IPC using named pipe Post: 99194

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IPC using named pipe

Hi All, I am facing a vague issue while trying to make two process talk to each other using named pipe. read process ========= The process which reads, basically creates FIFO using mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666) func. It then opens the pipe using open func - fd = open...

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mkfifo

MKFIFO(3)						     Linux Programmer's Manual							 MKFIFO(3)

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 chan-
       nel, 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

       This page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2008-06-12								 MKFIFO(3)

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