1.\" $OpenBSD: mkfifo.2,v 1.8 2007/05/31 19:19:33 jmc Exp $ 2.\" $NetBSD: mkfifo.2,v 1.8 1995/02/27 12:34:27 cgd Exp $ 3.\" 4.\" Copyright (c) 1990, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)mkfifo.2 8.1 (Berkeley) 6/4/93 32.\" 33.Dd $Mdocdate: May 31 2007 $ 34.Dt MKFIFO 2 35.Os 36.Sh NAME 37.Nm mkfifo 38.Nd make a FIFO file 39.Sh SYNOPSIS 40.Fd #include <sys/types.h> 41.Fd #include <sys/stat.h> 42.Ft int 43.Fn mkfifo "const char *path" "mode_t mode" 44.Sh DESCRIPTION 45.Fn mkfifo 46creates a new FIFO file with name 47.Fa path . 48The access permissions are 49specified by 50.Fa mode 51and restricted by the 52.Xr umask 2 53of the calling process. 54.Pp 55The FIFO's owner ID is set to the process's effective user ID. 56The FIFO's group ID is set to that of the parent directory in 57which it is created. 58.Sh RETURN VALUES 59A 0 return value indicates success. 60A \-1 return value indicates an error, and an error code is stored in 61.Va errno . 62.Sh ERRORS 63.Fn mkfifo 64will fail and no FIFO will be created if: 65.Bl -tag -width Er 66.It Bq Er EOPNOTSUPP 67The kernel has not been configured to support FIFOs. 68.It Bq Er ENOTDIR 69A component of the path prefix is not a directory. 70.It Bq Er ENAMETOOLONG 71A component of a pathname exceeded 72.Dv {NAME_MAX} 73characters, or an entire path name exceeded 74.Dv {PATH_MAX} 75characters. 76.It Bq Er ENOENT 77A component of the path prefix does not exist. 78.It Bq Er EACCES 79Search permission is denied for a component of the path prefix. 80.It Bq Er ELOOP 81Too many symbolic links were encountered in translating the pathname. 82.It Bq Er EROFS 83The named file resides on a read-only file system. 84.It Bq Er EEXIST 85The named file exists. 86.It Bq Er ENOSPC 87The directory in which the entry for the new FIFO is being placed 88cannot be extended because there is no space left on the file 89system containing the directory. 90.It Bq Er ENOSPC 91There are no free inodes on the file system on which the 92FIFO is being created. 93.It Bq Er EDQUOT 94The directory in which the entry for the new FIFO 95is being placed cannot be extended because the 96user's quota of disk blocks on the file system 97containing the directory has been exhausted. 98.It Bq Er EDQUOT 99The user's quota of inodes on the file system on 100which the FIFO is being created has been exhausted. 101.It Bq Er EIO 102An 103.Tn I/O 104error occurred while making the directory entry or allocating the inode. 105.It Bq Er EIO 106An 107.Tn I/O 108error occurred while reading from or writing to the file system. 109.It Bq Er EFAULT 110.Fa path 111points outside the process's allocated address space. 112.El 113.Sh SEE ALSO 114.Xr chmod 2 , 115.Xr stat 2 , 116.Xr umask 2 117.Sh STANDARDS 118The 119.Nm mkfifo 120function call conforms to 121.St -p1003.1-88 . 122