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From: rstevens@noao.edu (Rich Stevens)
Newsgroups: comp.unix.programmer
Subject: Re: ls & file pipes (FIFO), curses...
Summary: you have to mask st_mode to test file type
Message-ID: <1991Feb20.224434.24579@noao.edu>
Date: 20 Feb 91 22:44:34 GMT
References: <avalon.666979740@coombs> <471@bria>
Organization: National Optical Astronomy Observatories, Tucson AZ
Lines: 19

In article <471@bria> uunet!bria!mike writes:
>
>A file that is a named pipe shoould have S_IFIFO set in st_mode;
>such as:
>
>	if ( stat(file,&buf) != -1 && buf.st_mode & S_IFIFO )
                                      ^^^^^^^^^^^^^^^^^^^^^

You can't do this.  You *must* mask the st_mode member with S_IFMT
and then test for equality with the various file types.  Better yet,
use the POSIX-style S_ISxxx() macros.  The piece above should be

		((buf.st_mode & S_IFMT) == S_IFIFO)

For example, on SunOS "st_mode & S_IFREG" will be true for a regular file,
a sybolic link, and a socket.  Take a look at <sys.stat.h>.  Only 4 bits
are used to code 7 different values.

	Rich Stevens