[unix-history] / usr / man / man2 / creat.2

.TH CREAT 2 
.SH NAME
creat \- create a new file
.SH SYNOPSIS
.B creat(name, mode)
.br
.B char *name;
.SH DESCRIPTION
.I Creat
creates a new file or prepares to rewrite an existing
file called 
.I name,
given as the address of a null-terminated string.
If the file did not exist, it is given
mode
.IR mode ,
as modified by the process's mode mask (see
.IR umask (2)).
Also see
.IR  chmod (2)
for the
construction of the
.I mode
argument.
.PP
If the file did exist, its mode and owner remain unchanged
but it is truncated to 0 length.
.PP
The file is also opened for writing, and its file descriptor
is returned.
.PP
The
.I 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
.I creat,
an error is
returned and the program knows that the name is unusable
for the moment.
.SH "SEE ALSO"
write(2), close(2), chmod(2), umask (2)
.SH 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 directory;
there are already too many files open.
.SH "ASSEMBLER (PDP-11)"
(creat = 8.)
.br
.B sys creat; name; mode
.br
(file descriptor in r0)
.SH BUGS
A file cannot be truncated while any process
has pages set up by a
.I vread
on that file which have not been referenced.
Commit	Line	Data
5ffa3a26 BJ	1	.TH CREAT 2
	2	.SH NAME
	3	creat \- create a new file
	4	.SH SYNOPSIS
	5	.B creat(name, mode)
	6	.br
	7	.B char *name;
	8	.SH DESCRIPTION
	9	.I Creat
	10	creates a new file or prepares to rewrite an existing
	11	file called
	12	.I name,
	13	given as the address of a null-terminated string.
	14	If the file did not exist, it is given
	15	mode
	16	.IR mode ,
	17	as modified by the process's mode mask (see
	18	.IR umask (2)).
	19	Also see
	20	.IR chmod (2)
	21	for the
	22	construction of the
	23	.I mode
	24	argument.
	25	.PP
	26	If the file did exist, its mode and owner remain unchanged
	27	but it is truncated to 0 length.
	28	.PP
	29	The file is also opened for writing, and its file descriptor
	30	is returned.
	31	.PP
	32	The
	33	.I mode
	34	given is arbitrary; it need not allow
	35	writing.
	36	This feature is used by programs which deal with temporary
	37	files of fixed names.
	38	The creation is done with
	39	a mode that forbids writing.
	40	Then if a second
	41	instance of the program attempts a
	42	.I creat,
	43	an error is
	44	returned and the program knows that the name is unusable
	45	for the moment.
	46	.SH "SEE ALSO"
	47	write(2), close(2), chmod(2), umask (2)
	48	.SH DIAGNOSTICS
	49	The value \-1 is returned if:
	50	a needed directory is not searchable;
	51	the file does not exist and the directory
	52	in which it is to be created is not writable; the file
	53	does exist and is unwritable;
	54	the file is a directory;
	55	there are already too many files open.
	56	.SH "ASSEMBLER (PDP-11)"
	57	(creat = 8.)
	58	.br
	59	.B sys creat; name; mode
	60	.br
	61	(file descriptor in r0)
	62	.SH BUGS
	63	A file cannot be truncated while any process
	64	has pages set up by a
65	.I vread
66	on that file which have not been referenced.