Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!ames!mailrus!tut.cis.ohio-state.edu!mandrill!gatech!udel!rochester!cornell!batcomputer!sun.soe.clarkson.edu!nelson
From: nelson@sun.soe.clarkson.edu (Russ Nelson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: using "/" in pathnames
Message-ID: <1009@sun.soe.clarkson.edu>
Date: 30 May 88 02:14:01 GMT
References: <1238@bingvaxu.cc.binghamton.edu>
Reply-To: nelson@sun.soe.clarkson.edu (Russ Nelson)
Organization: Clarkson University, Potsdam, NY
Lines: 40

In article <1238@bingvaxu.cc.binghamton.edu> sullivan@marge.math.binghamton.edu (fred sullivan) writes:
>Some time ago someone complained about having to use "\" in MSDOS
>pathnames.  I just submitted to comp.binaries.ibm.pc a program to
>fix this.  Similar programs are available as part of Dan Norton's
>package of tools (swchar) and from simtel20 
>(pd1:<msdos.keyboard>switchar.*).

Several caveats about '/' vs '\' in pathnames:

  o Theoretically, '/' is usable in pathnames at all times.
  o The Set Switchar (3701h) and Get Switchar (3700h) DOS functions *are*
    documented.  Don't let Microsoft tell you otherwise.  I will send a
    photocopy of the page in Zenith's Programmers Utility Package that
    documents the call to anyone who sends me an SASE.
  o Command.com thinks that '/' is the switchar.  Using the Set Switchar
    DOS call, you can set the switchar to '-'.  This lets you use '/' as
    a pathname separator.
  o Most PC Magazine programs and the Norton Utilities ignore the
    switchar='-' setting.  In certain places, they parse the pathname,
    looking ONLY for '\'.
  o DOS Backup is rumored to go whacko with switchar=-.
  o Turbo C has two undocumented functions in its library: setswitchar(char c),
    and char getswitchar().  They do just what you think they do.
  o All of the software I write is guaranteed to work with switchar=-.  :-)

If you are interested in writing software that works with switchar=-,
then do this:
  o if (getswitchar() == '/') Pathchar = '\\' else Pathchar = '/';
  o When parsing pathnames, search for '\' OR Pathchar.
  o Of course, when parsing parameters, look for your switches to begin
    with getswitchar().

Typically, when I find a useful PC Magazine utility, I modify it to use
switchar=-.  Thank goodness that they have the good sense to publish
source!

-- 
char *reply-to-russ(int network) {
if(network == BITNET) return "NELSON@CLUTX";
else return "nelson@clutx.clarkson.edu"; }