GETCONF(1) | General Commands Manual | GETCONF(1) |
getconf
— retrieve
standard configuration variables
getconf |
-a [file] |
getconf |
[-v environment]
path_var file |
getconf |
[-v environment]
system_var |
The getconf
utility prints the values of
POSIX or X/Open path or system configuration variables to the standard
output. If a variable is undefined, the string
“undefined
” is output.
The first form of the command displays all of the path or system configuration variables to standard output. If file is provided, all path configuration variables are reported for file using pathconf(2). Otherwise, all system configuration variables are reported using confstr(3) and sysconf(3).
The second form of the command, with two mandatory arguments,
retrieves file- and file system-specific configuration variables using
pathconf(2). The third form, with a
single argument, retrieves system configuration variables using
confstr(3) and
sysconf(3), depending on the type of
variable. As an extension, the second form can also be used to query static
limits from <limits.h>
.
All sysconf(3) and
pathconf(2) variables use the same
name as the manifest constants defined in the relevant standard C-language
bindings, including any leading underscore or prefix. That is to say,
system_var might be ARG_MAX
or
_POSIX_VERSION
, as opposed to the
sysconf(3) names
_SC_ARG_MAX
or
_SC_POSIX_VERSION
. Variables retrieved from
confstr(3) have the leading
‘_CS_
’ stripped off; thus,
_CS_PATH
is queried by a
system_var of
“PATH
”.
The -v
environment
option specifies a IEEE Std 1003.1-2001
(“POSIX.1”) programming environment under which the
values are to be queried. This option currently does nothing, but may in the
future be used to select between 32-bit and 64-bit execution environments on
platforms which support both. Specifying an environment which is not
supported on the current execution platform gives undefined results.
The standard programming environments are as follows:
POSIX_V6_ILP32_OFF32
POSIX_V6_ILP32_OFFBIG
POSIX_V6_LP64_OFF64
POSIX_V6_LPBIG_OFFBIG
The command:
getconf
POSIX_V6_WIDTH_RESTRICTED_ENVS
returns a newline-separated list of environments in which the width of certain fundamental types is no greater than the width of the native C type long. At present, all programming environments supported by FreeBSD have this property. Several of the confstr(3) variables provide information on the necessary compiler and linker flags to use the standard programming environments described above.
Many of these values are also available through the sysctl(8) mechanism.
The getconf
utility exits 0 on
success, and >0 if an error occurs.
The command:
getconf PATH
will display the system default setting for the
PATH
environment variable.
The command:
getconf NAME_MAX /tmp
will display the maximum length of a filename in the /tmp directory.
The command:
getconf -v POSIX_V6_LPBIG_OFFBIG
LONG_MAX
will display the maximum value of the C type
long in the
POSIX_V6_LPBIG_OFFBIG
programming environment, if
the system supports that environment.
Use of a system_var or
path_var which is completely unrecognized is
considered an error, causing a diagnostic message to be written to standard
error. One which is known but merely undefined does not result in an error
indication. The getconf
utility recognizes all of
the variables defined for IEEE Std 1003.1-2001
(“POSIX.1”), including those which are not currently
implemented.
The getconf
utility is expected to be
compliant with IEEE Std 1003.1-2001
(“POSIX.1”).
The getconf
utility first appeared in
FreeBSD 5.0.
Garrett A. Wollman <wollman@lcs.mit.edu>
September 15, 2017 | macOS 14.6 |