os module

binaryninja.os.DirEntry

binaryninja.os.MutableMapping

binaryninja.os.PathLike

Abstract base class for implementing the file system path protocol.

binaryninja.os.error

alias of builtins.OSError

binaryninja.os.stat_result

stat_result: Result from stat, fstat, or lstat.

binaryninja.os.statvfs_result

statvfs_result: Result from statvfs or fstatvfs.

binaryninja.os.terminal_size

A tuple of (columns, lines) for holding terminal window size

binaryninja.os.times_result

times_result: Result from os.times().

binaryninja.os.uname_result

uname_result: Result from os.uname().

binaryninja.os.execl(file, *args)

Execute the executable file with argument list args, replacing the current process.

binaryninja.os.execle(file, *args, env)

Execute the executable file with argument list args and environment env, replacing the current process.

binaryninja.os.execlp(file, *args)

Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process.

binaryninja.os.execlpe(file, *args, env)

Execute the executable file (which is searched for along $PATH) with argument list args and environment env, replacing the current process.

binaryninja.os.execvp(file, args)

Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process.

binaryninja.os.execvpe(file, args, env)

Execute the executable file (which is searched for along $PATH) with argument list args and environment env , replacing the current process.

binaryninja.os.fdopen(fd, *args, **kwargs)

binaryninja.os.fsdecode(filename)

Decode filename (an os.PathLike, bytes, or str) from the filesystem encoding with ‘surrogateescape’ error handler, return str unchanged.

binaryninja.os.fsencode(filename)

Encode filename (an os.PathLike, bytes, or str) to the filesystem encoding with ‘surrogateescape’ error handler, return bytes unchanged.

binaryninja.os.fwalk([top, topdown, …])

Directory tree generator.

binaryninja.os.get_exec_path([env])

Returns the sequence of directories that will be searched for the named executable (similar to a shell) when launching a process.

binaryninja.os.getenv(key[, default])

Get an environment variable, return None if it doesn’t exist.

binaryninja.os.getenvb(key[, default])

Get an environment variable, return None if it doesn’t exist.

binaryninja.os.makedirs(name [[, mode, exist_ok])

Super-mkdir; create a leaf directory and all intermediate ones.

binaryninja.os.popen(cmd[, mode, buffering])

binaryninja.os.removedirs(name)

Super-rmdir; remove a leaf directory and all empty intermediate ones.

binaryninja.os.renames(old, new)

Super-rename; create directories as necessary and delete any left empty.

binaryninja.os.spawnl(mode, file, *args)

Execute file with arguments from args in a subprocess.

binaryninja.os.spawnle(mode, file, *args, env)

Execute file with arguments from args in a subprocess with the supplied environment.

binaryninja.os.spawnlp(mode, file, *args)

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment.

binaryninja.os.spawnlpe(mode, file, *args, env)

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment.

binaryninja.os.spawnv(mode, file, args)

Execute file with arguments from args in a subprocess.

binaryninja.os.spawnve(mode, file, args, env)

Execute file with arguments from args in a subprocess with the specified environment.

binaryninja.os.spawnvp(mode, file, args)

Execute file (which is looked for along $PATH) with arguments from args in a subprocess.

binaryninja.os.spawnvpe(mode, file, args, env)

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment.

binaryninja.os.walk(top[, topdown, onerror, …])

Directory tree generator.

OS routines for NT or Posix depending on what system we’re on.

This exports:
  • all functions from posix or nt, e.g. unlink, stat, etc.

  • os.path is either posixpath or ntpath

  • os.name is either ‘posix’ or ‘nt’

  • os.curdir is a string representing the current directory (always ‘.’)

  • os.pardir is a string representing the parent directory (always ‘..’)

  • os.sep is the (or a most common) pathname separator (‘/’ or ‘')

  • os.extsep is the extension separator (always ‘.’)

  • os.altsep is the alternate pathname separator (None or ‘/’)

  • os.pathsep is the component separator used in $PATH etc

  • os.linesep is the line separator in text files (‘r’ or ‘n’ or ‘rn’)

  • os.defpath is the default search path for executables

  • os.devnull is the file path of the null device (‘/dev/null’, etc.)

Programs that import and use ‘os’ stand a better chance of being portable between different platforms. Of course, they must then only use functions that are defined by all platforms (e.g., unlink and opendir), and leave all pathname manipulation to os.path (e.g., split and join).

error

alias of builtins.OSError

class DirEntry

Bases: object

inode()

Return inode of the entry; cached per entry.

is_dir()

Return True if the entry is a directory; cached per entry.

is_file()

Return True if the entry is a file; cached per entry.

Return True if the entry is a symbolic link; cached per entry.

stat()

Return stat_result object for the entry; cached per entry.

name

the entry’s base filename, relative to scandir() “path” argument

path

the entry’s full path name; equivalent to os.path.join(scandir_path, entry.name)

class stat_result

Bases: tuple

stat_result: Result from stat, fstat, or lstat.

This object may be accessed either as a tuple of

(mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime)

or via the attributes st_mode, st_ino, st_dev, st_nlink, st_uid, and so on.

Posix/windows: If your platform supports st_blksize, st_blocks, st_rdev, or st_flags, they are available as attributes only.

See os.stat for more information.

n_fields = 22
n_sequence_fields = 10
n_unnamed_fields = 3
st_atime

time of last access

st_atime_ns

time of last access in nanoseconds

st_birthtime

time of creation

st_blksize

blocksize for filesystem I/O

st_blocks

number of blocks allocated

st_ctime

time of last change

st_ctime_ns

time of last change in nanoseconds

st_dev

device

st_flags

user defined flags for file

st_gen

generation number

st_gid

group ID of owner

st_ino

inode

st_mode

protection bits

st_mtime

time of last modification

st_mtime_ns

time of last modification in nanoseconds

number of hard links

st_rdev

device type (if inode device)

st_size

total size, in bytes

st_uid

user ID of owner

class statvfs_result

Bases: tuple

statvfs_result: Result from statvfs or fstatvfs.

This object may be accessed either as a tuple of

(bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flag, namemax),

or via the attributes f_bsize, f_frsize, f_blocks, f_bfree, and so on.

See os.statvfs for more information.

f_bavail
f_bfree
f_blocks
f_bsize
f_favail
f_ffree
f_files
f_flag
f_frsize
f_fsid
f_namemax
n_fields = 11
n_sequence_fields = 10
n_unnamed_fields = 0
class terminal_size

Bases: tuple

A tuple of (columns, lines) for holding terminal window size

columns

width of the terminal window in characters

lines

height of the terminal window in characters

n_fields = 2
n_sequence_fields = 2
n_unnamed_fields = 0
class times_result

Bases: tuple

times_result: Result from os.times().

This object may be accessed either as a tuple of

(user, system, children_user, children_system, elapsed),

or via the attributes user, system, children_user, children_system, and elapsed.

See os.times for more information.

children_system

system time of children

children_user

user time of children

elapsed

elapsed time since an arbitrary point in the past

n_fields = 5
n_sequence_fields = 5
n_unnamed_fields = 0
system

system time

user

user time

class uname_result

Bases: tuple

uname_result: Result from os.uname().

This object may be accessed either as a tuple of

(sysname, nodename, release, version, machine),

or via the attributes sysname, nodename, release, version, and machine.

See os.uname for more information.

machine

hardware identifier

n_fields = 5
n_sequence_fields = 5
n_unnamed_fields = 0
nodename

name of machine on network (implementation-defined)

release

operating system release

sysname

operating system name

version

operating system version

fsencode(filename)

Encode filename (an os.PathLike, bytes, or str) to the filesystem encoding with ‘surrogateescape’ error handler, return bytes unchanged. On Windows, use ‘strict’ error handler if the file system encoding is ‘mbcs’ (which is the default encoding).

fsdecode(filename)

Decode filename (an os.PathLike, bytes, or str) from the filesystem encoding with ‘surrogateescape’ error handler, return str unchanged. On Windows, use ‘strict’ error handler if the file system encoding is ‘mbcs’ (which is the default encoding).

get_exec_path(env=None)

Returns the sequence of directories that will be searched for the named executable (similar to a shell) when launching a process.

env must be an environment variable dict or None. If env is None, os.environ will be used.

fdopen(fd, *args, **kwargs)
popen(cmd, mode='r', buffering=-1)
WCOREDUMP()

Return True if the process returning status was dumped to a core file.

WEXITSTATUS()

Return the process return code from status.

WIFCONTINUED()

Return True if a particular process was continued from a job control stop.

Return True if the process returning status was continued from a job control stop.

WIFEXITED()

Return True if the process returning status exited via the exit() system call.

WIFSIGNALED()

Return True if the process returning status was terminated by a signal.

WIFSTOPPED()

Return True if the process returning status was stopped.

WSTOPSIG()

Return the signal that stopped the process that provided the status value.

WTERMSIG()

Return the signal that terminated the process that provided the status value.

abort()

Abort the interpreter immediately.

This function ‘dumps core’ or otherwise fails in the hardest way possible on the hosting operating system. This function never returns.

access()

Use the real uid/gid to test for access to a path.

path

Path to be tested; can be string or bytes

mode

Operating-system mode bitfield. Can be F_OK to test existence, or the inclusive-OR of R_OK, W_OK, and X_OK.

dir_fd

If not None, it should be a file descriptor open to a directory, and path should be relative; path will then be relative to that directory.

effective_ids

If True, access will use the effective uid/gid instead of the real uid/gid.

follow_symlinks

If False, and the last element of the path is a symbolic link, access will examine the symbolic link itself instead of the file the link points to.

dir_fd, effective_ids, and follow_symlinks may not be implemented

on your platform. If they are unavailable, using them will raise a NotImplementedError.

Note that most operations will use the effective uid/gid, therefore this

routine can be used in a suid/sgid environment to test if the invoking user has the specified access to the path.

chdir()

Change the current working directory to the specified path.

path may always be specified as a string. On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

chflags()

Set file flags.

If follow_symlinks is False, and the last element of the path is a symbolic

link, chflags will change flags on the symbolic link itself instead of the file the link points to.

follow_symlinks may not be implemented on your platform. If it is unavailable, using it will raise a NotImplementedError.

chmod()

Change the access permissions of a file.

path

Path to be modified. May always be specified as a str or bytes. On some platforms, path may also be specified as an open file descriptor. If this functionality is unavailable, using it raises an exception.

mode

Operating-system mode bitfield.

dir_fd

If not None, it should be a file descriptor open to a directory, and path should be relative; path will then be relative to that directory.

follow_symlinks

If False, and the last element of the path is a symbolic link, chmod will modify the symbolic link itself instead of the file the link points to.

It is an error to use dir_fd or follow_symlinks when specifying path as

an open file descriptor.

dir_fd and follow_symlinks may not be implemented on your platform.

If they are unavailable, using them will raise a NotImplementedError.

chown()

Change the owner and group id of path to the numeric uid and gid.

path

Path to be examined; can be string, bytes, or open-file-descriptor int.

dir_fd

If not None, it should be a file descriptor open to a directory, and path should be relative; path will then be relative to that directory.

follow_symlinks

If False, and the last element of the path is a symbolic link, stat will examine the symbolic link itself instead of the file the link points to.

path may always be specified as a string. On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

If follow_symlinks is False, and the last element of the path is a symbolic

link, chown will modify the symbolic link itself instead of the file the link points to.

It is an error to use dir_fd or follow_symlinks when specifying path as

an open file descriptor.

dir_fd and follow_symlinks may not be implemented on your platform.

If they are unavailable, using them will raise a NotImplementedError.

chroot()

Change root directory to path.

close()

Close a file descriptor.

closerange()

Closes all file descriptors in [fd_low, fd_high), ignoring errors.

confstr()

Return a string-valued system configuration variable.

cpu_count()

Return the number of CPUs in the system; return None if indeterminable.

This number is not equivalent to the number of CPUs the current process can use. The number of usable CPUs can be obtained with len(os.sched_getaffinity(0))

ctermid()

Return the name of the controlling terminal for this process.

device_encoding()

Return a string describing the encoding of a terminal’s file descriptor.

The file descriptor must be attached to a terminal. If the device is not a terminal, return None.

dup()

Return a duplicate of a file descriptor.

dup2()

Duplicate file descriptor.

execv()

Execute an executable path with arguments, replacing current process.

path

Path of executable file.

argv

Tuple or list of strings.

execve()

Execute an executable path with arguments, replacing current process.

path

Path of executable file.

argv

Tuple or list of strings.

env

Dictionary of strings mapping to strings.

fchdir()

Change to the directory of the given file descriptor.

fd must be opened on a directory, not a file. Equivalent to os.chdir(fd).

fchmod()

Change the access permissions of the file given by file descriptor fd.

Equivalent to os.chmod(fd, mode).

fchown()

Change the owner and group id of the file specified by file descriptor.

Equivalent to os.chown(fd, uid, gid).

fork()

Fork a child process.

Return 0 to child process and PID of child to parent process.

forkpty()

Fork a new process with a new pseudo-terminal as controlling tty.

Returns a tuple of (pid, master_fd). Like fork(), return pid of 0 to the child process, and pid of child to the parent process. To both, return fd of newly opened pseudo-terminal.

fpathconf()

Return the configuration limit name for the file descriptor fd.

If there is no limit, return -1.

fspath()

Return the file system path representation of the object.

If the object is str or bytes, then allow it to pass through as-is. If the object defines __fspath__(), then return the result of that method. All other types raise a TypeError.

fstat()

Perform a stat system call on the given file descriptor.

Like stat(), but for an open file descriptor. Equivalent to os.stat(fd).

fstatvfs()

Perform an fstatvfs system call on the given fd.

Equivalent to statvfs(fd).

fsync()

Force write of fd to disk.

ftruncate()

Truncate a file, specified by file descriptor, to a specific length.

get_blocking(fd) → bool

Get the blocking mode of the file descriptor: False if the O_NONBLOCK flag is set, True if the flag is cleared.

get_inheritable()

Get the close-on-exe flag of the specified file descriptor.

get_terminal_size()

Return the size of the terminal window as (columns, lines).

The optional argument fd (default standard output) specifies which file descriptor should be queried.

If the file descriptor is not connected to a terminal, an OSError is thrown.

This function will only be defined if an implementation is available for this system.

shutil.get_terminal_size is the high-level function which should normally be used, os.get_terminal_size is the low-level implementation.

getcwd()

Return a unicode string representing the current working directory.

getcwdb()

Return a bytes string representing the current working directory.

getegid()

Return the current process’s effective group id.

geteuid()

Return the current process’s effective user id.

getgid()

Return the current process’s group id.

getgrouplist(user, group) → list of groups to which a user belongs

Returns a list of groups to which a user belongs.

user: username to lookup group: base group id of the user

getgroups()

Return list of supplemental group IDs for the process.

getloadavg()

Return average recent system load information.

Return the number of processes in the system run queue averaged over the last 1, 5, and 15 minutes as a tuple of three floats. Raises OSError if the load average was unobtainable.

getlogin()

Return the actual login name.

getpgid()

Call the system call getpgid(), and return the result.

getpgrp()

Return the current process group id.

getpid()

Return the current process id.

getppid()

Return the parent’s process id.

If the parent process has already exited, Windows machines will still return its id; others systems will return the id of the ‘init’ process (1).

getpriority()

Return program scheduling priority.

getsid()

Call the system call getsid(pid) and return the result.

getuid()

Return the current process’s user id.

initgroups(username, gid) → None

Call the system initgroups() to initialize the group access list with all of the groups of which the specified username is a member, plus the specified group id.

isatty()

Return True if the fd is connected to a terminal.

Return True if the file descriptor is an open file descriptor connected to the slave end of a terminal.

kill()

Kill a process with a signal.

killpg()

Kill a process group with a signal.

lchflags()

Set file flags.

This function will not follow symbolic links. Equivalent to chflags(path, flags, follow_symlinks=False).

lchmod()

Change the access permissions of a file, without following symbolic links.

If path is a symlink, this affects the link itself rather than the target. Equivalent to chmod(path, mode, follow_symlinks=False).”

lchown()

Change the owner and group id of path to the numeric uid and gid.

This function will not follow symbolic links. Equivalent to os.chown(path, uid, gid, follow_symlinks=False).

Create a hard link to a file.

If either src_dir_fd or dst_dir_fd is not None, it should be a file

descriptor open to a directory, and the respective path string (src or dst) should be relative; the path will then be relative to that directory.

If follow_symlinks is False, and the last element of src is a symbolic

link, link will create a link to the symbolic link itself instead of the file the link points to.

src_dir_fd, dst_dir_fd, and follow_symlinks may not be implemented on your

platform. If they are unavailable, using them will raise a NotImplementedError.

listdir()

Return a list containing the names of the files in the directory.

path can be specified as either str or bytes. If path is bytes,

the filenames returned will also be bytes; in all other circumstances the filenames returned will be str.

If path is None, uses the path=’.’. On some platforms, path may also be specified as an open file descriptor;

the file descriptor must refer to a directory. If this functionality is unavailable, using it raises NotImplementedError.

The list is in arbitrary order. It does not include the special entries ‘.’ and ‘..’ even if they are present in the directory.

lockf()

Apply, test or remove a POSIX lock on an open file descriptor.

fd

An open file descriptor.

command

One of F_LOCK, F_TLOCK, F_ULOCK or F_TEST.

length

The number of bytes to lock, starting at the current position.

lseek()

Set the position of a file descriptor. Return the new position.

Return the new cursor position in number of bytes relative to the beginning of the file.

lstat()

Perform a stat system call on the given path, without following symbolic links.

Like stat(), but do not follow symbolic links. Equivalent to stat(path, follow_symlinks=False).

major()

Extracts a device major number from a raw device number.

makedev()

Composes a raw device number from the major and minor device numbers.

minor()

Extracts a device minor number from a raw device number.

mkdir()

Create a directory.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

The mode argument is ignored on Windows.

mkfifo()

Create a “fifo” (a POSIX named pipe).

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

mknod()

Create a node in the file system.

Create a node in the file system (file, device special file or named pipe) at path. mode specifies both the permissions to use and the type of node to be created, being combined (bitwise OR) with one of S_IFREG, S_IFCHR, S_IFBLK, and S_IFIFO. If S_IFCHR or S_IFBLK is set on mode, device defines the newly created device special file (probably using os.makedev()). Otherwise device is ignored.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

nice()

Add increment to the priority of process and return the new priority.

open()

Open a file for low level IO. Returns a file descriptor (integer).

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

openpty()

Open a pseudo-terminal.

Return a tuple of (master_fd, slave_fd) containing open file descriptors for both the master and slave ends.

pathconf()

Return the configuration limit name for the file or directory path.

If there is no limit, return -1. On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

pipe()

Create a pipe.

Returns a tuple of two file descriptors:

(read_fd, write_fd)

pread()

Read a number of bytes from a file descriptor starting at a particular offset.

Read length bytes from file descriptor fd, starting at offset bytes from the beginning of the file. The file offset remains unchanged.

putenv()

Change or add an environment variable.

pwrite()

Write bytes to a file descriptor starting at a particular offset.

Write buffer to fd, starting at offset bytes from the beginning of the file. Returns the number of bytes writte. Does not change the current file offset.

read()

Read from a file descriptor. Returns a bytes object.

Return a string representing the path to which the symbolic link points.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

readv()

Read from a file descriptor fd into an iterable of buffers.

The buffers should be mutable buffers accepting bytes. readv will transfer data into each buffer until it is full and then move on to the next buffer in the sequence to hold the rest of the data.

readv returns the total number of bytes read, which may be less than the total capacity of all the buffers.

register_at_fork()

Register callables to be called when forking a new process.

before

A callable to be called in the parent before the fork() syscall.

after_in_child

A callable to be called in the child after fork().

after_in_parent

A callable to be called in the parent after fork().

‘before’ callbacks are called in reverse order. ‘after_in_child’ and ‘after_in_parent’ callbacks are called in order.

remove()

Remove a file (same as unlink()).

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

rename()

Rename a file or directory.

If either src_dir_fd or dst_dir_fd is not None, it should be a file

descriptor open to a directory, and the respective path string (src or dst) should be relative; the path will then be relative to that directory.

src_dir_fd and dst_dir_fd, may not be implemented on your platform.

If they are unavailable, using them will raise a NotImplementedError.

replace()

Rename a file or directory, overwriting the destination.

If either src_dir_fd or dst_dir_fd is not None, it should be a file

descriptor open to a directory, and the respective path string (src or dst) should be relative; the path will then be relative to that directory.

src_dir_fd and dst_dir_fd, may not be implemented on your platform.

If they are unavailable, using them will raise a NotImplementedError.”

rmdir()

Remove a directory.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

scandir()

Return an iterator of DirEntry objects for given path.

path can be specified as either str, bytes or path-like object. If path is bytes, the names of yielded DirEntry objects will also be bytes; in all other circumstances they will be str.

If path is None, uses the path=’.’.

sched_get_priority_max()

Get the maximum scheduling priority for policy.

sched_get_priority_min()

Get the minimum scheduling priority for policy.

sched_yield()

Voluntarily relinquish the CPU.

sendfile(out, in, offset, count) → byteswritten
sendfile(out, in, offset, count[, headers][, trailers], flags=0)

-> byteswritten

Copy count bytes from file descriptor in to file descriptor out.

set_blocking(fd, blocking)

Set the blocking mode of the specified file descriptor. Set the O_NONBLOCK flag if blocking is False, clear the O_NONBLOCK flag otherwise.

set_inheritable()

Set the inheritable flag of the specified file descriptor.

setegid()

Set the current process’s effective group id.

seteuid()

Set the current process’s effective user id.

setgid()

Set the current process’s group id.

setgroups()

Set the groups of the current process to list.

setpgid()

Call the system call setpgid(pid, pgrp).

setpgrp()

Make the current process the leader of its process group.

setpriority()

Set program scheduling priority.

setregid()

Set the current process’s real and effective group ids.

setreuid()

Set the current process’s real and effective user ids.

setsid()

Call the system call setsid().

setuid()

Set the current process’s user id.

stat()

Perform a stat system call on the given path.

path

Path to be examined; can be string, bytes, path-like object or open-file-descriptor int.

dir_fd

If not None, it should be a file descriptor open to a directory, and path should be a relative string; path will then be relative to that directory.

follow_symlinks

If False, and the last element of the path is a symbolic link, stat will examine the symbolic link itself instead of the file the link points to.

dir_fd and follow_symlinks may not be implemented

on your platform. If they are unavailable, using them will raise a NotImplementedError.

It’s an error to use dir_fd or follow_symlinks when specifying path as

an open file descriptor.

statvfs()

Perform a statvfs system call on the given path.

path may always be specified as a string. On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

strerror()

Translate an error code to a message string.

Create a symbolic link pointing to src named dst.

target_is_directory is required on Windows if the target is to be

interpreted as a directory. (On Windows, symlink requires Windows 6.0 or greater, and raises a NotImplementedError otherwise.) target_is_directory is ignored on non-Windows platforms.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

sync()

Force write of everything to disk.

sysconf()

Return an integer-valued system configuration variable.

system()

Execute the command in a subshell.

tcgetpgrp()

Return the process group associated with the terminal specified by fd.

tcsetpgrp()

Set the process group associated with the terminal specified by fd.

times()

Return a collection containing process timing information.

The object returned behaves like a named tuple with these fields:

(utime, stime, cutime, cstime, elapsed_time)

All fields are floating point numbers.

truncate()

Truncate a file, specified by path, to a specific length.

On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

ttyname()

Return the name of the terminal device connected to ‘fd’.

fd

Integer file descriptor handle.

umask()

Set the current numeric umask and return the previous umask.

uname()

Return an object identifying the current operating system.

The object behaves like a named tuple with the following fields:

(sysname, nodename, release, version, machine)

Remove a file (same as remove()).

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

dir_fd may not be implemented on your platform.

If it is unavailable, using it will raise a NotImplementedError.

unsetenv()

Delete an environment variable.

urandom()

Return a bytes object containing random bytes suitable for cryptographic use.

utime()

Set the access and modified time of path.

path may always be specified as a string. On some platforms, path may also be specified as an open file descriptor.

If this functionality is unavailable, using it raises an exception.

If times is not None, it must be a tuple (atime, mtime);

atime and mtime should be expressed as float seconds since the epoch.

If ns is specified, it must be a tuple (atime_ns, mtime_ns);

atime_ns and mtime_ns should be expressed as integer nanoseconds since the epoch.

If times is None and ns is unspecified, utime uses the current time. Specifying tuples for both times and ns is an error.

If dir_fd is not None, it should be a file descriptor open to a directory,

and path should be relative; path will then be relative to that directory.

If follow_symlinks is False, and the last element of the path is a symbolic

link, utime will modify the symbolic link itself instead of the file the link points to.

It is an error to use dir_fd or follow_symlinks when specifying path

as an open file descriptor.

dir_fd and follow_symlinks may not be available on your platform.

If they are unavailable, using them will raise a NotImplementedError.

wait()

Wait for completion of a child process.

Returns a tuple of information about the child process:

(pid, status)

wait3()

Wait for completion of a child process.

Returns a tuple of information about the child process:

(pid, status, rusage)

wait4()

Wait for completion of a specific child process.

Returns a tuple of information about the child process:

(pid, status, rusage)

waitpid()

Wait for completion of a given child process.

Returns a tuple of information regarding the child process:

(pid, status)

The options argument is ignored on Windows.

write()

Write a bytes object to a file descriptor.

writev()

Iterate over buffers, and write the contents of each to a file descriptor.

Returns the total number of bytes written. buffers must be a sequence of bytes-like objects.

makedirs(name [, mode=0o777][, exist_ok=False])

Super-mkdir; create a leaf directory and all intermediate ones. Works like mkdir, except that any intermediate path segment (not just the rightmost) will be created if it does not exist. If the target directory already exists, raise an OSError if exist_ok is False. Otherwise no exception is raised. This is recursive.

removedirs(name)

Super-rmdir; remove a leaf directory and all empty intermediate ones. Works like rmdir except that, if the leaf directory is successfully removed, directories corresponding to rightmost path segments will be pruned away until either the whole path is consumed or an error occurs. Errors during this latter phase are ignored – they generally mean that a directory was not empty.

renames(old, new)

Super-rename; create directories as necessary and delete any left empty. Works like rename, except creation of any intermediate directories needed to make the new pathname good is attempted first. After the rename, directories corresponding to rightmost path segments of the old name will be pruned until either the whole path is consumed or a nonempty directory is found.

Note: this function can fail with the new directory structure made if you lack permissions needed to unlink the leaf directory or file.

walk(top, topdown=True, onerror=None, followlinks=False)

Directory tree generator.

For each directory in the directory tree rooted at top (including top itself, but excluding ‘.’ and ‘..’), yields a 3-tuple

dirpath, dirnames, filenames

dirpath is a string, the path to the directory. dirnames is a list of the names of the subdirectories in dirpath (excluding ‘.’ and ‘..’). filenames is a list of the names of the non-directory files in dirpath. Note that the names in the lists are just names, with no path components. To get a full path (which begins with top) to a file or directory in dirpath, do os.path.join(dirpath, name).

If optional arg ‘topdown’ is true or not specified, the triple for a directory is generated before the triples for any of its subdirectories (directories are generated top down). If topdown is false, the triple for a directory is generated after the triples for all of its subdirectories (directories are generated bottom up).

When topdown is true, the caller can modify the dirnames list in-place (e.g., via del or slice assignment), and walk will only recurse into the subdirectories whose names remain in dirnames; this can be used to prune the search, or to impose a specific order of visiting. Modifying dirnames when topdown is false is ineffective, since the directories in dirnames have already been generated by the time dirnames itself is generated. No matter the value of topdown, the list of subdirectories is retrieved before the tuples for the directory and its subdirectories are generated.

By default errors from the os.scandir() call are ignored. If optional arg ‘onerror’ is specified, it should be a function; it will be called with one argument, an OSError instance. It can report the error to continue with the walk, or raise the exception to abort the walk. Note that the filename is available as the filename attribute of the exception object.

By default, os.walk does not follow symbolic links to subdirectories on systems that support them. In order to get this functionality, set the optional argument ‘followlinks’ to true.

Caution: if you pass a relative pathname for top, don’t change the current working directory between resumptions of walk. walk never changes the current directory, and assumes that the client doesn’t either.

Example:

import os from os.path import join, getsize for root, dirs, files in os.walk(‘python/Lib/email’):

print(root, “consumes”, end=”“) print(sum([getsize(join(root, name)) for name in files]), end=”“) print(“bytes in”, len(files), “non-directory files”) if ‘CVS’ in dirs:

dirs.remove(‘CVS’) # don’t visit CVS directories

fwalk(top='.', topdown=True, onerror=None, *, follow_symlinks=False, dir_fd=None)

Directory tree generator.

This behaves exactly like walk(), except that it yields a 4-tuple

dirpath, dirnames, filenames, dirfd

dirpath, dirnames and filenames are identical to walk() output, and dirfd is a file descriptor referring to the directory dirpath.

The advantage of fwalk() over walk() is that it’s safe against symlink races (when follow_symlinks is False).

If dir_fd is not None, it should be a file descriptor open to a directory,

and top should be relative; top will then be relative to that directory. (dir_fd is always supported for fwalk.)

Caution: Since fwalk() yields file descriptors, those are only valid until the next iteration step, so you should dup() them if you want to keep them for a longer period.

Example:

import os for root, dirs, files, rootfd in os.fwalk(‘python/Lib/email’):

print(root, “consumes”, end=”“) print(sum([os.stat(name, dir_fd=rootfd).st_size for name in files]),

end=”“)

print(“bytes in”, len(files), “non-directory files”) if ‘CVS’ in dirs:

dirs.remove(‘CVS’) # don’t visit CVS directories

execl(file, *args)

Execute the executable file with argument list args, replacing the current process.

execle(file, *args, env)

Execute the executable file with argument list args and environment env, replacing the current process.

execlp(file, *args)

Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process.

execlpe(file, *args, env)

Execute the executable file (which is searched for along $PATH) with argument list args and environment env, replacing the current process.

execvp(file, args)

Execute the executable file (which is searched for along $PATH) with argument list args, replacing the current process. args may be a list or tuple of strings.

execvpe(file, args, env)

Execute the executable file (which is searched for along $PATH) with argument list args and environment env , replacing the current process. args may be a list or tuple of strings.

getenv(key, default=None)

Get an environment variable, return None if it doesn’t exist. The optional second argument can specify an alternate default. key, default and the result are str.

getenvb(key, default=None)

Get an environment variable, return None if it doesn’t exist. The optional second argument can specify an alternate default. key, default and the result are bytes.

spawnv(mode, file, args) → integer

Execute file with arguments from args in a subprocess. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnve(mode, file, args, env) → integer

Execute file with arguments from args in a subprocess with the specified environment. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnvp(mode, file, args) → integer

Execute file (which is looked for along $PATH) with arguments from args in a subprocess. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnvpe(mode, file, args, env) → integer

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnl(mode, file, *args) → integer

Execute file with arguments from args in a subprocess. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnle(mode, file, *args, env) → integer

Execute file with arguments from args in a subprocess with the supplied environment. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnlp(mode, file, *args) → integer

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.

spawnlpe(mode, file, *args, env) → integer

Execute file (which is looked for along $PATH) with arguments from args in a subprocess with the supplied environment. If mode == P_NOWAIT return the pid of the process. If mode == P_WAIT return the process’s exit code if it exits normally; otherwise return -SIG, where SIG is the signal that killed it.