Module Async_unix.UnixSource

this_process_became_child_of_init returns a deferred that becomes determined when the current process becomes a child of init(8). This is useful for determining whether one's parent has died, because in that case init will become one's parent.

See Linux_ext.pr_set_pdeathsig : Signal.t -> unit for a related way to get information about parent death.

?poll_delay controls how often to check.

cores () Returns the number of cores.

with_file file ~mode ~perm ~f opens file, and applies f to the resulting file descriptor. When the result of f becomes determined, it closes the descriptor and returns the result of f.

If lock is supplied, then the file descriptor is locked before calling f with the specified lock_mechanism. Note that it is not unlocked before close, which might be significant if this file descriptor is held elsewhere (e.g., by fork() or dup()).

fcntl_getfl and fcntl_setf are deferred wrappers around the corresponding functions in Core_unix for accessing the open-file-descriptor table.

lockf fd lock_mode ?len locks the section of the open file fd specified by the current file position and len (see man lockf). It returns when the lock has been acquired. It raises if fd is closed.

Warning: lockf locks are held per-process, so taking the lock on the same file multiple times in the same process is going to break in terrible ways.

Note that, despite the name, this function does not call the UNIX lockf() system call; rather it calls fcntl() with F_SETLKW

try_lockf fd lock_mode ?len attempts to lock the section of the open file fd specified by the current file position and len (see man lockf). It returns true if it acquired the lock. It raises if fd is closed.

Note that, despite the name, this function does not call the UNIX lockf() system call; rather it calls fcntl() with F_SETLK

test_lockf fd ?len checks the lock on section of the open file fd specified by the current file position and len. If the section is unlocked or locked by this process, it returns true, else it returns false. It raises if fd is closed.

Note that, despite the name, this function does not call the UNIX lockf() system call; rather it calls fcntl() with F_GETLK

unlockf fd ?len unlocks the section of the open file fd specified by the current file position and len. It raises if fd is closed.

Note that, despite the name, this function does not call the UNIX lockf() system call; rather it calls fcntl() with F_UNLCK

flock fd lock_mode locks the open file fd (see man 2 flock). It returns when the lock has been acquired. It raises if fd is closed.

try_flock fd lock_mode attempts to lock the open file fd (see man 2 flock). It returns true if it acquired the lock or false if a conflicting lock was already present. It raises if fd is closed.

funlock fd unlocks the open file fd (see man 2 flock). It raises if fd is closed.

readdir_opt dir_handle returns the next directory member, or None when there are no more directory members to return.

The info supplied to pipe is debugging information that will be included in the returned Fds.

Create a named pipe with the given permissions.

mkstemp prefix creates and opens a unique temporary file with prefix, automatically appending a suffix of six random characters to make the name unique. Unlike C's mkstemp, prefix should not include six X's at the end.

• raises Unix_error

  on errors.

Time functions.

fork_exec ~prog ~argv ?path ?env forks and execs prog with argv, and returns the child pid. If use_path = true (the default) and prog doesn't contain a slash, then fork_exec searches the PATH environment variable for prog. If env is supplied, it specifies the environment when prog is executed.

If env contains multiple bindings for the same variable, the last takes precedence. In the case of `Extend, bindings in env take precedence over the existing environment. See Unix.exec.

waitpid pid returns a deferred that becomes determined with the child's exit status, when the child process with process id pid exits. waitpid_exn is like waitpid, except the result only becomes determined if the child exits with status zero; it raises if the child terminates in any other way.

Same as waitpid, but guarantees that the resulting Deferred is determined in the same async job as the wait system call, so that it's safe to keep using the pid if the deferred is not determined.

sockaddr_blocking_sexp is like sockaddr, with of_sexp that performs DNS lookup to resolve Inet_addr.t.

Structure of entries in the passwd database.

Structure of entries in the groups database.

Gets the information using the socket-based netlink interface, which can block; see https://www.infradead.org/~tgr/libnl/doc/core.html.

Returns the name of the user executing the process.

This returns a deferred because the username may need to be looked up in what is essentially a database elsewhere on the network (winbound user, or NIS). This also means that this function isn't guaranteed to succeed: it may raise instead.

Same as username.