getconf - Displays system configuration variable values
getconf [-v specification] system_var
getconf [-v specification] path_var pathname
Interfaces documented on this reference page conform to
industry standards as follows:
getconf: XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
Indicates a specification and version for which configuration
variables are to be determined. If this option is
not specified, the values returned will correspond to an
implementation default XBS5-conforming compilation environment.
The specification can be one of the following symbolic
constants:
XBS5_ILP32_OFF32
XBS5_ILP32_OFFBIG
XBS5_LP64_OFF64
XBS5_LPBIG_OFFBIG
These four constants have corresponding system
standards configuration variables. The names are
the same except for a leading underscore in the
name of the configuration variable; for example,
the specification constant XBS5_ILP32_OFF32 corresponds
to the configuration variable
_XBS5_ILP32_OFF32.
If a getconf command is issued with one of these
configuration variables (for example,
_XBS5_LPBIG_OFFBIG) and does not return -1 or
"undefined", then a following getconf command with
a -v specification of XBS5_LPBIG_OFFBIG will determine
values for configuration variables corresponding
to the XBS5_LPBIG_OFFBIG compilation environment.
For example:
%sh $ outstr=`getconf _XBS5_LPBIG_OFFBIG` $ if
["$outstr"!="-1"] && ["$outstr"!="undefined"] >
then > cvars=`getconf -v XBS5_LPBIG_OFFBIG
XVS5_LPBIG_OFFBIG_id` > fi
The id in the system-wide configuration variable
identifies which configuration variables are to be
returned. See the description of XBS5_* variables
under the heading "System Standards Configuration
Variables" for details about the id suffix.
Name of a symbolic constant. (The symbolic constant names
are listed in the DESCRIPTION section under the heading
"Specification Constants".) Name of a system-wide configuration
variable. (These variable names are listed in the
DESCRIPTION section under the headings "System-Wide Configuration
Variables" and "System Standards Configuration
Variables".) Name of a system path-configuration variable.
(These variable names are listed in the DESCRIPTION
section under the heading "System Path Configuration Variables".)
A path name for the path_var variable.
In the system_var synopsis form, the getconf utility
writes, to the standard output, the value of the variable
specified in the system_var operand.
In the path_var synopsis form, the getconf utility writes,
to the standard output, the value of the variable specified
by the path_var operand for the path specified by the
pathname operand.
In both cases, the value reflects conditions in the current
operating environment.
The system_var argument specifies system-wide configuration
variables whose values are valid throughout the system.
There are two kinds of system-wide configuration values:
System-wide configuration variables System standards
configuration variables
The path_var argument specifies system path-configuration
variables whose values contain information about paths and
the path structure in the system.
Specification Variables [Toc] [Back]
Specifications return the value -1 or "undefined" if the
implementation of the standard in the system does not support
the configuration defined by the specification and a
value other than -1 if the implementation does support the
configuration. If these are undefined, the sysconf() function
can be used to determine whether the configuration is
provided for a particular invocation of the application.
This symbolic constant specifies that the implementation
is to provide a C-language compilation environment with
32-bit int, long, pointer, and off_t types. This symbolic
constant specifies that the implementation is to provide a
C-language compilation environment with 32-bit int, long,
and pointer types and an off_t type using at least 64
bits. This symbolic constant specifies that the implementation
is to provide a C-language compilation environment
with a 32-bit int type and 64-bit long, pointer, and off_t
types. This symbolic constant specifies that the implementation
is to provide a C-language compilation environment
with an int type using at least 32 bits and long,
pointer, and off_t types using at least 64 bits.
System-Wide Configuration Variables [Toc] [Back]
System-wide configuration variables contain the minimum
values met throughout all portions of the system. The following
list defines the system-wide configuration variables
used with the getconf command: The maximum length,
in bytes, of the arguments for one of the exec functions,
including environment data. [XPG4-UNIX] The maximum number
of functions that can be registered with atexit() per
process. The maximum value allowed for the obase variable
with the bc command. The maximum number of elements permitted
in an array by the bc command. The maximum value
allowed for the scale variable with the bc command. The
maximum length of string constants accepted by the bc command.
The maximum number of bytes in a character class
name. Number of bits in a type of char. The maximum
value of a type char. The minimum value of a type char.
The maximum number of simultaneous processes for each real
user ID. The number of clock ticks per second. The value
of CLK_TCK may be variable, and it should not be assumed
that CLK_TCK is a compile-time constant. The maximum number
of weights that can be assigned to an entry in the
LC_COLLATE locale-dependent information in a locale-definition
file. A value for the PATH environment variable
that finds all standard utilities. [Tru64 UNIX] The maximum
number of data keys that may be created per process.
The maximum number of expressions that can be nested
within parentheses by the expr command. The maximum value
of an int. The minimum value of an int. The maximum
length, in bytes, of a command's input line (either standard
input or another file) when the utility is described
as processing text files. The length includes room for the
trailing newline character. Number of bits in a long int.
The maximum value of a long int. The minimum value of a
long int. The maximum number of bytes in a character for
any supported locale. The maximum number of simultaneous
supplementary group IDs for each process. The maximum
value of digit in calls to the printf() and scanf() functions.
The maximum number of bytes in a LANG name. The
maximum message number. [Tru64 UNIX] The maximum number
of bytes in an N-to-1 collation mapping. The maximum set
number. The maximum number of bytes in a message string.
Default process priority. The maximum number of files
that one process can have open at one time.
[XPG4-UNIX] The page size granularity for memory regions.
[Tru64 UNIX] The maximum number of characters returned by
getpass() (not including terminating null). A value for
the PATH environment variable that finds all standard
utilities. [Tru64 UNIX] The official name of the
installed operating system product. The maximum number of
repeated occurrences of a regular expression permitted
when using the interval-notation parameters, such as the m
and n parameters with the ed command. The maximum value
of a type signed char. The minimum value of a type signed
char. The maximum value of a type short. The minimum
value of a type short. The maximum value that can be
stored in an object of type ssize_t. The number of
streams that one process can have open at one time.
[Tru64 UNIX] The official system banner. The banner typically
consists of the vendor name followed by the product
name. [Tru64 UNIX] The product version information. The
minimum number of unique path names generated by tmpnam().
Maximum number of times an application can call tmpnam()
reliably. The maximum number of bytes supported for the
name of a time zone (not the length of the TZ environmental
variable). The maximum value of a type unsigned char.
The maximum value of a type unsigned int. The maximum
value of a type unsigned long int. The maximum value of a
type unsigned short int. [Tru64 UNIX] The official
abbreviated company name of the operating system manufacturer.
If no value was specified for this variable, the
VENDOR_NAME value is returned. [Tru64 UNIX] The official
company name of the operating system manufacturer. Number
of bits in a word or type int.
System Standards Configuration Variables [Toc] [Back]
System standards configuration variables contain the minimum
values required by a particular system standard. The
prefixes of the variables indicate that the variables contain
the minimum values for system characteristics
required by particular standards. The correspondence
between the prefixes and standards is as follows:
----------------------------------------------------------------------------
Prefix Standard
----------------------------------------------------------------------------
_POSIX_ POSIX 1003.1 (POSIX.1)
POSIX2_ POSIX 1003.2 (POSIX.2)
_XOPEN_ X/Open
XBS5_ or _XBS5_ X/Open Version 5.1
_AES_ Open Software Foundation's AES system
standard
----------------------------------------------------------------------------
System standards are system-wide minimums that the system
meets to support the particular system standard. Actual
configuration values may exceed these standards. The system
standards configuration variables for the getconf command
are defined as follows: [Tru64 UNIX] The integer
value indicating the revision of the Application Environment
Specification to which the implementation is compliant.
The length of the arguments for one of the exec
functions, in bytes, including environment data. The maximum
number of simultaneous processes for each real user
ID. This variable has a value of 1 if the system supports
job control; otherwise, the variable is undefined. This
variable has a value other than -1 if the implementation
supports the creation of locales by the localedef utility.
The maximum value of a file's link count. The maximum
number of bytes in a terminal canonical input queue. The
maximum number of bytes for which space will be available
in a terminal input queue. The maximum number of bytes in
a file name. The maximum number of simultaneous supplementary
group IDs for each process. The maximum number of
files that one process can have open at one time. The
maximum number of bytes in a path name. The maximum number
of bytes that can be written atomically when writing
to a pipe. [Tru64 UNIX] This variable has a value of 1
if the system supports POSIX reentrant functions; otherwise,
the variable is undefined. This variable has a
value of 1 if each process has a saved set-user-ID and a
saved set-group-ID; otherwise, the variable is undefined.
The maximum value that can be stored in an object of type
ssize_t. The number of streams that one process can have
open at one time. [Tru64 UNIX] This variable has a value
of 1 if the system supports the POSIX threads stack size
attribute; otherwise, the variable is undefined. This
variable has a value other than -1 if the implementation
supports the priority inheritance option. This variable
has a value other than -1 if the implementation supports
the thread execution scheduling option. [Tru64
UNIX] This variable has a value of 1 if the system supports
POSIX threads; otherwise, the variable is undefined.
The maximum number of bytes supported for the name of a
time zone (not the length of the TZ environmental variable).
The date of approval of the most current version
of the POSIX.1 standard that the system supports. The date
is a 6-digit number, with the first 4 digits signifying
the year and the last 2 digits the month. Different versions
of the POSIX.1 standard are periodically approved by
the IEEE Standards Board, and the date of approval is used
to distinguish between different versions. The maximum
value allowed for the obase variable with the bc command.
The maximum number of elements permitted in an array by
the bc command. The maximum value allowed for the scale
variable with the bc command. The maximum of length
string constants accepted by the bc command. One or more
terminal types capable of all operations described in
ISO/IEC 9945. This value need not be present on a system
not supporting the User Portability Utilities Option. The
maximum number of weights that can be assigned to an entry
of the LC_COLLATE locale variable in a locale-definition
file. The maximum number of expressions that can be
nested within parentheses by the expr command. The maximum
length, in bytes, of a command's input line (either
standard input or another file) when the utility is
described as processing text files. The length includes
room for the trailing newline character. This variable
has a value of 1 if the system supports the creation of
new locales with the localedef command; otherwise, the
variable is undefined. The maximum number of repeated
occurrences of a regular expression permitted when using
the interval-notation parameters, such as the m and n
parameters with the ed command. This variable has a value
of 1 if the system supports the User Portability Utilities
Option; otherwise, the variable has a value of 0 (zero).
The date of approval of the most current version of the
POSIX.2 standard that the system supports. The date is a
6-digit number, with the first 4 digits signifying the
year and the last 2 digits the month. Different versions
of the POSIX.2 standard are periodically approved by the
IEEE Standards Board, and the date of approval is used to
distinguish between different versions. This variable has
a value of 1 if the system supports the optional C Language
Development Facilities specified by POSIX.2 and the
optional C Language Bindings Option from POSIX.2; otherwise,
the variable is undefined. This variable has a
value of 1 if the system supports the optional C Language
Development Utilities from POSIX.2; otherwise, the variable
is undefined. This value indicates the version of
the interfaces described in the C-Language Bindings Option
section of the XPG4 standard. This value changes with each
published version of ISO/IEC 9945 to indicate the 4-digit
year and 2-digit month that the standard was approved by
the IEEE Standards Board. This variable has a value of 1
if the system supports the FORTRAN Development Utilities
Option from POSIX.2; otherwise, the variable is undefined.
This variable has a value of 1 if the system supports the
FORTRAN Run-time Utilities Option from POSIX.2; otherwise,
the variable is undefined. This variable has a value of 1
if the system supports the Software Development Utilities
Option from POSIX.2; otherwise, the variable is undefined.
Same meanings as the -v specification variables. Note that
the corresponding specification variables do not have a
leading underscore. See "Specification Variables" for definitions.
These variables specify values to be passed to
utilities used in building an application. The name of the
parameter establishes type-size constraints for the environment
in which an application is being built: . The
int, long, pointer, and off_t types are treated as 32-bit
types. The int, long, and pointer types are treated as
32-bit types, and the off_t type is treated as a type with
at least 64 bits. The int type is treated as a 32-bit
type, and the long, pointer, and off_t types are treated
as 64-bit types The int type is treated as a type with at
least 32 bits, and the long, pointer, and off_t types are
treated as types with at least 64 bits.
The parameter suffix (id) identifies the component
affected by the type-size constraint: The value of
the parameter is the set of initial options (compilation
options) to be given to cc or c89. The
value of the parameter is the set of final options
(loader options) to be given to cc or c89. The
value of the parameter is the set of libraries to
be given to cc or c89. The value of the parameter
is the set of checking options to be given to lint.
In all cases, if sysconf (_SC_XBS5_ILP32_OFFBIG)
returns -1, the meaning of the passed values is
unspecified. This variable has a value other than
-1 if the implementation supports the X/Open
Encryption Feature Group. This variable has a
value other than -1 if the implementation supports
the X/Open Enhanced Internationalization Feature
Group. This variable has a value other than -1 if
the implementation supports the Legacy Feature
Group. This variable has a value other than -1 if
the implementation supports the X/Open Realtime
Feature Group. This variable has a value other
than -1 if the implementation supports the X/Open
Realtime Threads Feature Group. This variable has
a value other than -1 if the implementation supports
the X/Open Shared Memory Feature Group. An
integer indicating the most current version of the
X/OPEN standard that the system supports. An integer
value indicating the version of the XCU specification
to which the implementation conforms. If
the value is -1, no commands and utilities are provided
on the implementation. This variable is
defined only if the implementation supports the
X/Open Portability Guide, Volume 2, January 1987,
XVS System Calls and Libraries. This variable is
defined only if the implementation supports the
X/Open Specification, February 1992, System Interfaces
and Headers, Issue 3. This variable is
defined only if the implementation supports the
X/Open CAE Specification, July 1992, Systems Interfaces
and Headers, Issue 4.
System Path Configuration Variables [Toc] [Back]
The maximum value of a file's link count. If the pathname
argument refers to a directory, the value returned applies
to the directory itself. The maximum number of bytes in a
terminal canonical input queue. If the pathname argument
does not specify a terminal file, the getconf command
exits with a nonzero value. The maximum number of bytes
for which space will be available in a terminal input
queue. If the pathname argument does not specify a terminal
file, the getconf command exits with a nonzero value.
The maximum number of bytes in a file name. If the pathname
argument specifies a directory, the value returned
applies to the file names within the directory. The maximum
number of bytes in a path name. If the pathname argument
specifies a directory, the value returned is the maximum
length of a relative path name when the specified
directory is the working directory. The maximum number of
bytes that can be written atomically when writing to a
pipe. If the pathname argument specifies a FIFO or a pipe,
the value returned applies to that object. If the pathname
argument specifies a directory, the value returned applies
to any FIFO created in that directory. If the pathname
argument does not specify a directory or a FIFO file, the
getconf command exits with a nonzero value. This variable
has a value of 1 when the use of the chown function is
restricted to a process with appropriate privileges and
the group ID of a file can only be changed to the effective
group ID of the process or to one of its supplementary
group IDs. If the variable is undefined, it varies in
the system, depending upon the path. This variable has a
value of 1 when path names longer than the limit specified
by the NAME_MAX variable will generate an error. If the
variable is undefined, it varies in the system, depending
upon the path. When this variable has a value of 1, terminal
special characters, which are defined in the
<termios.h> header file, can be disabled. If the pathname
argument does not specify a terminal file, the getconf
command will exit with a nonzero value.
The following exit values are returned: The specified
variable is valid and information about its current state
has been displayed successfully. An error occurred.
To display the value of the ARG_MAX environment variable,
enter: getconf ARG_MAX To display the value of the
PATH_MAX environmental variable for the /usr directory,
enter: getconf PATH_MAX /usr
This sequence returns the following message: The
value of PATH_MAX in /usr is 1023
ENVIRONMENT VARIABLES [Toc] [Back] The following environment variables affect the execution
of getconf: Provides a default value for the internationalization
variables that are unset or null. If LANG is
unset or null, the corresponding value from the default
locale is used. If any of the internationalization variables
contain an invalid setting, the utility behaves as
if none of the variables had been defined. If set to a
non-empty string value, overrides the values of all the
other internationalization variables. Determines the
locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as
opposed to multibyte characters in arguments). Determines
the locale for the format and contents of diagnostic messages
written to standard error. Determines the location
of message catalogues for the processing of LC_MESSAGES.
Defines system configuration variables. Defines system
configuration variables. Defines terminal characteristics.
Commands: env(1)
Functions: pathconf(2)
Routines: confstr(3), sysconf(3)
Environment: environ(5)
Standards: standards(5)
getconf(1)
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