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NAME

       mkfifo - make a FIFO special file (a named pipe)

SYNOPSIS

       #include <sys/types.h>
       #include <sys/stat.h>

       int mkfifo(const char *pathname, mode_t mode);

DESCRIPTION

       mkfifo()  makes a FIFO special file with name pathname.  mode specifies
       the FIFO’s permissions.  It is modified by the process’s umask  in  the
       usual way: the permissions of the created file are (mode & ~umask).

       A  FIFO special file is similar to a pipe, except that it is created in
       a different way.  Instead of being an anonymous communications channel,
       a  FIFO  special  file  is  entered  into  the  file  system by calling
       mkfifo().

       Once you have created a FIFO special file in this way, any process  can
       open  it  for  reading or writing, in the same way as an ordinary file.
       However, it has to be open at both ends simultaneously before  you  can
       proceed to do any input or output operations on it.  Opening a FIFO for
       reading normally blocks until some other process opens  the  same  FIFO
       for  writing,  and vice versa.  See fifo(7) for nonblocking handling of
       FIFO special files.

RETURN VALUE

       On success mkfifo() returns 0.  In the case of an error, -1 is returned
       (in which case, errno is set appropriately).

ERRORS

       EACCES One  of  the  directories  in  pathname  did  not  allow  search
              (execute) permission.

       EEXIST pathname already exists.  This includes the case where  pathname
              is a symbolic link, dangling or not.

       ENAMETOOLONG
              Either the total length of pathname is greater than PATH_MAX, or
              an individual filename  component  has  a  length  greater  than
              NAME_MAX.   In  the  GNU  system,  there  is no imposed limit on
              overall filename length, but some file systems may place  limits
              on the length of a component.

       ENOENT A  directory  component  in  pathname  does  not  exist  or is a
              dangling symbolic link.

       ENOSPC The directory or file system has no room for the new file.

       ENOTDIR
              A component used as a directory in pathname is not, in  fact,  a
              directory.

       EROFS  pathname refers to a read-only file system.

CONFORMING TO

       POSIX.1-2001.

SEE ALSO

       mkfifo(1),  close(2),  open(2),  read(2),  stat(2), umask(2), write(2),
       mkfifoat(3), fifo(7)

COLOPHON

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