term% cat index.txt CREAT(2) System Calls Manual CREAT(2)
NAME
creat - create a new file
SYNOPSIS
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, 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 re‐
turned.
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 sec‐
ond 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(2), close(2), chmod(2), umask (2)
DIAGNOSTICS
The value -1 is returned 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 di‐
rectory; there are already too many files open.
ASSEMBLER
(creat = 8.)
sys creat; name; mode
(file descriptor in r0)
CREAT(2)