Add some more *at() system calls.
[dragonfly.git] / lib / libc / sys / mkfifo.2
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28.\" @(#)mkfifo.2 8.1 (Berkeley) 6/4/93
6d98f93c 29.\" $FreeBSD: src/lib/libc/sys/mkfifo.2,v 1.23 2008/04/16 13:03:12 kib Exp $
984263bc 30.\"
6d98f93c 31.Dd August 6, 2010
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32.Dt MKFIFO 2
33.Os
34.Sh NAME
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35.Nm mkfifo ,
36.Nm mkfifoat
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37.Nd make a fifo file
38.Sh LIBRARY
39.Lb libc
40.Sh SYNOPSIS
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41.In sys/stat.h
42.Ft int
43.Fn mkfifo "const char *path" "mode_t mode"
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44.Ft int
45.Fn mkfifoat "int fd" "const char *path" "mode_t mode"
984263bc 46.Sh DESCRIPTION
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47The
48.Fn mkfifo
49system call
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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.
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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 .
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83.Sh RETURN VALUES
84.Rv -std mkfifo
85.Sh ERRORS
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86The
87.Fn mkfifo
88system call
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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
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101A component of the path prefix denies search permission, or write permission
102is denied on the parent directory of the fifo to be created.
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103.It Bq Er ELOOP
104Too many symbolic links were encountered in translating the pathname.
105.It Bq Er EROFS
6d98f93c 106The named file would reside on a read-only file system.
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107.It Bq Er EEXIST
108The named file exists.
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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.
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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
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137The
138.Fa path
139argument
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140points outside the process's allocated address space.
141.El
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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
984263bc 166.Sh SEE ALSO
6d98f93c 167.Xr chflags 2 ,
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168.Xr chmod 2 ,
169.Xr mknod 2 ,
170.Xr stat 2 ,
171.Xr umask 2
172.Sh STANDARDS
173The
174.Fn mkfifo
6d98f93c 175system call is expected to conform to
984263bc 176.St -p1003.1-90 .
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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 .