NAME
creat - create a new file
SYNOPSIS
(creat = 8.)
sys creat; name; mode
(file descriptor in r0)
creat(name, mode)
char *name;
DESCRIPTION
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.
See chmod (II) 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 (in r0).
The mode given is arbitrary; it need not allow writing.
This feature is used by programs which deal with temporary
files of fixed names. The creation is done with a mode that
forbids writing. Then if a second instance of the program
attempts a creat, an error is returned and the program knows
that the name is unusable for the moment.
SEE ALSO
write (II), close (II), stat (II)
DIAGNOSTICS
The error bit (c-bit) may be set if: a needed directory is
not searchable; the file does not exist and the directory in
which it is to be created is not writable; the file does
exist and is unwritable; the file is a directory; there are
already too many files open.
From C, a -1 return indicates an error.
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