fpathconf, pathconf - get configuration values for files
Synopsis
Description
Notes
#include <unistd.h>long fpathconf(int filedes, int name); long pathconf(char *path, int name);
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.
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.
POSIX.1
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.
getconf(1), statfs(2), open(2), sysconf(3)
| GNU | FPATHCONF (3) | 1993-04-04 |