getconf -- retrieve standard configuration variables
getconf [-v environment] path_var file
getconf [-v environment] system_var
The getconf utility prints the value of a POSIX or X/Open path or system
configuration variable to the standard output. If the specified variable
is undefined, the string ``undefined'' is output.
The first form of the command, with two mandatory arguments, retrieves
file- and file system-specific configuration variables using pathconf(2).
The second 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''.
Programming Environments [Toc] [Back]
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 Exactly 32-bit integer, long, pointer, and
file offset. Supported platforms: None.
POSIX_V6_ILP32_OFFBIG Exactly 32-bit integer, long, and pointer;
at least 64-bit file offset. Supported
platforms: IA32, PowerPC.
POSIX_V6_LP64_OFF64 Exactly 32-bit integer; exactly 64-bit long,
pointer, and file offset. Supported
platforms: Alpha, SPARC64.
POSIX_V6_LPBIG_OFFBIG At least 32-bit integer; at least 64-bit
long, pointer, and file offset. Supported
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.
The getconf utility exits 0 on success, and >0 if an error occurs. 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.
will display the system default setting for the PATH environment variable.
getconf NAME_MAX /tmp
will display the maximum length of a filename in the /tmp directory.
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
pathconf(2), confstr(3), sysconf(3)
The getconf utility is expected to be compliant with IEEE Std 1003.1-2001
The getconf utility first appeared in FreeBSD 5.0.
Garrett A. Wollman <email@example.com>
FreeBSD 5.2.1 September 18, 2002 FreeBSD 5.2.1 [ Back ]