Developer Guide and Reference

ID 767251
Date 10/31/2024
Public
Document Table of Contents

PXFSYSCONF

POSIX Subroutine: Gets values for system limits or options.

Module

USE IFPOSIX

CALL PXFSYSCONF (name,ival,ierror)

name

(Input) INTEGER(4). The system option you want information about.

ival

(Output) INTEGER(4). The returned value.

ierror

(Output) INTEGER(4). The error status.

If successful, ierror is set to zero; otherwise, an error code.

PXFSYSCONF lets you determine values for system limits or system options at runtime.

The value for name can be any of the following constants:

Constant

Description

_SC_ARG_MAX1

Indicates the maximum length of the arguments to the PXFEXEC family of routines.

_SC_CHILD_MAX1

Indicates the number of simultaneous processes per user ID.

_SC_CLK_TCK

Indicates the number of clock ticks per second.

_SC_STREAM_MAX2

Indicates the maximum number of streams that a process can have open at any time.

_SC_TZNAME_MAX

Indicates the maximum number of bytes in a timezone name.

_SC_OPEN_MAX

Indicates the maximum number of files that a process can have open at any time.

_SC_JOB_CONTROL1

Indicates whether POSIX-style job control is supported.

_SC_SAVED_IDS1

Indicates whether a process has a saved set-user-ID and a saved set-group-ID.

_SC_VERSION1

Indicates the year and month the POSIX.1 standard was approved in the format YYYYMML; the value 199009L indicates the most recent revision, 1990.

_SC_BC_BASE_MAX1

Indicates the maximum obase value accepted by the bc(1) utility.

_SC_BC_DIM_MAX1

Indicates the maximum value of elements that bc(1) permits in an array.

_SC_BC_SCALE_MAX1

Indicates the maximum scale value allowed by bc(1).

_SC_BC_STRING_MAX1

Indicates the maximum length of a string accepted by bc(1).

_SC_COLL_WEIGHTS_MAX1

Indicates the maximum numbers of weights that can be assigned to an entry of the LC_COLLATE order keyword in the locale definition file.

_SC_EXPR_NEST_MAX1,3

Indicates the maximum number of expressions that can be nested within parentheses by expr(1).

_SC_LINE_MAX1

Indicates the maximum length of a utility's input line length, either from standard input or from a file. This includes the length for a trailing newline.

_SC_RE_DUP_MAX1

Indicates the maximum number of repeated occurrences of a regular expression when the interval notation \{m,n\} is used.

_SC_2_VERSION1

Indicates the version of the POSIX.2 standard; it is in the format YYYYMML.

_SC_2_DEV1

Indicates whether the POSIX.2 C language development facilities are supported.

_SC_2_FORT_DEV1

Indicates whether the POSIX.2 FORTRAN language development utilities are supported.

_SC_2_FORT_RUN1

Indicates whether the POSIX.2 FORTRAN runtime utilities are supported.

_SC_2_LOCALEDEF1

Indicates whether the POSIX.2 creation of locates via localedef(1) is supported.

_SC_2_SW_DEV1

Indicates whether the POSIX.2 software development utilities option is supported.

_SC_PAGESIZE (or _SC_PAGE_SIZE)

Indicates the size of a page (in bytes).

_SC_PHYS_PAGES4

Indicates the number of pages of physical memory. Note that it is possible for the product of this value and the value of _SC_PAGE_SIZE to overflow.

_SC_AVPHYS_PAGES4

Indicates the number of currently available pages of physical memory.

1Linux

2The corresponding POSIX macro is STREAM_MAX.

3The corresponding POSIX macro is EXPR_NEST_MAX.

4Linux and Windows

The corresponding macros are defined in <bits/confname.h> on Linux* systems. The values for argument name can be obtained by using PXFCONST or IPXFCONST when passing the string names of predefined macros in the appropriate .h file.

See Also