FPATHCONF(3)

NAME
fpathconf, pathconf - get configuration values for files

SYNOPSIS
#include <unistd.h>

long fpathconf(int filedes, int name);
long pathconf(char *path, int name);

DESCRIPTION
fpathconf() gets a value for the configuration option name for the open file descriptor filedes.

pathconf() gets a value for configuration option name for the file name path.

The corresponding macros defined in <unistd.h> are minimum values; if an application wants to take advantage of values which may change, a call to fpathconf() or pathconf() can be made, which may yield more liberal results.

Setting name equal to one of the following constants returns the following configuration options:

_PC_LINK_MAX
    returns the maximum number of links to the file. If filedes or path refer to a directory, then the value applies to the whole directory. The corresponding macro is _POSIX_LINK_MAX.

_PC_MAX_CANON
    returns the maximum length of a formatted input line, where filedes or path must refer to a terminal. The corresponding macro is _POSIX_MAX_CANON.

_PC_MAX_INPUT
    returns the maximum length of an input line, where filedes or path must refer to a terminal. The corresponding macro is _POSIX_MAX_INPUT.

_PC_NAME_MAX
    returns the maximum length of a filename in the directory path or filedes. the process is allowed to create. The corresponding macro is _POSIX_NAME_MAX.

_PC_PATH_MAX
    returns the maximum length of a relative pathname when path or filedes is the current working directory. The corresponding macro is _POSIX_PATH_MAX.

_PC_PIPE_BUF
    returns the size of the pipe buffer, where filedes must refer to a pipe or FIFO and path must refer to a FIFO. The corresponding macro is _POSIX_PIPE_BUF.

_PC_CHOWN_RESTRICTED
    returns nonzero if the chown(2) call may not be used on this file. If filedes or path refer to a directory, then this applies to all files in that directory. The corresponding macro is _POSIX_CHOWN_RESTRICTED.

_PC_NO_TRUNC
    returns nonzero if accessing filenames longer than _POSIX_NAME_MAX generates an error. The corresponding macro is _POSIX_NO_TRUNC.

_PC_VDISABLE
    returns nonzero if special character processing can be disabled, where filedes or path must refer to a terminal.

RETURN VALUE
The limit is returned, if one exists. If the system does not have a limit for the requested resource, -1 is returned, and errno is unchanged. If there is an error, -1 is returned, and errno is set to reflect the nature of the error.

CONFORMING TO
POSIX.1

NOTES
Files with name lengths longer than the value returned for name equal to _PC_NAME_MAX may exist in the given directory.

Some returned values may be huge; they are not suitable for allocating memory.

SEE ALSO
getconf(1), statfs(2), open(2), sysconf(3)