CREAT(2)

NAME
creat - create a new file

SYNOPSIS
#include <sys/types.h>
#include <fcntl.h>
int creat(const char *name, mode_t mode)

DESCRIPTION
This interface is made obsolete by open(2), it is equivalent to

    open(name, O_WRONLY | O_CREAT | O_TRUNC, mode)

Creat creates a new file or prepares to rewrite an existing file called name, given as the address of a null-terminated string. If the file did not exist, it is given mode mode, as modified by the process's mode mask (see umask(2)). Also see chmod(2) for the construction of the mode 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 mode given is arbitrary; it need not allow writing. This feature has been used in the past by programs to construct a simple, exclusive locking mechanism. It is replaced by the O_EXCL open mode, or the advisory locking of the fcntl(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
Creat will fail and the file will not be created or truncated if one of the following occur:

[ENOTDIR]
    A component of the path prefix is not a directory.

[ENAMETOOLONG]
    The path name exceeds PATH_MAX characters.

[ENOENT]
    The named file does not exist.

[ELOOP]
    Too many symbolic links were encountered in translating the pathname. (Minix-vmd)

[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.

[EROFS]
    The named file resides on a read-only file system.

[ENXIO]
    The file is a character special or block special file, and the associated device does not exist.

[EIO]
    An I/O error occurred while making the directory entry or allocating the inode.

[EFAULT]
    Name points outside the process's allocated address space.

SEE ALSO
open(2), write(2), close(2), chmod(2), umask(2).