The Standard ML Basis Library

The `Posix.ProcEnv` structure

Synopsis

signature POSIX_PROC_ENV structure ProcEnv : POSIX_PROC_ENV

The structure Posix.ProcEnv specifies functions, as described in Section 4 of the POSIX standard 1003.1,1996[CITE], which provide primitive POSIX access to the process environment.

Interface

eqtype pid eqtype uid eqtype gid eqtype file_desc val uidToWord : uid -> SysWord.word val wordToUid : SysWord.word -> uid val gidToWord : gid -> SysWord.word val wordToGid : SysWord.word -> gid val getpid : unit -> pid val getppid : unit -> pid val getuid : unit -> uid val geteuid : unit -> uid val getgid : unit -> gid val getegid : unit -> gid val setuid : uid -> unit val setgid : gid -> unit val getgroups : unit -> gid list val getlogin : unit -> string val getpgrp : unit -> pid val setsid : unit -> pid val setpgid : {pid : pid option, pgid : pid option} -> unit val uname : unit -> (string * string) list val time : unit -> Time.time val times : unit -> { elapsed : Time.time, utime : Time.time, stime : Time.time, cutime : Time.time, cstime : Time.time } val getenv : string -> string option val environ : unit -> string list val ctermid : unit -> string val ttyname : file_desc -> string val isatty : file_desc -> bool val sysconf : string -> SysWord.word

Description

eqtype pid

A process ID, used as an identifier for an operating system process.

eqtype uid

User identifier.

eqtype gid

Group identifier.

eqtype file_desc

Open file descriptor.

val uidToWord : uid -> SysWord.word val wordToUid : SysWord.word -> uid

These functions convert between an abstract user ID and an underlying unique unsigned integer. Note that wordToUid does not ensure that it returns a valid uid.

val gidToWord : gid -> SysWord.word val wordToGid : SysWord.word -> gid

These convert between an abstract group ID and an underlying unique unsigned integer. Note that wordToGid does not ensure that it returns a valid gid.

val getpid : unit -> pid val getppid : unit -> pid

The process ID and the parent process ID, respectively, of the calling process.

val getuid : unit -> uid val geteuid : unit -> uid

The real and effective user IDs, respectively, of the calling process.

val getgid : unit -> gid val getegid : unit -> gid

The real and effective group IDs, respectively, of the calling process.

setuid u

sets the real user ID and effective user ID to u.

setgid g

sets the real group ID and effective group ID to g.

val getgroups : unit -> gid list

The list of supplementary group IDs of the calling process.

val getlogin : unit -> string

The user name associated with the calling process, i.e., the login name associated with the calling process.

val getpgrp : unit -> pid

The process group ID of the calling process.

val setsid : unit -> pid

This function creates a new session if the calling process is not a process group leader, and returns the process group ID of the calling process.

setpgid (SOME pid, SOME pgid)

setpgid (NONE, SOME pgid)

setpgid (SOME pid, NONE)

setpgid (NONE, NONE)

The first (second) usage sets the process group ID of the process with process ID pid (of the calling process, respectively) to pgid. In the third (fourth) usage, the process with process ID pid (the calling process, respectively) becomes a process group leader.

val uname : unit -> (string * string) list

A list of name-value pairs including, at least, the names: "sysname", "nodename", "release", "version", and "machine". (A POSIX implementation may provide additional values beyond this set.) The respective values are strings that describe the named system component.

val time : unit -> Time.time

The elapsed wall time since the Epoch.

val times : unit -> { elapsed : Time.time, utime : Time.time, stime : Time.time, cutime : Time.time, cstime : Time.time }

A record containing the wall time (elapsed), user time (utime), system time (stime), user CPU time of terminated child processes (cutime), and system CPU time of terminated child processes (cstime), for the calling process.

getenv name

searches the environment list for a string of the form name=value and returns SOME(value) if name is present; it returns NONE if name is not present. This is equivalent to OS.Process.getEnv.

val environ : unit -> string list

The environment of the calling process as a list of strings.

val ctermid : unit -> string

A string that represents the pathname of the controlling terminal for the calling process.

ttyname fd

produces a string that represents the pathname of the terminal associated with file descriptor fd. It raises OS.SysErr if fd does not denote a valid terminal device.

isatty fd

returns true if fd is a valid file descriptor associated with a terminal. Note that isatty will return false if fd is a bad file descriptor.

sysconf s

returns the integer value for the POSIX configurable system variable s. It raises OS.SysErr if s does not denote a supported POSIX system variable.

The properties required by POSIX are described below. This list is a minimal set required for POSIX compliance, and an implementation may extend it with additional properties.

"ARG_MAX": Maximum length of arguments, in bytes, for the functions Posix.Process.exec, Posix.Process.exece, and Posix.Process.execp. This also applies to environment data.
"CHILD_MAX": Maximum number of concurrent processes associated with a real user ID.
"CLK_TCK": Number of clock ticks per second.
"NGROUPS_MAX": Maximum number of supplementary group IDs associated with a process, in addition to the effective group ID.
"OPEN_MAX": Maximum number of files that one process can have open concurrently.
"STREAM_MAX": Maximum number of streams that one process can have open concurrently.
"TZNAME_MAX": Maximum number bytes allowed for a time zone name.
"JOB_CONTROL": Non-zero if the implementation supports job control.
"SAVED_IDS": Non-zero if each process has a saved set-user-ID and and saved set-group-ID.
"VERSION": A version number.

Consult Section 4.8 of POSIX standard 1003.1,1996 [CITE] for additional information. Note that a property in SML has the same name as the property in C, but without the prefix "_SC_".

The Standard ML Basis Library

The Posix.ProcEnv structure

Synopsis

Interface

Description

See Also

The `Posix.ProcEnv` structure