FPATHCONF(3) Linux Programmer s Manual FPATHCONF(3)

NAME fpathconf, pathconf - get configuration values for files

SYNOPSIS #include <unistd.h>

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

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

pathconf() gets a value for configuration option name for the filename 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 fol- lowing configuration options:

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

_PC_MAX_CANON returns the maximum length of a formatted input line, where fd 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 fd 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 fd that 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 fd is the current working directory. The corresponding macro is _POSIX_PATH_MAX.

_PC_PIPE_BUF returns the size of the pipe buffer, where fd 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 non-zero if the chown(2) call may not be used on this file. If fd 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 non-zero if accessing filenames longer than _POSIX_NAME_MAX generates an error. The corresponding macro is _POSIX_NO_TRUNC.

_PC_VDISABLE returns non-zero if special character processing can be dis- abled, where fd 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.1-2001.

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), open(2), statfs(2), sysconf(3)

COLOPHON This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.

GNU 1993-04-04 FPATHCONF(3)