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Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)mkfifo.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/sys/mkfifo.2,v 1.23 2008/04/16 13:03:12 kib Exp $ 30.\" 31.Dd August 6, 2010 32.Dt MKFIFO 2 33.Os 34.Sh NAME 35.Nm mkfifo , 36.Nm mkfifoat 37.Nd make a fifo file 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/stat.h 42.Ft int 43.Fn mkfifo "const char *path" "mode_t mode" 44.Ft int 45.Fn mkfifoat "int fd" "const char *path" "mode_t mode" 46.Sh DESCRIPTION 47The 48.Fn mkfifo 49system call 50creates a new fifo file with name 51.Fa path . 52The access permissions are 53specified by 54.Fa mode 55and restricted by the 56.Xr umask 2 57of the calling process. 58.Pp 59The fifo's owner ID is set to the process's effective user ID. 60The fifo's group ID is set to that of the parent directory in 61which it is created. 62.Pp 63The 64.Fn mkfifoat 65system call is equivalent to 66.Fn mkfifo 67except in the case where 68.Fa path 69specifies a relative path. 70In this case the newly created FIFO is created relative to the 71directory associated with the file descriptor 72.Fa fd 73instead of the current working directory. 74If 75.Fn mkfifoat 76is passed the special value 77.Dv AT_FDCWD 78in the 79.Fa fd 80parameter, the current working directory is used and the behavior is 81identical to a call to 82.Fn mkfifo . 83.Sh RETURN VALUES 84.Rv -std mkfifo 85.Sh ERRORS 86The 87.Fn mkfifo 88system call 89will fail and no fifo will be created if: 90.Bl -tag -width Er 91.It Bq Er ENOTSUP 92The kernel has not been configured to support fifo's. 93.It Bq Er ENOTDIR 94A component of the path prefix is not a directory. 95.It Bq Er ENAMETOOLONG 96A component of a pathname exceeded 255 characters, 97or an entire path name exceeded 1023 characters. 98.It Bq Er ENOENT 99A component of the path prefix does not exist. 100.It Bq Er EACCES 101A component of the path prefix denies search permission, or write permission 102is denied on the parent directory of the fifo to be created. 103.It Bq Er ELOOP 104Too many symbolic links were encountered in translating the pathname. 105.It Bq Er EROFS 106The named file would reside on a read-only file system. 107.It Bq Er EEXIST 108The named file exists. 109.It Bq Er EPERM 110The parent directory of the named file has its immutable flag set, see the 111.Xr chflags 2 112manual page for more information. 113.It Bq Er ENOSPC 114The directory in which the entry for the new fifo is being placed 115cannot be extended because there is no space left on the file 116system containing the directory. 117.It Bq Er ENOSPC 118There are no free inodes on the file system on which the 119fifo is being created. 120.It Bq Er EDQUOT 121The directory in which the entry for the new fifo 122is being placed cannot be extended because the 123user's quota of disk blocks on the file system 124containing the directory has been exhausted. 125.It Bq Er EDQUOT 126The user's quota of inodes on the file system on 127which the fifo is being created has been exhausted. 128.It Bq Er EIO 129An 130.Tn I/O 131error occurred while making the directory entry or allocating the inode. 132.It Bq Er EIO 133An 134.Tn I/O 135error occurred while reading from or writing to the file system. 136.It Bq Er EFAULT 137The 138.Fa path 139argument 140points outside the process's allocated address space. 141.El 142.Pp 143In addition to the errors returned by the 144.Fn mkfifo , 145the 146.Fn mkfifoat 147may fail if: 148.Bl -tag -width Er 149.It Bq Er EBADF 150The 151.Fa path 152argument does not specify an absolute path and the 153.Fa fd 154argument is neither 155.Dv AT_FDCWD 156nor a valid file descriptor open for searching. 157.It Bq Er ENOTDIR 158The 159.Fa path 160argument is not an absolute path and 161.Fa fd 162is neither 163.Dv AT_FDCWD 164nor a file descriptor associated with a directory. 165.El 166.Sh SEE ALSO 167.Xr chflags 2 , 168.Xr chmod 2 , 169.Xr mknod 2 , 170.Xr stat 2 , 171.Xr umask 2 172.Sh STANDARDS 173The 174.Fn mkfifo 175system call is expected to conform to 176.St -p1003.1-90 . 177The 178.Fn mkfifoat 179system call follows The Open Group Extended API Set 2 specification. 180.Sh HISTORY 181The 182.Fn mkfifoat 183system call appeared in 184.Dx 2.7 . 185