diff options
Diffstat (limited to 'lib/libc/sys/open.2')
| -rw-r--r-- | lib/libc/sys/open.2 | 64 |
1 files changed, 58 insertions, 6 deletions
diff --git a/lib/libc/sys/open.2 b/lib/libc/sys/open.2 index 7e9ea5dfb50..45b4ee28d8f 100644 --- a/lib/libc/sys/open.2 +++ b/lib/libc/sys/open.2 @@ -1,4 +1,4 @@ -.\" $OpenBSD: open.2,v 1.38 2011/07/12 18:41:38 matthew Exp $ +.\" $OpenBSD: open.2,v 1.39 2011/07/18 23:04:40 matthew Exp $ .\" $NetBSD: open.2,v 1.8 1995/02/27 12:35:14 cgd Exp $ .\" .\" Copyright (c) 1980, 1991, 1993 @@ -30,16 +30,19 @@ .\" .\" @(#)open.2 8.2 (Berkeley) 11/16/93 .\" -.Dd $Mdocdate: July 12 2011 $ +.Dd $Mdocdate: July 18 2011 $ .Dt OPEN 2 .Os .Sh NAME -.Nm open +.Nm open , +.Nm openat .Nd open or create a file for reading or writing .Sh SYNOPSIS .Fd #include <fcntl.h> .Ft int .Fn open "const char *path" "int flags" "mode_t mode" +.Ft int +.Fn openat "int fd" "const char *path" "int flags" "mode_t mode" .Sh DESCRIPTION The file name specified by .Fa path @@ -62,7 +65,8 @@ and modified by the process' umask value (see .Pp The flags specified are formed by bitwise-inclusive .Tn OR Ns 'ing -the following values. +the following values defined in +.In fcntl.h . Exactly one of the first three values (file access modes) must be specified: .Pp .Bl -tag -width O_DIRECTORY -offset indent -compact @@ -185,6 +189,30 @@ The system imposes a limit on the number of file descriptors open simultaneously by one process. .Xr getdtablesize 3 returns the current system limit. +.Pp +The +.Fn openat +function is equivalent to +.Fn open +except that where +.Fa path +specifies a relative path, +the file to be opened is determined relative to +the directory associated with file descriptor +.Fa fd +instead of the current working directory. +.Pp +If +.Fn openat +is passed the special value +.Dv AT_FDCWD +(defined in +.In fcntl.h ) +in the +.Fa fd +parameter, the current working directory is used +and the behavior is identical to a call to +.Fn open . .Sh RETURN VALUES If successful, .Fn open @@ -193,7 +221,11 @@ Otherwise, a value of \-1 is returned and .Va errno is set to indicate the error. .Sh ERRORS -The named file is opened unless: +The +.Fn open +and +.Fn openat +functions will fail if: .Bl -tag -width Er .It Bq Er ENOTDIR A component of the path prefix is not a directory. @@ -324,6 +356,20 @@ An attempt was made to open a socket (not currently implemented). An attempt was made to open a terminal device that requires exclusive access and the specified device has already be opened. .El +.Pp +Additionally, the +.Fn openat +function will fail if: +.Bl -tag -width Er +.It Bq Er EBADF +The +.Fa path +argument does not specify an absolute path and the +.Fa fd +argument is neither +.Dv AT_FDCWD +nor a valid file descriptor open for reading. +.El .Sh SEE ALSO .Xr chflags 2 , .Xr chmod 2 , @@ -338,7 +384,9 @@ access and the specified device has already be opened. .Sh STANDARDS The .Fn open -function conforms to +and +.Fn openat +functions conform to .St -p1003.1-2008 . .Pp .Dv POSIX @@ -362,6 +410,10 @@ An .Fn open function call appeared in .At v2 . +The +.Fn openat +function call appeared in +.Ox 5.0 . .Sh CAVEATS The .Dv O_TRUNC |