pathconf, fpathconf - get configurable pathname variables
pathconf(const char *path, int name);
fpathconf(int fd, int name);
The pathconf() and fpathconf() functions provides a method
to determine the current value of a configurable system limit or
option variable associated with a pathname or file descriptor.
For pathconf, the path argument is the name of a file or directory. For
fpathconf, the fd argument is an open file descriptor. The
specifies the system variable to be queried. Symbolic constants for each
name value are found in the include file <unistd.h>.
The available values are as follows:
The maximum file link count.
The maximum number of bytes in a terminal canonical
The maximum number of bytes for which space is
available in a
terminal input queue.
The maximum number of bytes in a file name.
The maximum number of bytes in a pathname.
The maximum number of bytes which will be written
atomically to a
Return 1 if appropriate privileges are required for
system call, otherwise 0.
Return 1 if file names longer than KERN_NAME_MAX are
Returns the terminal character disabling value.
If the call to pathconf or fpathconf is not successful, -1
and errno is set appropriately. Otherwise, if the variable
with functionality that does not have a limit in the system,
-1 is returned
and errno is not modified. Otherwise, the current
If any of the following conditions occur, the pathconf and
functions shall return -1 and set errno to the corresponding
[EINVAL] The value of the name argument is invalid.
[EINVAL] The implementation does not support an association of the
variable name with the associated file.
pathconf() will fail if:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an
entire path name exceeded 1023 characters.
[ENOENT] The named file does not exist.
[EACCES] Search permission is denied for a component
of the path
[ELOOP] Too many symbolic links were encountered in
[EIO] An I/O error occurred while reading from or
the file system.
fpathconf() will fail if:
[EBADF] fd is not a valid open file descriptor.
[EIO] An I/O error occurred while reading from or writing to the file
The pathconf and fpathconf functions first appeared in
OpenBSD 3.6 June 4, 1993
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