pathconf, fpathconf - get configurable pathname variables
Standard C Library (libc, -lc)
pathconf(const char *path, int name);
fpathconf(int fd, int name);
The pathconf() and fpathconf() functions provides a method for applications
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 name argument
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 terminal canonical input line.
The minimum 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 the chown(2)
system call, otherwise 0.
Return 1 if file names longer than KERN_NAME_MAX are truncated.
Returns the terminal character disabling value.
Returns 1 of synchronized I/O is supported, otherwise 0.
If the maximum size file that could ever exist on the mounted
file system is maxsize, then the returned value is 2 plus the
floor of the base 2 logarithm of maxsize.
If the call to pathconf or fpathconf is not successful, -1 is returned
and errno is set appropriately. Otherwise, if the variable is associated
with functionality that does not have a limit in the system, -1 is
returned and errno is not modified. Otherwise, the current variable
value is returned.
If any of the following conditions occur, the pathconf and fpathconf
functions shall return -1 and set errno to the corresponding value.
[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 translating
[EIO] An I/O error occurred while reading from or writing to
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 conform to ISO/IEC 9945-1:1990
The pathconf and fpathconf functions first appeared in 4.4BSD.
BSD March 21, 1999 BSD
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