fpathconf(2) fpathconf(2) NAME fpathconf, pathconf - get configurable pathname variables SYNOPSIS #include <unistd.h> long fpathconf (int fildes, int name); long pathconf (const 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 <sys/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. The return value is based on the type of file specified by path or fildes. ___________________________________ Value of name See Note ___________________________________ ___________________________________ _PC_FILESIZEBITS 3,4 ___________________________________ _PC_LINK_MAX 1 ___________________________________ _PC_MAX_CANON 2 ___________________________________ _PC_MAX_INPUT 2 ___________________________________ _PC_NAME_MAX 3,4 ___________________________________ _PC_PATH_MAX 4,5 ___________________________________ _PC_PIPE_BUF 6 ___________________________________ _PC_CHOWN_RESTRICTED 7 ___________________________________ _PC_NO_TRUNC 3,4 ___________________________________ _PC_VDISABLE 2 ___________________________________ _PC_ASYNC_IO 8 ___________________________________ _PC_ABI_ASYNC_IO 8 ___________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ____________________________________ _PC_ABI_AIO_XFER_MAX 8 ___________________________________ _PC_SYNC_IO 8 ___________________________________ _PC_PRIO_IO 8 ___________________________________ | | | | | | | | | | | | | | | | | | | | | Notes: 1 If path or fildes refers to a directory, the value returned applies to the directory itself. 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. 8 The behavior is undefined if path or fildes refers to a 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: EACCES Read permission is denied on the named file. 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 {PATH_MAX}, or pathname component is longer than {NAME_MAX} while (_POSIX_NO_TRUNC) 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. ENOLINKpath points to a remote machine and the link to that machine is no longer active. ETIMEDOUT A component of path resides on a remote system which is not available [see intro(2)]. ENOTDIRa 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), ulimit(2), limits(4). DIAGNOSTICS If the configurable system limit or option corresponding to name is not supported on the system, -1 is returned and the value of errno is not changed. If the option corresponding to name is known but of unlimited value for the given path, -1 is returned and the value of errno is not changed. If fpathconf or pathconf are invoked with an invalid symbolic constant, -1 is returned and errno is set to indicate the error. Page 3