a [Process] does not have a handle.
	ErrNoHandle...

os/exec.go:23

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:23

var (
	// ErrInvalid indicates an invalid argument.
	// Methods on File will return this error when the receiver is nil.
	ErrInvalid = fs.ErrInvalid // "invalid argument"

	ErrPermission = fs.ErrPe...

Portable analogs of some common system call errors. Errors returned from this package may be tested against these errors with [errors.Is].

os/error.go:21

var (
	// ErrProcessDone indicates a [Process] has finished.
	ErrProcessDone = errors.New("os: process already finished")

	// ErrNoHandle indicates a [Process] does not have a handle.
	ErrNoHandle...

os/exec.go:19

var (
	Stdin  = NewFile(uintptr(syscall.Stdin), "/dev/stdin")
	Stdout = NewFile(uintptr(syscall.Stdout), "/dev/stdout")
	Stderr = NewFile(uintptr(syscall.Stderr), "/dev/stderr")
)

Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors. Note that the Go runtime writes to standard error for panics and crashes; closing Stderr may cause those messages to go elsewhere, perhaps to a file opened later.

os/file.go:74

var (
	Stdin  = NewFile(uintptr(syscall.Stdin), "/dev/stdin")
	Stdout = NewFile(uintptr(syscall.Stdout), "/dev/stdout")
	Stderr = NewFile(uintptr(syscall.Stderr), "/dev/stderr")
)

Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors. Note that the Go runtime writes to standard error for panics and crashes; closing Stderr may cause those messages to go elsewhere, perhaps to a file opened later.

os/file.go:72

var (
	Stdin  = NewFile(uintptr(syscall.Stdin), "/dev/stdin")
	Stdout = NewFile(uintptr(syscall.Stdout), "/dev/stdout")
	Stderr = NewFile(uintptr(syscall.Stderr), "/dev/stderr")
)

Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors. Note that the Go runtime writes to standard error for panics and crashes; closing Stderr may cause those messages to go elsewhere, perhaps to a file opened later.

os/file.go:73

func Chdir(dir string) error

Chdir changes the current working directory to the named directory. If there is an error, it will be of type [*PathError].

os/file.go:361

func Chmod(name string, mode FileMode) error

Chmod changes the mode of the named file to mode. If the file is a symbolic link, it changes the mode of the link's target. If there is an error, it will be of type [*PathError]. A different subset of the mode bits are used, depending on the operating system. On Unix, the mode's permission bits, [ModeSetuid], [ModeSetgid], and [ModeSticky] are used. On Windows, only the 0o200 bit (owner writable) of mode is used; it controls whether the file's read-only attribute is set or cleared. The oth...

os/file.go:644

func Chown(name string, uid int, gid int) error

Chown changes the numeric uid and gid of the named file. If the file is a symbolic link, it changes the uid and gid of the link's target. A uid or gid of -1 means to not change that value. If there is an error, it will be of type [*PathError]. On Windows or Plan 9, Chown always returns the [syscall.EWINDOWS] or [syscall.EPLAN9] error, wrapped in [*PathError].

os/file_posix.go:105

func Chtimes(name string, atime time.Time, mtime time.Time) error

Chtimes changes the access and modification times of the named file, similar to the Unix utime() or utimes() functions. A zero [time.Time] value will leave the corresponding file time unchanged. The underlying filesystem may truncate or round the values to a less precise time unit. If there is an error, it will be of type [*PathError].

os/file_posix.go:179

func Clearenv()

Clearenv deletes all environment variables.

os/env.go:133

func CopyFS(dir string, fsys fs.FS) error

CopyFS copies the file system fsys into the directory dir, creating dir if necessary. Files are created with mode 0o666 plus any execute permissions from the source, and directories are created with mode 0o777 (before umask). CopyFS will not overwrite existing files. If a file name in fsys already exists in the destination, CopyFS will return an error such that errors.Is(err, fs.ErrExist) will be true. Symbolic links in dir are followed. New files added to fsys (including if dir is a subd...

os/dir.go:145

func Create(name string) (*File, error)

Create creates or truncates the named file. If the file already exists, it is truncated. If the file does not exist, it is created with mode 0o666 (before umask). If successful, methods on the returned File can be used for I/O; the associated file descriptor has mode [O_RDWR]. The directory containing the file must already exist. If there is an error, it will be of type [*PathError].

os/file.go:399

func CreateTemp(dir string, pattern string) (*File, error)

CreateTemp creates a new temporary file in the directory dir, opens the file for reading and writing, and returns the resulting file. The filename is generated by taking pattern and adding a random string to the end. If pattern includes a "*", the random string replaces the last "*". The file is created with mode 0o600 (before umask). If dir is the empty string, CreateTemp uses the default directory for temporary files, as returned by [TempDir]. Multiple programs or goroutines calling CreateT...

os/tempfile.go:35

func DirFS(dir string) fs.FS

DirFS returns a file system (an fs.FS) for the tree of files rooted at the directory dir. Note that DirFS("/prefix") only guarantees that the Open calls it makes to the operating system will begin with "/prefix": DirFS("/prefix").Open("file") is the same as os.Open("/prefix/file"). So if /prefix/file is a symbolic link pointing outside the /prefix tree, then using DirFS does not stop the access any more than using os.Open does. Additionally, the root of the fs.FS returned for a relative path...

os/file.go:743

func Environ() []string

Environ returns a copy of strings representing the environment, in the form "key=value".

os/env.go:139

func Executable() (string, error)

Executable returns the path name for the executable that started the current process. There is no guarantee that the path is still pointing to the correct executable. If a symlink was used to start the process, depending on the operating system, the result might be the symlink or the path it pointed to. If a stable result is needed, [path/filepath.EvalSymlinks] might help. Executable returns an absolute path unless an error occurred. The main use case is finding resources located relative t...

os/executable.go:18

func Exit(code int)

Exit causes the current program to exit with the given status code. Conventionally, code zero indicates success, non-zero an error. The program terminates immediately; deferred functions are not run. For portability, the status code should be in the range [0, 125].

os/proc.go:62

func Expand(s string, mapping func(...)) string

Expand replaces ${var} or $var in the string based on the mapping function. For example, [os.ExpandEnv](s) is equivalent to [os.Expand](s, [os.Getenv]).

os/env.go:16

func ExpandEnv(s string) string

ExpandEnv replaces ${var} or $var in the string according to the values of the current environment variables. References to undefined variables are replaced by the empty string.

os/env.go:50

func FindProcess(pid int) (*Process, error)

FindProcess looks for a running process by its pid. The [Process] it returns can be used to obtain information about the underlying operating system process. On Unix systems, FindProcess always succeeds and returns a Process for the given pid, regardless of whether the process exists. To test whether the process actually exists, see whether p.Signal(syscall.Signal(0)) reports an error.

os/exec.go:253

func Getegid() int

Getegid returns the numeric effective group id of the caller. On Windows, it returns -1.

os/proc.go:46

func Getenv(key string) string

Getenv retrieves the value of the environment variable named by the key. It returns the value, which will be empty if the variable is not present. To distinguish between an empty value and an unset value, use [LookupEnv].

os/env.go:101

func Geteuid() int

Geteuid returns the numeric effective user id of the caller. On Windows, it returns -1.

os/proc.go:36

func Getgid() int

Getgid returns the numeric group id of the caller. On Windows, it returns -1.

os/proc.go:41

func Getgroups() ([]int, error)

Getgroups returns a list of the numeric ids of groups that the caller belongs to. On Windows, it returns [syscall.EWINDOWS]. See the [os/user] package for a possible alternative.

os/proc.go:52

func Getpagesize() int

Getpagesize returns the underlying system's memory page size.

os/types.go:13

func Getpid() int

Getpid returns the process id of the caller.

os/exec.go:239

func Getppid() int

Getppid returns the process id of the caller's parent.

os/exec.go:242

func Getuid() int

Getuid returns the numeric user id of the caller. On Windows, it returns -1.

os/proc.go:31

func Getwd() (string, error)

Getwd returns an absolute path name corresponding to the current directory. If the current directory can be reached via multiple paths (due to symbolic links), Getwd may return any one of them. On Unix platforms, if the environment variable PWD provides an absolute name, and it is a name of the current directory, it is returned.

os/getwd.go:26

func Hostname() (string, error)

Hostname returns the host name reported by the kernel.

os/sys.go:8

func IsExist(err error) bool

IsExist returns a boolean indicating whether its argument is known to report that a file or directory already exists. It is satisfied by [ErrExist] as well as some syscall errors. This function predates [errors.Is]. It only supports errors returned by the os package. New code should use errors.Is(err, fs.ErrExist).

os/error.go:80

func IsNotExist(err error) bool

IsNotExist returns a boolean indicating whether its argument is known to report that a file or directory does not exist. It is satisfied by [ErrNotExist] as well as some syscall errors. This function predates [errors.Is]. It only supports errors returned by the os package. New code should use errors.Is(err, fs.ErrNotExist).

os/error.go:90

func IsPathSeparator(c uint8) bool

IsPathSeparator reports whether c is a directory separator character.

os/path_unix.go:15

func IsPermission(err error) bool

IsPermission returns a boolean indicating whether its argument is known to report that permission is denied. It is satisfied by [ErrPermission] as well as some syscall errors. This function predates [errors.Is]. It only supports errors returned by the os package. New code should use errors.Is(err, fs.ErrPermission).

os/error.go:100

func IsTimeout(err error) bool

IsTimeout returns a boolean indicating whether its argument is known to report that a timeout occurred. This function predates [errors.Is], and the notion of whether an error indicates a timeout can be ambiguous. For example, the Unix error EWOULDBLOCK sometimes indicates a timeout and sometimes does not. New code should use errors.Is with a value appropriate to the call returning the error, such as [os.ErrDeadlineExceeded].

os/error.go:112

func Lchown(name string, uid int, gid int) error

Lchown changes the numeric uid and gid of the named file. If the file is a symbolic link, it changes the uid and gid of the link itself. If there is an error, it will be of type [*PathError]. On Windows, it always returns the [syscall.EWINDOWS] error, wrapped in [*PathError].

os/file_posix.go:121

func Link(oldname string, newname string) error

Link creates newname as a hard link to the oldname file. If there is an error, it will be of type *LinkError.

os/file_unix.go:404

func LookupEnv(key string) (string, bool)

LookupEnv retrieves the value of the environment variable named by the key. If the variable is present in the environment the value (which may be empty) is returned and the boolean is true. Otherwise the returned value will be empty and the boolean will be false.

os/env.go:112

func Lstat(name string) (FileInfo, error)

Lstat returns a [FileInfo] describing the named file. If the file is a symbolic link, the returned FileInfo describes the symbolic link. Lstat makes no attempt to follow the link. If there is an error, it will be of type [*PathError]. On Windows, if the file is a reparse point that is a surrogate for another named entity (such as a symbolic link or mounted folder), the returned FileInfo describes the reparse point, and makes no attempt to resolve it.

os/stat.go:24

func Mkdir(name string, perm FileMode) error

Mkdir creates a new directory with the specified name and permission bits (before umask). If there is an error, it will be of type [*PathError].

os/file.go:327

func MkdirAll(path string, perm FileMode) error

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error. The permission bits perm (before umask) are used for all directories that MkdirAll creates. If path is already a directory, MkdirAll does nothing and returns nil.

os/path.go:19

func MkdirTemp(dir string, pattern string) (string, error)

MkdirTemp creates a new temporary directory in the directory dir and returns the pathname of the new directory. The new directory's name is generated by adding a random string to the end of pattern. If pattern includes a "*", the random string replaces the last "*" instead. The directory is created with mode 0o700 (before umask). If dir is the empty string, MkdirTemp uses the default directory for temporary files, as returned by TempDir. Multiple programs or goroutines calling MkdirTemp simul...

os/tempfile.go:86

func NewFile(fd uintptr, name string) *File

NewFile returns a new [File] with the given file descriptor and name. The returned value will be nil if fd is not a valid file descriptor. NewFile's behavior differs on some platforms: - On Unix, if fd is in non-blocking mode, NewFile will attempt to return a pollable file. - On Windows, if fd is opened for asynchronous I/O (that is, [syscall.FILE_FLAG_OVERLAPPED] has been specified in the [syscall.CreateFile] call), NewFile will attempt to return a pollable file by associating ...

os/file.go:133

func NewSyscallError(syscall string, err error) error

NewSyscallError returns, as an error, a new [SyscallError] with the given system call name and error details. As a convenience, if err is nil, NewSyscallError returns nil.

os/error.go:67

func Open(name string) (*File, error)

Open opens the named file for reading. If successful, methods on the returned file can be used for reading; the associated file descriptor has mode [O_RDONLY]. If there is an error, it will be of type [*PathError].

os/file.go:389

func OpenFile(name string, flag int, perm FileMode) (*File, error)

OpenFile is the generalized open call; most users will use Open or Create instead. It opens the named file with specified flag ([O_RDONLY] etc.). If the file does not exist, and the [O_CREATE] flag is passed, it is created with mode perm (before umask); the containing directory must exist. If successful, methods on the returned File can be used for I/O. If there is an error, it will be of type [*PathError].

os/file.go:410

func OpenInRoot(dir string, name string) (*File, error)

OpenInRoot opens the file name in the directory dir. It is equivalent to OpenRoot(dir) followed by opening the file in the root. OpenInRoot returns an error if any component of the name references a location outside of dir. See [Root] for details and limitations.

os/root.go:25

func OpenRoot(name string) (*Root, error)

OpenRoot opens the named directory. It follows symbolic links in the directory name. If there is an error, it will be of type [*PathError].

os/root.go:82

func Pipe() (*File, *File, error)

Pipe returns a connected pair of Files; reads from r return bytes written to w. It returns the files and an error, if any.

os/pipe_wasm.go:13

func ReadDir(name string) ([]DirEntry, error)

ReadDir reads the named directory, returning all its directory entries sorted by filename. If an error occurs reading the directory, ReadDir returns the entries it was able to read before the error, along with the error.

os/dir.go:114

func ReadFile(name string) ([]byte, error)

ReadFile reads the named file and returns the contents. A successful call returns err == nil, not err == EOF. Because ReadFile reads the whole file, it does not treat an EOF from Read as an error to be reported.

os/file.go:864

func Readlink(name string) (string, error)

Readlink returns the destination of the named symbolic link. If there is an error, it will be of type [*PathError]. If the link destination is relative, Readlink returns the relative path without resolving it to an absolute one.

os/file.go:446

func Remove(name string) error

Remove removes the named file or (empty) directory. If there is an error, it will be of type [*PathError].

os/file_unix.go:357

func RemoveAll(path string) error

RemoveAll removes path and any children it contains. It removes everything it can but returns the first error it encounters. If the path does not exist, RemoveAll returns nil (no error). If there is an error, it will be of type [*PathError].

os/path.go:73

func Rename(oldpath string, newpath string) error

Rename renames (moves) oldpath to newpath. If newpath already exists and is not a directory, Rename replaces it. If newpath already exists and is a directory, Rename returns an error. OS-specific restrictions may apply when oldpath and newpath are in different directories. Even within the same directory, on non-Unix platforms Rename is not an atomic operation. If there is an error, it will be of type *LinkError.

os/file.go:437

func SameFile(fi1 FileInfo, fi2 FileInfo) bool

SameFile reports whether fi1 and fi2 describe the same file. For example, on Unix this means that the device and inode fields of the two underlying structures are identical; on other systems the decision may be based on the path names. SameFile only applies to results returned by this package's [Stat]. It returns false in other cases.

os/types.go:69

func Setenv(key string, value string) error

Setenv sets the value of the environment variable named by the key. It returns an error, if any.

os/env.go:119

func StartProcess(name string, argv []string, attr *ProcAttr) (*Process, error)

StartProcess starts a new process with the program, arguments and attributes specified by name, argv and attr. The argv slice will become [os.Args] in the new process, so it normally starts with the program name. If the calling goroutine has locked the operating system thread with [runtime.LockOSThread] and modified any inheritable OS-level thread state (for example, Linux or Plan 9 name spaces), the new process will inherit the caller's thread state. StartProcess is a low-level interface. ...

os/exec.go:270

func Stat(name string) (FileInfo, error)

Stat returns a [FileInfo] describing the named file. If there is an error, it will be of type [*PathError].

os/stat.go:11

func Symlink(oldname string, newname string) error

Symlink creates newname as a symbolic link to oldname. On Windows, a symlink to a non-existent oldname creates a file symlink; if oldname is later created as a directory the symlink will not work. If there is an error, it will be of type *LinkError.

os/file_unix.go:418

func TempDir() string

TempDir returns the default directory to use for temporary files. On Unix systems, it returns $TMPDIR if non-empty, else /tmp. On Windows, it uses GetTempPath, returning the first non-empty value from %TMP%, %TEMP%, %USERPROFILE%, or the Windows directory. On Plan 9, it returns /tmp. The directory is neither guaranteed to exist nor have accessible permissions.

os/file.go:487

func Truncate(name string, size int64) error

Truncate changes the size of the named file. If the file is a symbolic link, it changes the size of the link's target. If there is an error, it will be of type [*PathError].

os/file_unix.go:345

func Unsetenv(key string) error

Unsetenv unsets a single environment variable.

os/env.go:128

func UserCacheDir() (string, error)

UserCacheDir returns the default root directory to use for user-specific cached data. Users should create their own application-specific subdirectory within this one and use that. On Unix systems, it returns $XDG_CACHE_HOME as specified by https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html if non-empty, else $HOME/.cache. On Darwin, it returns $HOME/Library/Caches. On Windows, it returns %LocalAppData%. On Plan 9, it returns $home/lib/cache. If the location cannot ...

os/file.go:504

func UserConfigDir() (string, error)

UserConfigDir returns the default root directory to use for user-specific configuration data. Users should create their own application-specific subdirectory within this one and use that. On Unix systems, it returns $XDG_CONFIG_HOME as specified by https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html if non-empty, else $HOME/.config. On Darwin, it returns $HOME/Library/Application Support. On Windows, it returns %AppData%. On Plan 9, it returns $home/lib. If the loca...

os/file.go:557

func UserHomeDir() (string, error)

UserHomeDir returns the current user's home directory. On Unix, including macOS, it returns the $HOME environment variable. On Windows, it returns %USERPROFILE%. On Plan 9, it returns the $home environment variable. If the expected variable is not set in the environment, UserHomeDir returns either a platform-specific default value or a non-nil error.

os/file.go:605

func WriteFile(name string, data []byte, perm FileMode) error

WriteFile writes data to the named file, creating it if necessary. If the file does not exist, WriteFile creates it with permissions perm (before umask); otherwise WriteFile truncates it before writing, without changing permissions. Since WriteFile requires multiple system calls to complete, a failure mid-operation can leave the file in a partially written state.

os/file.go:932