fpathconf(2) fpathconf(2)
NAME
fpathconf, pathconf - get configurable pathname variables
SYNOPSIS
#include <unistd.h>
long fpathconf (int fildes, int name);
long pathconf (char *path, int name);
DESCRIPTION
The functions fpathconf and pathconf return the current value of a
configurable limit or option associated with a file or directory.
The path argument points to the pathname of a file or directory;
fildes is an open file descriptor; and name is the symbolic constant
(defined in <unistd.h>) representing the configurable system limit or
option to be returned.
The values returned by pathconf and fpathconf depend on the type of
file specified by path or fildes. The following table contains the
symbolic constants supported by pathconf and fpathconf along with the
POSIX defined return value. The return value is based on the type of
file specified by path or fildes.
___________________________________
| Value of name | See Note|
|______________________|___________|
|______________________|___________|
| PCLINKMAX | 1 |
|______________________|___________|
| PCMAXCANNON | 2 |
|______________________|___________|
| PCMAXINPUT | 2 |
|______________________|___________|
| PCNAMEMAX | 3,4 |
|______________________|___________|
| PCPATHMAX | 4,5 |
|______________________|___________|
| PCPIPEBUF | 6 |
|______________________|___________|
| PCCHOWNRESTRICTED | 7 |
|______________________|___________|
| PCNOTRUNC | 3,4 |
|______________________|___________|
| PCVDISABLE | 2 |
|______________________|___________|
Notes:
1 If path or fildes refers to a directory, the value returned
applies to the directory itself.
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fpathconf(2) fpathconf(2)
2 The behavior is undefined if path or fildes does not refer to a
terminal file.
3 If path or fildes refers to a directory, the value returned
applies to the filenames within the directory.
4 The behavior is undefined if path or fildes does not refer to a
directory.
5 If path or fildes refers to a directory, the value returned is
the maximum length of a relative pathname when the specified
directory is the working directory.
6 If path or fildes refers to a pipe or FIFO, the value returned
applies to the FIFO itself. If path or fildes refers to a
directory, the value returned applies to any FIFOs that exist
or can be created within the directory. If path or fildes
refer to any other type of file, the behavior is undefined.
7 If path or fildes refers to a directory, the value returned
applies to any files, other than directories, that exist or can
be created within the directory.
The value of the configurable system limit or option specified by
name does not change during the lifetime of the calling process.
fpathconf fails if the following is true:
EBADF fildes is not a valid file descriptor.
pathconf fails if one or more of the following are true:
EACCES search permission is denied for a component of the path prefix.
ELOOP too many symbolic links are encountered while translating path.
EMULTIHOP
components of path require hopping to multiple remote machines
and file system type does not allow it.
ENAMETOOLONG
the length of a pathname exceeds {PATHMAX}, or pathname
component is longer than {NAMEMAX} while (POSIXNOTRUNC) is
in effect.
ENOENT path is needed for the command specified and the named file
does not exist or if the path argument points to an empty
string.
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fpathconf(2) fpathconf(2)
ENOLINK
path points to a remote machine and the link to that machine
is no longer active.
ENOTDIR
a component of the path prefix is not a directory.
Both fpathconf and pathconf fail if the following is true:
EINVAL if name is an invalid value.
SEE ALSO
sysconf(3C), limits(4).
DIAGNOSTICS
If fpathconf or pathconf are invoked with an invalid symbolic
constant or the symbolic constant corresponds to a configurable
system limit or option not supported on the system, a value of -1 is
returned to the invoking process. If the function fails because the
configurable system limit or option corresponding to name is not
supported on the system the value of errno is not changed.
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