This module contains part of a Fortran API to functions detailed in ISO/IEC 9945-1:1990 Portable Operating System Interface (POSIX) - Part 1: System Application Program Interface (API) [C Language].
The functions in this module are from Section 4: Process Environment, plus
gethostname from 4.3BSD.
Error handling is described in F90_UNIX_ERRNO.
Note that for procedures with an optional ERRNO argument, if an error
occurs and ERRNO is not present, the program will be terminated.
All the procedures in this module are generic; some are also specific (this may change in a future release).
INTEGER(int32),PARAMETER :: clock_tick_kindThe integer kind used for clock ticks (see
TIMES).
INTEGER(int32),PARAMETER :: id_kindInteger kind for representing IDs; that is, users (uids), groups (gids), process groups (pgids) and processes (pids).
INTEGER(int32),PARAMETER :: long_kindThe integer kind corresponding to the C type ‘long’. This is not actually used in this module, but is suitable for use when declaring a variable to receive a value from
SYSCONF.
INTEGER(int32),PARAMETER :: sc_stdin_unit, sc_stdout_unit, sc_stderr_unit,
sc_arg_max, sc_child_max, sc_clk_tck, sc_job_control, sc_open_max,
sc_ngroups_max, sc_saved_ids, sc_stream_max, sc_tzname_max, sc_version
Values used as arguments to SYSCONF.
The following table describes the returned information from SYSCONF,
this is not the value of the SC_* constant.
SC_STDIN_UNITREAD *,...); this is the
same value as INPUT_UNIT in the standard intrinsic module
ISO_FORTRAN_ENV.
SC_STDOUT_UNITPRINT,
WRITE(*,...)); this is the same value as OUTPUT_UNIT in
the standard intrinsic module ISO_FORTRAN_ENV.
SC_STDERR_UNITERROR_UNIT in the standard intrinsic module ISO_FORTRAN_ENV.
SC_ARG_MAXEXEC functions, in bytes, including
environment data.
SC_CHILD_MAXSC_CLK_TCKCLK_TCK function).
SC_JOB_CONTROLSC_NGROUPS_MAXSC_OPEN_MAXSC_SAVED_IDSSC_STREAM_MAXSC_TZNAME_MAXSC_VERSION
INTEGER(int32),PARAMETER :: time_kindThe integer kind used for holding date/time values (see
TIME).
TYPE tms
INTEGER(clock_tick_kind) utime, stime, cutime, cstime
END TYPE
Derived type holding CPU usage time in clock ticks. UTIME and
STIME contain CPU time information for a process, CUTIME and
CSTIME contain CPU time information for its terminated child processes.
In each case this is divided into user time (UTIME, CUTIME) and
system time (STIME, CSTIME).
TYPE utsname
CHARACTER(...) sysname, nodename, release, version, machine
END TYPE
Derived type holding data returned by UNAME.
Note that the character length of each component is fixed, but may be
different on different systems.
The values in these components are blank-padded (if short) or truncated
(if long).
For further information see ISO/IEC 9945-1:1990.
PURE INTEGER(KIND=clock_tick_kind) FUNCTION clk_tck()Returns the number of clock ticks in one second of CPU time (see
TIMES).
PURE SUBROUTINE ctermid(s,lens)
CHARACTER(*),OPTIONAL,INTENT(OUT) :: s
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lens
If present, S is set to the filename of the controlling terminal.
If present, LENS is set to the length of the filename of the controlling
terminal.
If S is longer than the filename of the controlling terminal it is
padded with blanks; if S is shorter it is truncated — it is the user's
responsibility to check the value of LENS to detect such truncation.
If the filename of the controlling terminal cannot be determined for any
reason LENS (if present) will be set to zero and S (if present)
will be blank.
SUBROUTINE getarg(k,arg,lenarg,errno)
INTEGER(*),INTENT(IN) :: k
CHARACTER(*),OPTIONAL,INTENT(OUT) :: arg
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lenarg
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Accesses command-line argument number K, where argument zero is the
program name.
If ARG is present, it receives the argument text (blank-padded or
truncated as appropriate if the length of the argument differs from that of
ARG).
If LENARG is present, it receives the length of the argument.
If ERRNO is present, it receives the error status.
Note that if K is less than zero or greater than the number of arguments
(returned by IARGC) error EINVAL (see F90_UNIX_ERRNO) is
raised.
This procedure is very similar to the standard intrinsic procedure
GET_COMMAND_ARGUMENT.
PURE INTEGER(id_kind) FUNCTION getegid()Returns the effective group number of the calling process.
SUBROUTINE getenv(name,value,lenvalue,errno)
CHARACTER(*),INTENT(IN) :: name
CHARACTER(*),OPTIONAL,INTENT(OUT) :: value
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lenvalue
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Accesses the environment variable named by NAME.
If VALUE is present, it receives the text value of the variable
(blank-padded or truncated as appropriate if the length of the value differs
from that of VALUE).
If LENVALUE is present, it receives the length of the value.
If ERRNO is present, it receives the error status.
If there is no such variable, error EINVAL (see F90_UNIX_ERRNO)
is raised.
Other possible errors include ENOMEM.
PURE INTEGER(id_kind) FUNCTION geteuid()Returns the effective user number of the calling process.
PURE INTEGER(id_kind) FUNCTION getgid()Returns the group number of the calling process.
SUBROUTINE getgroups(grouplist,ngroups,errno)
INTEGER(id_kind),OPTIONAL,INTENT(OUT) :: grouplist(:)
INTEGER(int32),OPTIONAL,INTENT(OUT) :: ngroups
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Retrieves supplementary group number information for the calling process.
If GROUPLIST is present, it is filled with the supplementary group
numbers.
If NGROUPS is present, it receives the number of supplementary group
numbers.
If ERRNO is present, it receives the error status.
If GROUPLIST is present but too small to contain the complete list of
supplementary group numbers, error EINVAL (see F90_UNIX_ERRNO) is
raised.
The maximum number of supplementary group numbers can be found using
SYSCONF (enquiry SC_NGROUPS_MAX); alternatively,
‘CALL GETGROUPS(NGROUPS=N)’ will reliably return the actual
number in use.
PURE SUBROUTINE gethostname(name,lenname)
CHARACTER(*),OPTIONAL,INTENT(OUT) :: name
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lenname
This provides the functionality of 4.3BSD's gethostname.
If NAME is present it receives the text of the standard host name for the
current processor, blank-padded or truncated if appropriate.
If LENNAME is present it receives the length of the host name.
If no host name is available LENNAME will be zero.
PURE SUBROUTINE getlogin(s,lens)
CHARACTER(*),OPTIONAL,INTENT(OUT) :: s
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lens
Accesses the user name (login name) associated with the calling process.
If S is present, it receives the text of the name (blank-padded or
truncated as appropriate if the length of the login name differs from that of
S).
If LENS is present, it receives the length of the login name.
PURE INTEGER(id_kind) FUNCTION getpgrp()Returns the process group number of the calling process.
PURE INTEGER(id_kind) FUNCTION getpid()Returns the process number of the calling process.
PURE INTEGER(id_kind) FUNCTION getppid()Returns the process number of the parent of the calling process.
PURE INTEGER(id_kind) FUNCTION getuid()Returns the user number of the calling process.
PURE INTEGER(int32) FUNCTION iargc()Returns the number of command-line arguments; this is the same value as the intrinsic function
COMMAND_ARGUMENT_COUNT, except that it returns -1 if
even the program name is unavailable (the intrinsic function erroneously
returns the same value, 0, whether the program name is available or not).
SUBROUTINE isatty(lunit,answer,errno)
INTEGER(*),INTENT(IN) :: lunit
LOGICAL(*),INTENT(OUT) :: answer
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
ANSWER receives the value .TRUE. if and only if the logical unit
identified by LUNIT is connected to a terminal.
If LUNIT is not a valid unit number or is not connected to any file,
error EBADF (see F90_UNIX_ERRNO) is raised.
SUBROUTINE setgid(gid,errno)
INTEGER(*),INTENT(IN) :: gid
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Sets the group number of the calling process to GID.
For full details refer to section 4.2.2 of ISO/IEC 9945-1:1990.
If GID is not a valid group number, error EINVAL (see
F90_UNIX_ERRNO) is raised.
If the process is not allowed to set the group number to GID,
error EPERM is raised.
SUBROUTINE setpgid(pid,pgid,errno)
INTEGER(*),INTENT(IN) :: pid, pgid
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Sets the process group number of process PID (or, if PID is zero,
the calling process) to PGID.
For full details refer to section 4.3.3 of ISO/IEC 9945-1:1990.
Possible errors include EACCES, EINVAL, ENOSYS,
EPERM, ESRCH (see F90_UNIX_ERRNO).
SUBROUTINE setsid(sid,errno)
INTEGER(id_kind),OPTIONAL,INTENT(OUT) :: sid
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Creates a session and sets the process group number of the calling process.
For full details refer to section 4.3.2 of ISO/IEC 9945-1:1990.
If SID is present it receives the new session id (equal to the process
id); if an error occurs it receives -1.
Possible errors include EPERM (see F90_UNIX_ERRNO).
SUBROUTINE setuid(uid,errno)
INTEGER(*),INTENT(IN) :: uid
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Sets the user number of the calling process to UID.
For full details refer to section 4.2.2 of ISO/IEC 9945-1:1990.
If UID is not a valid group number, error EINVAL (see
F90_UNIX_ERRNO) is raised.
If the process is not allowed to set the user number to UID, error
EPERM is raised.
SUBROUTINE sysconf(name,val,errno)
INTEGER(*),INTENT(IN) :: name
INTEGER(*),INTENT(OUT) :: val
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Returns the value of a system configuration variable.
The variables are named by integer PARAMETERs defined in this module, and are
described in the Parameters section.
If NAME is not a valid configuration variable name, error EINVAL
(see F90_UNIX_ERRNO) is raised.
If VAL is too small an integer kind to contain the result,
error ERANGE is raised; kind LONG_KIND is guaranteed to be big
enough for all values.
SUBROUTINE time(itime,errno)
INTEGER(time_kind),INTENT(OUT) :: itime
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
ITIME receives the operating system date/time in seconds since the Epoch.
INTEGER(KIND=clock_tick_kind) FUNCTION times(buffer)
TYPE(tms),INTENT(OUT) :: buffer
This function returns the elapsed real time in clock ticks since an arbitrary
point in the past, or -1 if the function is unavailable.
BUFFER is filled in with CPU time information for the calling process
and any terminated child processes.
If this function returns zero the values in BUFFER will still be correct
but the elapsed-time timer was not available.
SUBROUTINE ttyname(lunit,s,lens,errno)
INTEGER(*),INTENT(IN) :: lunit
CHARACTER(*),OPTIONAL,INTENT(OUT) :: s
INTEGER(int32),OPTIONAL,INTENT(OUT) :: lens
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Accesses the name of the terminal connected to the logical unit identified by
LUNIT.
If S is present, it receives the text of the terminal name (blank-padded
or truncated as appropriate, if the length of the terminal name differs from
that of S).
If LENS is present, it receives the length of the terminal name.
If ERRNO is present, it receives the error status.
If LUNIT is not a valid logical unit number, or is not connected, error
EBADF (see F90_UNIX_ERRNO) is raised; otherwise, if the function
is not available, ENOSYS is raised, or if LUNIT is not connected
to a terminal, error ENOTTY is raised.
SUBROUTINE uname(name,errno)
TYPE(UTSNAME),INTENT(OUT) :: name
INTEGER(error_kind),OPTIONAL,INTENT(OUT) :: errno
Returns information about the operating system in NAME.