4.3BSD-UWisc/man/cat2/creat.2
CREAT(2) UNIX Programmer's Manual CREAT(2)
NAME
creat - create a new file
SYNOPSIS
creat(name, mode)
char *name;
DESCRIPTION
This interface is made obsolete by open(2).
_C_r_e_a_t creates a new file or prepares to rewrite an existing
file called _n_a_m_e, given as the address of a null-terminated
string. If the file did not exist, it is given mode _m_o_d_e,
as modified by the process's mode mask (see _u_m_a_s_k(2)). Also
see _c_h_m_o_d(2) for the construction of the _m_o_d_e argument.
If the file did exist, its mode and owner remain unchanged
but it is truncated to 0 length.
The file is also opened for writing, and its file descriptor
is returned.
NOTES
The _m_o_d_e given is arbitrary; it need not allow writing.
This feature has been used in the past by programs to con-
struct a simple, exclusive locking mechanism. It is
replaced by the O_EXCL open mode, or _f_l_o_c_k(2) facility.
RETURN VALUE
The value -1 is returned if an error occurs. Otherwise, the
call returns a non-negative descriptor that only permits
writing.
ERRORS
_C_r_e_a_t will fail and the file will not be created or trun-
cated if one of the following occur:
[ENOTDIR] A component of the path prefix is not a
directory.
[EINVAL] The pathname contains a character with the
high-order bit set.
[ENAMETOOLONG] A component of a pathname exceeded 255 char-
acters, or an entire path name exceeded 1023
characters.
[ENOENT] The named file does not exist.
[ELOOP] Too many symbolic links were encountered in
translating the pathname.
Printed 12/27/86 May 22, 1986 1
CREAT(2) UNIX Programmer's Manual CREAT(2)
[EACCES] Search permission is denied for a component
of the path prefix.
[EACCES] The file does not exist and the directory in
which it is to be created is not writable.
[EACCES] The file exists, but it is unwritable.
[EISDIR] The file is a directory.
[EMFILE] There are already too many files open.
[ENFILE] The system file table is full.
[ENOSPC] The directory in which the entry for the new
file is being placed cannot be extended
because there is no space left on the file
system containing the directory.
[ENOSPC] There are no free inodes on the file system
on which the file is being created.
[EDQUOT] The directory in which the entry for the new
file is being placed cannot be extended
because the user's quota of disk blocks on
the file system containing the directory has
been exhausted.
[EDQUOT] The user's quota of inodes on the file system
on which the file is being created has been
exhausted.
[EROFS] The named file resides on a read-only file
system.
[ENXIO] The file is a character special or block spe-
cial file, and the associated device does not
exist.
[ETXTBSY] The file is a pure procedure (shared text)
file that is being executed.
[EIO] An I/O error occurred while making the direc-
tory entry or allocating the inode.
[EFAULT] _N_a_m_e points outside the process's allocated
address space.
[EOPNOTSUPP] The file was a socket (not currently imple-
mented).
Printed 12/27/86 May 22, 1986 2
CREAT(2) UNIX Programmer's Manual CREAT(2)
SEE ALSO
open(2), write(2), close(2), chmod(2), umask(2)
Printed 12/27/86 May 22, 1986 3