11/3/71 SYS CREAT (II)
NAME creat -- create a new file
SYNOPSIS sys creat; name; mode / creat = 8.
(file descriptor in r0)
DESCRIPTION creat creates a new file or prepares to rewrite
an existing file called name; name is the address
of a null-terminated string. If the file did not
exist, it is given mode mode; if it 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 writ-
ing. 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.
If the last link to an open file is removed, the
file is not destroyed until the file is closed.
FILES --
SEE ALSO write, close
DIAGNOSTICS The error bit (c-bit) may be set if: a needed di-
rectory is not readable; the file does not exist
and the directory in which it is to be created is
not writable; the file does exist and is un-
writable; the file is a directory;
BUGS --
OWNER ken, dmr