NAME¶
Unix - Interface to the Unix system
Module¶
Module Unix
Documentation¶
Module
Unix
:
sig end
Interface to the Unix system
=== Error report ===
type error =
| E2BIG (* Argument list too long *)
| EACCES (* Permission denied *)
| EAGAIN (* Resource temporarily unavailable; try again *)
| EBADF (* Bad file descriptor *)
| EBUSY (* Resource unavailable *)
| ECHILD (* No child process *)
| EDEADLK (* Resource deadlock would occur *)
| EDOM (* Domain error for math functions, etc. *)
| EEXIST (* File exists *)
| EFAULT (* Bad address *)
| EFBIG (* File too large *)
| EINTR (* Function interrupted by signal *)
| EINVAL (* Invalid argument *)
| EIO (* Hardware I/O error *)
| EISDIR (* Is a directory *)
| EMFILE (* Too many open files by the process *)
| EMLINK (* Too many links *)
| ENAMETOOLONG (* Filename too long *)
| ENFILE (* Too many open files in the system *)
| ENODEV (* No such device *)
| ENOENT (* No such file or directory *)
| ENOEXEC (* Not an executable file *)
| ENOLCK (* No locks available *)
| ENOMEM (* Not enough memory *)
| ENOSPC (* No space left on device *)
| ENOSYS (* Function not supported *)
| ENOTDIR (* Not a directory *)
| ENOTEMPTY (* Directory not empty *)
| ENOTTY (* Inappropriate I/O control operation *)
| ENXIO (* No such device or address *)
| EPERM (* Operation not permitted *)
| EPIPE (* Broken pipe *)
| ERANGE (* Result too large *)
| EROFS (* Read-only file system *)
| ESPIPE (* Invalid seek e.g. on a pipe *)
| ESRCH (* No such process *)
| EXDEV (* Invalid link *)
| EWOULDBLOCK (* Operation would block *)
| EINPROGRESS (* Operation now in progress *)
| EALREADY (* Operation already in progress *)
| ENOTSOCK (* Socket operation on non-socket *)
| EDESTADDRREQ (* Destination address required *)
| EMSGSIZE (* Message too long *)
| EPROTOTYPE (* Protocol wrong type for socket *)
| ENOPROTOOPT (* Protocol not available *)
| EPROTONOSUPPORT (* Protocol not supported *)
| ESOCKTNOSUPPORT (* Socket type not supported *)
| EOPNOTSUPP (* Operation not supported on socket *)
| EPFNOSUPPORT (* Protocol family not supported *)
| EAFNOSUPPORT (* Address family not supported by protocol family *)
| EADDRINUSE (* Address already in use *)
| EADDRNOTAVAIL (* Can't assign requested address *)
| ENETDOWN (* Network is down *)
| ENETUNREACH (* Network is unreachable *)
| ENETRESET (* Network dropped connection on reset *)
| ECONNABORTED (* Software caused connection abort *)
| ECONNRESET (* Connection reset by peer *)
| ENOBUFS (* No buffer space available *)
| EISCONN (* Socket is already connected *)
| ENOTCONN (* Socket is not connected *)
| ESHUTDOWN (* Can't send after socket shutdown *)
| ETOOMANYREFS (* Too many references: can't splice *)
| ETIMEDOUT (* Connection timed out *)
| ECONNREFUSED (* Connection refused *)
| EHOSTDOWN (* Host is down *)
| EHOSTUNREACH (* No route to host *)
| ELOOP (* Too many levels of symbolic links *)
| EOVERFLOW (* File size or position not representable *)
| EUNKNOWNERR
of int (* Unknown error *)
The type of error codes. Errors defined in the POSIX standard and additional
errors from UNIX98 and BSD. All other errors are mapped to EUNKNOWNERR.
exception Unix_error of error * string * string
Raised by the system calls below when an error is encountered. The first
component is the error code; the second component is the function name; the
third component is the string parameter to the function, if it has one, or the
empty string otherwise.
val error_message :
error -> string
Return a string describing the given error code.
val handle_unix_error :
('a -> 'b) -> 'a -> 'b
handle_unix_error f x applies
f to
x and returns the
result. If the exception
Unix_error is raised, it prints a message
describing the error and exits with code 2.
=== Access to the process environment ===
val environment :
unit -> string array
Return the process environment, as an array of strings with the format
``variable=value''.
val getenv :
string -> string
Return the value associated to a variable in the process environment. Raise
Not_found if the variable is unbound. (This function is identical to
Sys.getenv .)
val putenv :
string -> string -> unit
Unix.putenv name value sets the value associated to a variable in the
process environment.
name is the name of the environment variable, and
value its new associated value.
=== Process handling ===
type process_status =
| WEXITED
of int (* The process terminated normally by
exit ; the argument is the return code. *)
| WSIGNALED
of int (* The process was killed by a
signal; the argument is the signal number. *)
| WSTOPPED
of int (* The process was stopped by a
signal; the argument is the signal number. *)
The termination status of a process. See module
Sys for the definitions
of the standard signal numbers. Note that they are not the numbers used by the
OS.
type wait_flag =
| WNOHANG (* do not block if no child has died yet, but immediately return with
a pid equal to 0. *)
| WUNTRACED (* report also the children that receive stop signals. *)
Flags for
Unix.waitpid .
val execv :
string -> string array -> 'a
execv prog args execute the program in file
prog , with the
arguments
args , and the current process environment. These
execv* functions never return: on success, the current program is
replaced by the new one; on failure, a
Unix.Unix_error exception is
raised.
val execve :
string -> string array -> string array -> 'a
Same as
Unix.execv , except that the third argument provides the
environment to the program executed.
val execvp :
string -> string array -> 'a
Same as
Unix.execv , except that the program is searched in the path.
val execvpe :
string -> string array -> string array ->
'a
Same as
Unix.execve , except that the program is searched in the path.
val fork :
unit -> int
Fork a new process. The returned integer is 0 for the child process, the pid of
the child process for the parent process.
val wait :
unit -> int * process_status
Wait until one of the children processes die, and return its pid and termination
status.
val waitpid :
wait_flag list -> int -> int * process_status
Same as
Unix.wait , but waits for the child process whose pid is given. A
pid of
-1 means wait for any child. A pid of
0 means wait for
any child in the same process group as the current process. Negative pid
arguments represent process groups. The list of options indicates whether
waitpid should return immediately without waiting, or also report
stopped children.
val system :
string -> process_status
Execute the given command, wait until it terminates, and return its termination
status. The string is interpreted by the shell
/bin/sh and therefore
can contain redirections, quotes, variables, etc. The result
WEXITED
127 indicates that the shell couldn't be executed.
val getpid :
unit -> int
Return the pid of the process.
val getppid :
unit -> int
Return the pid of the parent process.
val nice :
int -> int
Change the process priority. The integer argument is added to the ``nice''
value. (Higher values of the ``nice'' value mean lower priorities.) Return the
new nice value.
=== Basic file input/output ===
type file_descr
The abstract type of file descriptors.
val stdin :
file_descr
File descriptor for standard input.
val stdout :
file_descr
File descriptor for standard output.
val stderr :
file_descr
File descriptor for standard error.
type open_flag =
| O_RDONLY (* Open for reading *)
| O_WRONLY (* Open for writing *)
| O_RDWR (* Open for reading and writing *)
| O_NONBLOCK (* Open in non-blocking mode *)
| O_APPEND (* Open for append *)
| O_CREAT (* Create if nonexistent *)
| O_TRUNC (* Truncate to 0 length if existing *)
| O_EXCL (* Fail if existing *)
| O_NOCTTY (* Don't make this dev a controlling tty *)
| O_DSYNC (* Writes complete as `Synchronised I/O data integrity completion' *)
| O_SYNC (* Writes complete as `Synchronised I/O file integrity completion' *)
| O_RSYNC (* Reads complete as writes (depending on O_SYNC/O_DSYNC) *)
The flags to
Unix.openfile .
type file_perm =
int
The type of file access rights, e.g.
0o640 is read and write for user,
read for group, none for others
val openfile :
string -> open_flag list -> file_perm ->
file_descr
Open the named file with the given flags. Third argument is the permissions to
give to the file if it is created. Return a file descriptor on the named file.
val close :
file_descr -> unit
Close a file descriptor.
val read :
file_descr -> string -> int -> int -> int
read fd buff ofs len reads
len characters from descriptor
fd , storing them in string
buff , starting at position
ofs in string
buff . Return the number of characters actually
read.
val write :
file_descr -> string -> int -> int -> int
write fd buff ofs len writes
len characters to descriptor
fd , taking them from string
buff , starting at position
ofs in string
buff . Return the number of characters actually
written.
write repeats the writing operation until all characters have
been written or an error occurs.
val single_write :
file_descr -> string -> int -> int ->
int
Same as
write , but attempts to write only once. Thus, if an error
occurs,
single_write guarantees that no data has been written.
=== Interfacing with the standard input/output library ===
val in_channel_of_descr :
file_descr -> Pervasives.in_channel
Create an input channel reading from the given descriptor. The channel is
initially in binary mode; use
set_binary_mode_in ic false if text mode
is desired.
val out_channel_of_descr :
file_descr -> Pervasives.out_channel
Create an output channel writing on the given descriptor. The channel is
initially in binary mode; use
set_binary_mode_out oc false if text mode
is desired.
val descr_of_in_channel :
Pervasives.in_channel -> file_descr
Return the descriptor corresponding to an input channel.
val descr_of_out_channel :
Pervasives.out_channel -> file_descr
Return the descriptor corresponding to an output channel.
=== Seeking and truncating ===
type seek_command =
| SEEK_SET (* indicates positions relative to the beginning of the file *)
| SEEK_CUR (* indicates positions relative to the current position *)
| SEEK_END (* indicates positions relative to the end of the file *)
Positioning modes for
Unix.lseek .
val lseek :
file_descr -> int -> seek_command -> int
Set the current position for a file descriptor
val truncate :
string -> int -> unit
Truncates the named file to the given size.
val ftruncate :
file_descr -> int -> unit
Truncates the file corresponding to the given descriptor to the given size.
=== File status ===
type file_kind =
| S_REG (* Regular file *)
| S_DIR (* Directory *)
| S_CHR (* Character device *)
| S_BLK (* Block device *)
| S_LNK (* Symbolic link *)
| S_FIFO (* Named pipe *)
| S_SOCK (* Socket *)
type stats = {
st_dev :
int ; (* Device number *)
st_ino :
int ; (* Inode number *)
st_kind :
file_kind ; (* Kind of the file *)
st_perm :
file_perm ; (* Access rights *)
st_nlink :
int ; (* Number of links *)
st_uid :
int ; (* User id of the owner *)
st_gid :
int ; (* Group ID of the file's group *)
st_rdev :
int ; (* Device minor number *)
st_size :
int ; (* Size in bytes *)
st_atime :
float ; (* Last access time *)
st_mtime :
float ; (* Last modification time *)
st_ctime :
float ; (* Last status change time *)
}
The information returned by the
Unix.stat calls.
val stat :
string -> stats
Return the information for the named file.
val lstat :
string -> stats
Same as
Unix.stat , but in case the file is a symbolic link, return the
information for the link itself.
val fstat :
file_descr -> stats
Return the information for the file associated with the given descriptor.
val isatty :
file_descr -> bool
Return
true if the given file descriptor refers to a terminal or console
window,
false otherwise.
=== File operations on large files ===
module LargeFile : sig end
File operations on large files. This sub-module provides 64-bit variants of the
functions
Unix.lseek (for positioning a file descriptor),
Unix.truncate and
Unix.ftruncate (for changing the size of a
file), and
Unix.stat ,
Unix.lstat and
Unix.fstat (for
obtaining information on files). These alternate functions represent positions
and sizes by 64-bit integers (type
int64 ) instead of regular integers
(type
int ), thus allowing operating on files whose sizes are greater
than
max_int .
=== Operations on file names ===
val unlink :
string -> unit
Removes the named file
val rename :
string -> string -> unit
rename old new changes the name of a file from
old to
new .
val link :
string -> string -> unit
link source dest creates a hard link named
dest to the file named
source .
=== File permissions and ownership ===
type access_permission =
| R_OK (* Read permission *)
| W_OK (* Write permission *)
| X_OK (* Execution permission *)
| F_OK (* File exists *)
Flags for the
Unix.access call.
val chmod :
string -> file_perm -> unit
Change the permissions of the named file.
val fchmod :
file_descr -> file_perm -> unit
Change the permissions of an opened file.
val chown :
string -> int -> int -> unit
Change the owner uid and owner gid of the named file.
val fchown :
file_descr -> int -> int -> unit
Change the owner uid and owner gid of an opened file.
val umask :
int -> int
Set the process's file mode creation mask, and return the previous mask.
val access :
string -> access_permission list -> unit
Check that the process has the given permissions over the named file. Raise
Unix_error otherwise.
=== Operations on file descriptors ===
val dup :
file_descr -> file_descr
Return a new file descriptor referencing the same file as the given descriptor.
val dup2 :
file_descr -> file_descr -> unit
dup2 fd1 fd2 duplicates
fd1 to
fd2 , closing
fd2 if
already opened.
val set_nonblock :
file_descr -> unit
Set the ``non-blocking'' flag on the given descriptor. When the non-blocking
flag is set, reading on a descriptor on which there is temporarily no data
available raises the
EAGAIN or
EWOULDBLOCK error instead of
blocking; writing on a descriptor on which there is temporarily no room for
writing also raises
EAGAIN or
EWOULDBLOCK .
val clear_nonblock :
file_descr -> unit
Clear the ``non-blocking'' flag on the given descriptor. See
Unix.set_nonblock .
val set_close_on_exec :
file_descr -> unit
Set the ``close-on-exec'' flag on the given descriptor. A descriptor with the
close-on-exec flag is automatically closed when the current process starts
another program with one of the
exec functions.
val clear_close_on_exec :
file_descr -> unit
Clear the ``close-on-exec'' flag on the given descriptor. See
Unix.set_close_on_exec .
=== Directories ===
val mkdir :
string -> file_perm -> unit
Create a directory with the given permissions.
val rmdir :
string -> unit
Remove an empty directory.
val chdir :
string -> unit
Change the process working directory.
val getcwd :
unit -> string
Return the name of the current working directory.
val chroot :
string -> unit
Change the process root directory.
type dir_handle
The type of descriptors over opened directories.
val opendir :
string -> dir_handle
Open a descriptor on a directory
val readdir :
dir_handle -> string
Return the next entry in a directory.
Raises End_of_file when the end of the directory has been reached.
val rewinddir :
dir_handle -> unit
Reposition the descriptor to the beginning of the directory
val closedir :
dir_handle -> unit
Close a directory descriptor.
=== Pipes and redirections ===
val pipe :
unit -> file_descr * file_descr
Create a pipe. The first component of the result is opened for reading, that's
the exit to the pipe. The second component is opened for writing, that's the
entrance to the pipe.
val mkfifo :
string -> file_perm -> unit
Create a named pipe with the given permissions.
=== High-level process and redirection management ===
val create_process :
string -> string array -> file_descr
-> file_descr -> file_descr -> int
create_process prog args new_stdin new_stdout new_stderr forks a new
process that executes the program in file
prog , with arguments
args . The pid of the new process is returned immediately; the new
process executes concurrently with the current process. The standard input and
outputs of the new process are connected to the descriptors
new_stdin ,
new_stdout and
new_stderr . Passing e.g.
stdout for
new_stdout prevents the redirection and causes the new process to have
the same standard output as the current process. The executable file
prog is searched in the path. The new process has the same environment
as the current process.
val create_process_env :
string -> string array ->
string array -> file_descr -> file_descr -> file_descr ->
int
create_process_env prog args env new_stdin new_stdout new_stderr works as
Unix.create_process , except that the extra argument
env
specifies the environment passed to the program.
val open_process_in :
string -> Pervasives.in_channel
High-level pipe and process management. This function runs the given command in
parallel with the program. The standard output of the command is redirected to
a pipe, which can be read via the returned input channel. The command is
interpreted by the shell
/bin/sh (cf.
system ).
val open_process_out :
string -> Pervasives.out_channel
Same as
Unix.open_process_in , but redirect the standard input of the
command to a pipe. Data written to the returned output channel is sent to the
standard input of the command. Warning: writes on output channels are
buffered, hence be careful to call
Pervasives.flush at the right times
to ensure correct synchronization.
val open_process :
string -> Pervasives.in_channel *
Pervasives.out_channel
Same as
Unix.open_process_out , but redirects both the standard input and
standard output of the command to pipes connected to the two returned
channels. The input channel is connected to the output of the command, and the
output channel to the input of the command.
val open_process_full :
string -> string array ->
Pervasives.in_channel * Pervasives.out_channel * Pervasives.in_channel
Similar to
Unix.open_process , but the second argument specifies the
environment passed to the command. The result is a triple of channels
connected respectively to the standard output, standard input, and standard
error of the command.
val close_process_in :
Pervasives.in_channel -> process_status
Close channels opened by
Unix.open_process_in , wait for the associated
command to terminate, and return its termination status.
val close_process_out :
Pervasives.out_channel ->
process_status
Close channels opened by
Unix.open_process_out , wait for the associated
command to terminate, and return its termination status.
val close_process :
Pervasives.in_channel * Pervasives.out_channel
-> process_status
Close channels opened by
Unix.open_process , wait for the associated
command to terminate, and return its termination status.
val close_process_full :
Pervasives.in_channel *
Pervasives.out_channel * Pervasives.in_channel -> process_status
Close channels opened by
Unix.open_process_full , wait for the associated
command to terminate, and return its termination status.
=== Symbolic links ===
val symlink :
string -> string -> unit
symlink source dest creates the file
dest as a symbolic link to
the file
source .
val readlink :
string -> string
Read the contents of a link.
=== Polling ===
val select :
file_descr list -> file_descr list ->
file_descr list -> float -> file_descr list * file_descr list
* file_descr list
Wait until some input/output operations become possible on some channels. The
three list arguments are, respectively, a set of descriptors to check for
reading (first argument), for writing (second argument), or for exceptional
conditions (third argument). The fourth argument is the maximal timeout, in
seconds; a negative fourth argument means no timeout (unbounded wait). The
result is composed of three sets of descriptors: those ready for reading
(first component), ready for writing (second component), and over which an
exceptional condition is pending (third component).
=== Locking ===
type lock_command =
| F_ULOCK (* Unlock a region *)
| F_LOCK (* Lock a region for writing, and block if already locked *)
| F_TLOCK (* Lock a region for writing, or fail if already locked *)
| F_TEST (* Test a region for other process locks *)
| F_RLOCK (* Lock a region for reading, and block if already locked *)
| F_TRLOCK (* Lock a region for reading, or fail if already locked *)
Commands for
Unix.lockf .
val lockf :
file_descr -> lock_command -> int -> unit
lockf fd cmd size puts a lock on a region of the file opened as
fd
. The region starts at the current read/write position for
fd (as set
by
Unix.lseek ), and extends
size bytes forward if
size
is positive,
size bytes backwards if
size is negative, or to the
end of the file if
size is zero. A write lock prevents any other
process from acquiring a read or write lock on the region. A read lock
prevents any other process from acquiring a write lock on the region, but lets
other processes acquire read locks on it.
The
F_LOCK and
F_TLOCK commands attempts to put a write lock on
the specified region. The
F_RLOCK and
F_TRLOCK commands attempts
to put a read lock on the specified region. If one or several locks put by
another process prevent the current process from acquiring the lock,
F_LOCK and
F_RLOCK block until these locks are removed, while
F_TLOCK and
F_TRLOCK fail immediately with an exception. The
F_ULOCK removes whatever locks the current process has on the specified
region. Finally, the
F_TEST command tests whether a write lock can be
acquired on the specified region, without actually putting a lock. It returns
immediately if successful, or fails otherwise.
=== Signals Note: installation of signal handlers is performed
via the functions Sys.signal and Sys.set_signal. ===
val kill :
int -> int -> unit
kill pid sig sends signal number
sig to the process with id
pid .
type sigprocmask_command =
| SIG_SETMASK
| SIG_BLOCK
| SIG_UNBLOCK
val sigprocmask :
sigprocmask_command -> int list -> int
list
sigprocmask cmd sigs changes the set of blocked signals. If
cmd is
SIG_SETMASK , blocked signals are set to those in the list
sigs
. If
cmd is
SIG_BLOCK , the signals in
sigs are added to
the set of blocked signals. If
cmd is
SIG_UNBLOCK , the signals
in
sigs are removed from the set of blocked signals.
sigprocmask
returns the set of previously blocked signals.
val sigpending :
unit -> int list
Return the set of blocked signals that are currently pending.
val sigsuspend :
int list -> unit
sigsuspend sigs atomically sets the blocked signals to
sigs and
waits for a non-ignored, non-blocked signal to be delivered. On return, the
blocked signals are reset to their initial value.
val pause :
unit -> unit
Wait until a non-ignored, non-blocked signal is delivered.
=== Time functions ===
type process_times = {
tms_utime :
float ; (* User time for the process *)
tms_stime :
float ; (* System time for the process *)
tms_cutime :
float ; (* User time for the children processes *)
tms_cstime :
float ; (* System time for the children processes *)
}
The execution times (CPU times) of a process.
type tm = {
tm_sec :
int ; (* Seconds 0..60 *)
tm_min :
int ; (* Minutes 0..59 *)
tm_hour :
int ; (* Hours 0..23 *)
tm_mday :
int ; (* Day of month 1..31 *)
tm_mon :
int ; (* Month of year 0..11 *)
tm_year :
int ; (* Year - 1900 *)
tm_wday :
int ; (* Day of week (Sunday is 0) *)
tm_yday :
int ; (* Day of year 0..365 *)
tm_isdst :
bool ; (* Daylight time savings in effect *)
}
The type representing wallclock time and calendar date.
val time :
unit -> float
Return the current time since 00:00:00 GMT, Jan. 1, 1970, in seconds.
val gettimeofday :
unit -> float
Same as
Unix.time , but with resolution better than 1 second.
val gmtime :
float -> tm
Convert a time in seconds, as returned by
Unix.time , into a date and a
time. Assumes UTC (Coordinated Universal Time), also known as GMT.
val localtime :
float -> tm
Convert a time in seconds, as returned by
Unix.time , into a date and a
time. Assumes the local time zone.
val mktime :
tm -> float * tm
Convert a date and time, specified by the
tm argument, into a time in
seconds, as returned by
Unix.time . The
tm_isdst ,
tm_wday and
tm_yday fields of
tm are ignored. Also return
a normalized copy of the given
tm record, with the
tm_wday ,
tm_yday , and
tm_isdst fields recomputed from the other fields,
and the other fields normalized (so that, e.g., 40 October is changed into 9
November). The
tm argument is interpreted in the local time zone.
val alarm :
int -> int
Schedule a
SIGALRM signal after the given number of seconds.
val sleep :
int -> unit
Stop execution for the given number of seconds.
val times :
unit -> process_times
Return the execution times of the process.
val utimes :
string -> float -> float -> unit
Set the last access time (second arg) and last modification time (third arg) for
a file. Times are expressed in seconds from 00:00:00 GMT, Jan. 1, 1970. A time
of
0.0 is interpreted as the current time.
type interval_timer =
| ITIMER_REAL (* decrements in real time, and sends the signal
SIGALRM
when expired. *)
| ITIMER_VIRTUAL (* decrements in process virtual time, and sends
SIGVTALRM when expired. *)
| ITIMER_PROF (* (for profiling) decrements both when the process is running
and when the system is running on behalf of the process; it sends
SIGPROF when expired. *)
The three kinds of interval timers.
type interval_timer_status = {
it_interval :
float ; (* Period *)
it_value :
float ; (* Current value of the timer *)
}
The type describing the status of an interval timer
val getitimer :
interval_timer -> interval_timer_status
Return the current status of the given interval timer.
val setitimer :
interval_timer -> interval_timer_status
-> interval_timer_status
setitimer t s sets the interval timer
t and returns its previous
status. The
s argument is interpreted as follows:
s.it_value ,
if nonzero, is the time to the next timer expiration;
s.it_interval ,
if nonzero, specifies a value to be used in reloading it_value when the timer
expires. Setting
s.it_value to zero disable the timer. Setting
s.it_interval to zero causes the timer to be disabled after its next
expiration.
=== User id, group id ===
val getuid :
unit -> int
Return the user id of the user executing the process.
val geteuid :
unit -> int
Return the effective user id under which the process runs.
val setuid :
int -> unit
Set the real user id and effective user id for the process.
val getgid :
unit -> int
Return the group id of the user executing the process.
val getegid :
unit -> int
Return the effective group id under which the process runs.
val setgid :
int -> unit
Set the real group id and effective group id for the process.
val getgroups :
unit -> int array
Return the list of groups to which the user executing the process belongs.
val setgroups :
int array -> unit
setgroups groups sets the supplementary group IDs for the calling
process. Appropriate privileges are required.
val initgroups :
string -> int -> unit
initgroups user group initializes the group access list by reading the
group database /etc/group and using all groups of which
user is a
member. The additional group
group is also added to the list.
type passwd_entry = {
pw_name :
string ;
pw_passwd :
string ;
pw_uid :
int ;
pw_gid :
int ;
pw_gecos :
string ;
pw_dir :
string ;
pw_shell :
string ;
}
Structure of entries in the
passwd database.
type group_entry = {
gr_name :
string ;
gr_passwd :
string ;
gr_gid :
int ;
gr_mem :
string array ;
}
Structure of entries in the
groups database.
val getlogin :
unit -> string
Return the login name of the user executing the process.
val getpwnam :
string -> passwd_entry
Find an entry in
passwd with the given name, or raise
Not_found .
val getgrnam :
string -> group_entry
Find an entry in
group with the given name, or raise
Not_found .
val getpwuid :
int -> passwd_entry
Find an entry in
passwd with the given user id, or raise
Not_found
.
val getgrgid :
int -> group_entry
Find an entry in
group with the given group id, or raise
Not_found
.
=== Internet addresses ===
type inet_addr
The abstract type of Internet addresses.
val inet_addr_of_string :
string -> inet_addr
Conversion from the printable representation of an Internet address to its
internal representation. The argument string consists of 4 numbers separated
by periods (
XXX.YYY.ZZZ.TTT ) for IPv4 addresses, and up to 8 numbers
separated by colons for IPv6 addresses. Raise
Failure when given a
string that does not match these formats.
val string_of_inet_addr :
inet_addr -> string
Return the printable representation of the given Internet address. See
Unix.inet_addr_of_string for a description of the printable
representation.
val inet_addr_any :
inet_addr
A special IPv4 address, for use only with
bind , representing all the
Internet addresses that the host machine possesses.
val inet_addr_loopback :
inet_addr
A special IPv4 address representing the host machine (
127.0.0.1 ).
val inet6_addr_any :
inet_addr
A special IPv6 address, for use only with
bind , representing all the
Internet addresses that the host machine possesses.
val inet6_addr_loopback :
inet_addr
A special IPv6 address representing the host machine (
::1 ).
=== Sockets ===
type socket_domain =
| PF_UNIX (* Unix domain *)
| PF_INET (* Internet domain (IPv4) *)
| PF_INET6 (* Internet domain (IPv6) *)
The type of socket domains. Not all platforms support IPv6 sockets (type
PF_INET6 ).
type socket_type =
| SOCK_STREAM (* Stream socket *)
| SOCK_DGRAM (* Datagram socket *)
| SOCK_RAW (* Raw socket *)
| SOCK_SEQPACKET (* Sequenced packets socket *)
The type of socket kinds, specifying the semantics of communications.
type sockaddr =
| ADDR_UNIX
of string
| ADDR_INET
of inet_addr * int (* The type of socket
addresses.
ADDR_UNIX name is a socket address in the Unix domain;
name is a file name in the file system.
ADDR_INET(addr,port) is
a socket address in the Internet domain;
addr is the Internet address
of the machine, and
port is the port number. *)
val socket :
socket_domain -> socket_type -> int ->
file_descr
Create a new socket in the given domain, and with the given kind. The third
argument is the protocol type; 0 selects the default protocol for that kind of
sockets.
val domain_of_sockaddr :
sockaddr -> socket_domain
Return the socket domain adequate for the given socket address.
val socketpair :
socket_domain -> socket_type -> int
-> file_descr * file_descr
Create a pair of unnamed sockets, connected together.
val accept :
file_descr -> file_descr * sockaddr
Accept connections on the given socket. The returned descriptor is a socket
connected to the client; the returned address is the address of the connecting
client.
val bind :
file_descr -> sockaddr -> unit
Bind a socket to an address.
val connect :
file_descr -> sockaddr -> unit
Connect a socket to an address.
val listen :
file_descr -> int -> unit
Set up a socket for receiving connection requests. The integer argument is the
maximal number of pending requests.
type shutdown_command =
| SHUTDOWN_RECEIVE (* Close for receiving *)
| SHUTDOWN_SEND (* Close for sending *)
| SHUTDOWN_ALL (* Close both *)
The type of commands for
shutdown .
val shutdown :
file_descr -> shutdown_command -> unit
Shutdown a socket connection.
SHUTDOWN_SEND as second argument causes
reads on the other end of the connection to return an end-of-file condition.
SHUTDOWN_RECEIVE causes writes on the other end of the connection to
return a closed pipe condition (
SIGPIPE signal).
val getsockname :
file_descr -> sockaddr
Return the address of the given socket.
val getpeername :
file_descr -> sockaddr
Return the address of the host connected to the given socket.
type msg_flag =
| MSG_OOB
| MSG_DONTROUTE
| MSG_PEEK (* The flags for
Unix.recv ,
Unix.recvfrom ,
Unix.send and
Unix.sendto . *)
val recv :
file_descr -> string -> int -> int -> msg_flag
list -> int
Receive data from a connected socket.
val recvfrom :
file_descr -> string -> int -> int
-> msg_flag list -> int * sockaddr
Receive data from an unconnected socket.
val send :
file_descr -> string -> int -> int -> msg_flag
list -> int
Send data over a connected socket.
val sendto :
file_descr -> string -> int -> int ->
msg_flag list -> sockaddr -> int
Send data over an unconnected socket.
=== Socket options ===
type socket_bool_option =
| SO_DEBUG (* Record debugging information *)
| SO_BROADCAST (* Permit sending of broadcast messages *)
| SO_REUSEADDR (* Allow reuse of local addresses for bind *)
| SO_KEEPALIVE (* Keep connection active *)
| SO_DONTROUTE (* Bypass the standard routing algorithms *)
| SO_OOBINLINE (* Leave out-of-band data in line *)
| SO_ACCEPTCONN (* Report whether socket listening is enabled *)
| TCP_NODELAY (* Control the Nagle algorithm for TCP sockets *)
| IPV6_ONLY (* Forbid binding an IPv6 socket to an IPv4 address *)
The socket options that can be consulted with
Unix.getsockopt and
modified with
Unix.setsockopt . These options have a boolean (
true /
false ) value.
type socket_int_option =
| SO_SNDBUF (* Size of send buffer *)
| SO_RCVBUF (* Size of received buffer *)
| SO_ERROR (* Deprecated. Use
Unix.getsockopt_error instead. *)
| SO_TYPE (* Report the socket type *)
| SO_RCVLOWAT (* Minimum number of bytes to process for input operations *)
| SO_SNDLOWAT (* Minimum number of bytes to process for output operations *)
The socket options that can be consulted with
Unix.getsockopt_int and
modified with
Unix.setsockopt_int . These options have an integer
value.
type socket_optint_option =
| SO_LINGER (* Whether to linger on closed connections that have data present,
and for how long (in seconds) *)
The socket options that can be consulted with
Unix.getsockopt_optint and
modified with
Unix.setsockopt_optint . These options have a value of
type
int option , with
None meaning ``disabled''.
type socket_float_option =
| SO_RCVTIMEO (* Timeout for input operations *)
| SO_SNDTIMEO (* Timeout for output operations *)
The socket options that can be consulted with
Unix.getsockopt_float and
modified with
Unix.setsockopt_float . These options have a
floating-point value representing a time in seconds. The value 0 means
infinite timeout.
val getsockopt :
file_descr -> socket_bool_option -> bool
Return the current status of a boolean-valued option in the given socket.
val setsockopt :
file_descr -> socket_bool_option -> bool ->
unit
Set or clear a boolean-valued option in the given socket.
val getsockopt_int :
file_descr -> socket_int_option -> int
Same as
Unix.getsockopt for an integer-valued socket option.
val setsockopt_int :
file_descr -> socket_int_option -> int
-> unit
Same as
Unix.setsockopt for an integer-valued socket option.
val getsockopt_optint :
file_descr -> socket_optint_option ->
int option
Same as
Unix.getsockopt for a socket option whose value is an
int
option .
val setsockopt_optint :
file_descr -> socket_optint_option ->
int option -> unit
Same as
Unix.setsockopt for a socket option whose value is an
int
option .
val getsockopt_float :
file_descr -> socket_float_option ->
float
Same as
Unix.getsockopt for a socket option whose value is a
floating-point number.
val setsockopt_float :
file_descr -> socket_float_option ->
float -> unit
Same as
Unix.setsockopt for a socket option whose value is a
floating-point number.
val getsockopt_error :
file_descr -> error option
Return the error condition associated with the given socket, and clear it.
=== High-level network connection functions ===
val open_connection :
sockaddr -> Pervasives.in_channel *
Pervasives.out_channel
Connect to a server at the given address. Return a pair of buffered channels
connected to the server. Remember to call
Pervasives.flush on the
output channel at the right times to ensure correct synchronization.
val shutdown_connection :
Pervasives.in_channel -> unit
``Shut down'' a connection established with
Unix.open_connection ; that
is, transmit an end-of-file condition to the server reading on the other side
of the connection.
val establish_server :
(Pervasives.in_channel ->
Pervasives.out_channel -> unit) -> sockaddr -> unit
Establish a server on the given address. The function given as first argument is
called for each connection with two buffered channels connected to the client.
A new process is created for each connection. The function
Unix.establish_server never returns normally.
=== Host and protocol databases ===
type host_entry = {
h_name :
string ;
h_aliases :
string array ;
h_addrtype :
socket_domain ;
h_addr_list :
inet_addr array ;
}
Structure of entries in the
hosts database.
type protocol_entry = {
p_name :
string ;
p_aliases :
string array ;
p_proto :
int ;
}
Structure of entries in the
protocols database.
type service_entry = {
s_name :
string ;
s_aliases :
string array ;
s_port :
int ;
s_proto :
string ;
}
Structure of entries in the
services database.
val gethostname :
unit -> string
Return the name of the local host.
val gethostbyname :
string -> host_entry
Find an entry in
hosts with the given name, or raise
Not_found .
val gethostbyaddr :
inet_addr -> host_entry
Find an entry in
hosts with the given address, or raise
Not_found
.
val getprotobyname :
string -> protocol_entry
Find an entry in
protocols with the given name, or raise
Not_found
.
val getprotobynumber :
int -> protocol_entry
Find an entry in
protocols with the given protocol number, or raise
Not_found .
val getservbyname :
string -> string -> service_entry
Find an entry in
services with the given name, or raise
Not_found
.
val getservbyport :
int -> string -> service_entry
Find an entry in
services with the given service number, or raise
Not_found .
type addr_info = {
ai_family :
socket_domain ; (* Socket domain *)
ai_socktype :
socket_type ; (* Socket type *)
ai_protocol :
int ; (* Socket protocol number *)
ai_addr :
sockaddr ; (* Address *)
ai_canonname :
string ; (* Canonical host name *)
}
Address information returned by
Unix.getaddrinfo .
type getaddrinfo_option =
| AI_FAMILY
of socket_domain (* Impose the given socket
domain *)
| AI_SOCKTYPE
of socket_type (* Impose the given socket
type *)
| AI_PROTOCOL
of int (* Impose the given protocol *)
| AI_NUMERICHOST (* Do not call name resolver, expect numeric IP address *)
| AI_CANONNAME (* Fill the
ai_canonname field of the result *)
| AI_PASSIVE (* Set address to ``any'' address for use with
Unix.bind
*)
Options to
Unix.getaddrinfo .
val getaddrinfo :
string -> string -> getaddrinfo_option list
-> addr_info list
getaddrinfo host service opts returns a list of
Unix.addr_info
records describing socket parameters and addresses suitable for communicating
with the given host and service. The empty list is returned if the host or
service names are unknown, or the constraints expressed in
opts cannot
be satisfied.
host is either a host name or the string representation of an IP address.
host can be given as the empty string; in this case, the ``any''
address or the ``loopback'' address are used, depending whether
opts
contains
AI_PASSIVE .
service is either a service name or the
string representation of a port number.
service can be given as the
empty string; in this case, the port field of the returned addresses is set to
0.
opts is a possibly empty list of options that allows the caller to
force a particular socket domain (e.g. IPv6 only or IPv4 only) or a particular
socket type (e.g. TCP only or UDP only).
type name_info = {
ni_hostname :
string ; (* Name or IP address of host *)
ni_service :
string ;
}
Name of service or port number
=== Host and service information returned by Unix.getnameinfo. ===
type getnameinfo_option =
| NI_NOFQDN (* Do not qualify local host names *)
| NI_NUMERICHOST (* Always return host as IP address *)
| NI_NAMEREQD (* Fail if host name cannot be determined *)
| NI_NUMERICSERV (* Always return service as port number *)
| NI_DGRAM (* Consider the service as UDP-based instead of the default TCP *)
Options to
Unix.getnameinfo .
val getnameinfo :
sockaddr -> getnameinfo_option list ->
name_info
getnameinfo addr opts returns the host name and service name
corresponding to the socket address
addr .
opts is a possibly
empty list of options that governs how these names are obtained. Raise
Not_found if an error occurs.
=== Terminal interface ===
=== The following functions implement the POSIX standard terminal
interface. They provide control over asynchronous communication ports
and pseudo-terminals. Refer to the termios man page for a complete
description. ===
type terminal_io = {
mutable c_ignbrk :
bool ; (* Ignore the break condition. *)
mutable c_brkint :
bool ; (* Signal interrupt on break condition.
*)
mutable c_ignpar :
bool ; (* Ignore characters with parity errors.
*)
mutable c_parmrk :
bool ; (* Mark parity errors. *)
mutable c_inpck :
bool ; (* Enable parity check on input. *)
mutable c_istrip :
bool ; (* Strip 8th bit on input characters. *)
mutable c_inlcr :
bool ; (* Map NL to CR on input. *)
mutable c_igncr :
bool ; (* Ignore CR on input. *)
mutable c_icrnl :
bool ; (* Map CR to NL on input. *)
mutable c_ixon :
bool ; (* Recognize XON/XOFF characters on input.
*)
mutable c_ixoff :
bool ; (* Emit XON/XOFF chars to control input
flow. *)
mutable c_opost :
bool ; (* Enable output processing. *)
mutable c_obaud :
int ; (* Output baud rate (0 means close
connection). *)
mutable c_ibaud :
int ; (* Input baud rate. *)
mutable c_csize :
int ; (* Number of bits per character (5-8). *)
mutable c_cstopb :
int ; (* Number of stop bits (1-2). *)
mutable c_cread :
bool ; (* Reception is enabled. *)
mutable c_parenb :
bool ; (* Enable parity generation and
detection. *)
mutable c_parodd :
bool ; (* Specify odd parity instead of even.
*)
mutable c_hupcl :
bool ; (* Hang up on last close. *)
mutable c_clocal :
bool ; (* Ignore modem status lines. *)
mutable c_isig :
bool ; (* Generate signal on INTR, QUIT, SUSP. *)
mutable c_icanon :
bool ; (* Enable canonical processing (line
buffering and editing) *)
mutable c_noflsh :
bool ; (* Disable flush after INTR, QUIT, SUSP.
*)
mutable c_echo :
bool ; (* Echo input characters. *)
mutable c_echoe :
bool ; (* Echo ERASE (to erase previous
character). *)
mutable c_echok :
bool ; (* Echo KILL (to erase the current line).
*)
mutable c_echonl :
bool ; (* Echo NL even if c_echo is not set. *)
mutable c_vintr :
char ; (* Interrupt character (usually ctrl-C).
*)
mutable c_vquit :
char ; (* Quit character (usually ctrl-\). *)
mutable c_verase :
char ; (* Erase character (usually DEL or
ctrl-H). *)
mutable c_vkill :
char ; (* Kill line character (usually ctrl-U).
*)
mutable c_veof :
char ; (* End-of-file character (usually ctrl-D).
*)
mutable c_veol :
char ; (* Alternate end-of-line char. (usually
none). *)
mutable c_vmin :
int ; (* Minimum number of characters to read
before the read request is satisfied. *)
mutable c_vtime :
int ; (* Maximum read wait (in 0.1s units). *)
mutable c_vstart :
char ; (* Start character (usually ctrl-Q). *)
mutable c_vstop :
char ; (* Stop character (usually ctrl-S). *)
}
val tcgetattr :
file_descr -> terminal_io
Return the status of the terminal referred to by the given file descriptor.
type setattr_when =
| TCSANOW
| TCSADRAIN
| TCSAFLUSH
val tcsetattr :
file_descr -> setattr_when -> terminal_io ->
unit
Set the status of the terminal referred to by the given file descriptor. The
second argument indicates when the status change takes place: immediately (
TCSANOW ), when all pending output has been transmitted (
TCSADRAIN ), or after flushing all input that has been received but not
read (
TCSAFLUSH ).
TCSADRAIN is recommended when changing the
output parameters;
TCSAFLUSH , when changing the input parameters.
val tcsendbreak :
file_descr -> int -> unit
Send a break condition on the given file descriptor. The second argument is the
duration of the break, in 0.1s units; 0 means standard duration (0.25s).
val tcdrain :
file_descr -> unit
Waits until all output written on the given file descriptor has been
transmitted.
type flush_queue =
| TCIFLUSH
| TCOFLUSH
| TCIOFLUSH
val tcflush :
file_descr -> flush_queue -> unit
Discard data written on the given file descriptor but not yet transmitted, or
data received but not yet read, depending on the second argument:
TCIFLUSH flushes data received but not read,
TCOFLUSH flushes
data written but not transmitted, and
TCIOFLUSH flushes both.
type flow_action =
| TCOOFF
| TCOON
| TCIOFF
| TCION
val tcflow :
file_descr -> flow_action -> unit
Suspend or restart reception or transmission of data on the given file
descriptor, depending on the second argument:
TCOOFF suspends output,
TCOON restarts output,
TCIOFF transmits a STOP character to
suspend input, and
TCION transmits a START character to restart input.
val setsid :
unit -> int
Put the calling process in a new session and detach it from its controlling
terminal.