[comp.unix.questions] Named Pipes

twh@mibte.UUCP (Tim Hitchcock) (11/09/87)

Need reference on "named pipes."


Thanks in Advance,

Tim Hitchcock

latham@ablnc.ATT.COM (Ken Latham) (11/10/87)

In article <2370@mibte.UUCP>, twh@mibte.UUCP (Tim Hitchcock) writes:
> Need reference on "named pipes."
> 
> Tim Hitchcock

A "Named pipe" is a FIFO file (UNIX SYS V), a particular variety
of file which you can create using  mknod(2) or  mknod(1M).

As would be suspected from the name this is nothing more than a file
in which the first character written is the first character read, but
what is special is that the read is destructive.  Once the character is
read it cannot be read again.  Effectively this is a "file pipe" or
"named pipe".

It is the only SPECIAL file a NON-super-user may create.

You use the mknod(2) call, setting the appropriate bit in the mode. (0010000)
Other than this the open is no different than any other type of regular
file open.

See the "Programmer's Reference Manual" for mknod(2).
See the "Administrator's Reference Manual" for mknod(1M).


					Ken Latham
					UNIX Technical Support
					ihnp4!ablnc!latham