pathconf
When your machine allows different files to have different values for a file system parameter, you can use the functions in this section to find out the value that applies to any particular file.
These functions and the associated constants for the parameter argument are declared in the header file `unistd.h'.
The parameter argument should be one of the `_PC_' constants listed below.
The normal return value from pathconf
is the value you requested.
A value of -1
is returned both if the implementation does not
impose a limit, and in case of an error. In the former case,
errno
is not set, while in the latter case, errno
is set
to indicate the cause of the problem. So the only way to use this
function robustly is to store 0
into errno
just before
calling it.
Besides the usual file name errors (see section File Name Errors), the following error condition is defined for this function:
EINVAL
pathconf
except that an open file descriptor
is used to specify the file for which information is requested, instead
of a file name.
The following errno
error conditions are defined for this function:
EBADF
EINVAL
Here are the symbolic constants that you can use as the parameter
argument to pathconf
and fpathconf
. The values are all
integer constants.
_PC_LINK_MAX
LINK_MAX
.
_PC_MAX_CANON
MAX_CANON
.
_PC_MAX_INPUT
MAX_INPUT
.
_PC_NAME_MAX
NAME_MAX
.
_PC_PATH_MAX
PATH_MAX
.
_PC_PIPE_BUF
PIPE_BUF
.
_PC_CHOWN_RESTRICTED
_POSIX_CHOWN_RESTRICTED
.
_PC_NO_TRUNC
_POSIX_NO_TRUNC
.
_PC_VDISABLE
_POSIX_VDISABLE
.
_PC_SYNC_IO
_POSIX_SYNC_IO
.
_PC_ASYNC_IO
_POSIX_ASYNC_IO
.
_PC_PRIO_IO
_POSIX_PRIO_IO
.
_PC_SOCK_MAXBUF
_POSIX_PIPE_BUF
.
_PC_FILESIZEBITS
_PC_REC_INCR_XFER_SIZE
POSIX_REC_INCR_XFER_SIZE
.
_PC_REC_MAX_XFER_SIZE
POSIX_REC_MAX_XFER_SIZE
.
_PC_REC_MIN_XFER_SIZE
POSIX_REC_MIN_XFER_SIZE
.
_PC_REC_XFER_ALIGN
POSIX_REC_XFER_ALIGN
.
Go to the first, previous, next, last section, table of contents.