11/3/71 SYS CREAT (II)





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
squoze.net
