mkfifo(3c) - osol9

1mkfifo(3C)               Standard C Library Functions               mkfifo(3C)
2
3
4

NAME

6       mkfifo - make a FIFO special file
7

SYNOPSIS

9       #include <sys/types.h>
10       #include <sys/stat.h>
11
12       int mkfifo(const char *path, mode_t mode);
13
14

DESCRIPTION

16       The  mkfifo()  function  creates  a  new FIFO special file named by the
17       pathname pointed to by path.  The file permission bits of the new  FIFO
18       are  initialized from mode.  The file permission bits of the mode argu‐
19       ment are modified by the process's file creation mask  (see  umask(2)).
20       Bits other than the file permission bits in mode are ignored.
21
22
23       If path names a symbolic link, mkfifo() fails and sets errno to EEXIST.
24
25
26       The  FIFO's  user  ID  is  set  to the process's effective user ID. The
27       FIFO's group ID is set to the group ID of the parent  directory  or  to
28       the effective group ID of the process.
29
30
31       The mkfifo() function calls mknod(2) to create the file.
32
33
34       Upon  successful  completion,  mkfifo()  marks for update the st_atime,
35       st_ctime, and st_mtime fields of  the  file.  Also,  the  st_ctime  and
36       st_mtime fields of the directory that contains the new entry are marked
37       for update.
38

RETURN VALUES

40       Upon successful completion, 0 is returned.  Otherwise, −1  is  returned
41       and errno is set to indicate the error.
42

ERRORS

44       The mkfifo() function will fail if:
45
46       EACCES          A  component  of  the path prefix denies search permis‐
47                       sion, or write  permission  is  denied  on  the  parent
48                       directory of the FIFO to be created.
49
50
51       EEXIST          The named file already exists.
52
53
54       ELOOP           A loop exists in symbolic links encountered during res‐
55                       olution of the path argument.
56
57
58       ENAMETOOLONG    The length of the path argument exceeds {PATH_MAX} or a
59                       pathname component is longer than {NAME_MAX}.
60
61
62       ENOENT          A  component  of the path prefix specified by path does
63                       not name an existing directory  or  path  is  an  empty
64                       string.
65
66
67       ENOSPC          The directory that would contain the new file cannot be
68                       extended or the file system is out  of  file-allocation
69                       resources.
70
71
72       ENOTDIR         A component of the path prefix is not a directory.
73
74
75       EROFS           The named file resides on a read-only file system.
76
77
78
79       The mkfifo() function may fail if:
80
81       ELOOP           Too  many  symbolic links were encountered in resolving
82                       path.
83
84
85       ENAMETOOLONG    The length of the path argument exceeds {PATH_MAX} or a
86                       pathname component is longer than {NAME_MAX}.
87
88

EXAMPLES

90       Example 1 Create a FIFO File
91
92
93       The  following  example  demonstrates  how  to create a FIFO file named
94       /home/cnd/mod_done with read and write permissions for  the  owner  and
95       read permissions for the group and others.
96
97
98         #include sys/types.h>
99         #include sys/stat.h>
100         int status;
101         ...
102         status = mkfifo("/home/cnd/mod_done", S_IWUSR | S_IRUSR |
103                 S_IRGRP | S_IROTH);
104
105

ATTRIBUTES

107       See attributes(5) for descriptions of the following attributes:
108
109
110
111
112       ┌─────────────────────────────┬─────────────────────────────┐
113       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
114       ├─────────────────────────────┼─────────────────────────────┤
115       │Interface Stability          │Standard                     │
116       ├─────────────────────────────┼─────────────────────────────┤
117       │MT-Level                     │MT-Safe                      │
118       └─────────────────────────────┴─────────────────────────────┘
119