CREAT(2) CREAT(2)
NAME
creat - create a new file or rewrite an existing one
SYNOPSIS
int creat (path, mode)
char *path;
int mode;
DESCRIPTION
creat creates a new ordinary file or prepares to rewrite an
existing file named by the path name pointed to by path.
If the file exists, the length is truncated to 0 and the
mode and owner are unchanged. Otherwise, the file's owner
ID is set to the effective user ID, of the process the group
ID of the process is set to the effective group ID, of the
process and the low-order 12 bits of the file mode are set
to the value of mode modified as follows:
All bits set in the process's file mode creation mask
are cleared [see umask(2)].
The ``save text image after execution bit'' of the mode
is cleared [see chmod(2)].
Upon successful completion, a write-only file descriptor is
returned and the file is open for writing, even if the mode
does not permit writing. The file pointer is set to the
beginning of the file. The file descriptor is set to remain
open across exec system calls [see fcntl(2)]. No process
may have more than 20 files open simultaneously, see NOFILES
[defined in /usr/include/sys/param.h]. A new file may be
created with a mode that forbids writing.
creat fails if one or more of the following are true:
[ENOTDIR] A component of the path prefix is not a
directory.
[ENOENT] A component of the path prefix does not
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CREAT(2) CREAT(2)
exist.
[EACCES] Search permission is denied on a component of
the path prefix.
[ENOENT] The path name is null.
[EACCES] The file does not exist and the directory in
which the file is to be created does not
permit writing.
[EROFS] The named file resides or would reside on a
read-only file system.
[ETXTBSY] The file is a pure procedure (shared text)
file that is being executed.
[EACCES] The file exists and write permission is
denied.
[EISDIR] The named file is an existing directory.
[EMFILE] NOFILES file descriptors are currently open.
[EFAULT] Path points outside the allocated address
space of the process.
[ENFILE] The system file table is full.
[EAGAIN] The file exists, mandatory file/record
locking is set, and there are outstanding
record locks on the file [see chmod(2)].
[EINTR] A signal was caught during the creat system
call.
[ENOLINK] Path points to a remote machine and the link
to that machine is no longer active.
[EMULTIHOP] Components of path require hopping to
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CREAT(2) CREAT(2)
multiple remote machines.
[ENOSPC] The file system is out of inodes.
SEE ALSO
chmod(2), close(2), dup(2), fcntl(2), lseek(2), open(2),
read(2), umask(2), write(2).
DIAGNOSTICS
Upon successful completion, a non-negative integer, namely
the file descriptor, is returned. Otherwise, a value of -1
is returned and errno is set to indicate the error.
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