From mboxrd@z Thu Jan  1 00:00:00 1970
Subject: Re: [9fans] page as a presentation tool
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From: Rob Pike <rob@mightycheese.com>
To: 9fans@cse.psu.edu
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Message-Id: <36000D8C-0FD9-11D8-A204-000A95B984D8@mightycheese.com>
Date: Wed,  5 Nov 2003 13:44:19 -0800
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> Thanks.  That solves the problem with 'u'.  The problem with 'x',
> I fear, is my own misunderstanding of sam's syntax.  sam doesn't
> allow a space between 'x' and its regular expression argument, though
> it is quite happy to allow one between 'c' and its regular expression
> argument.  Since this first bit me on the UNIX version I assumed it
> was a problem with the UNIX version.

'c' doesn't have a regular expression argument.  but anyway, i know
what you're talking about.

there's a notational shorthand that may be the source of your confusion.

x/foo/ command

looks for foo and runs the command.  one useful value of foo is lines:

x/.*\n?/ command

this is so common that it's given a shorthand: an absent pattern:

x command

thus one may write

x g/bar/  command

to run the command on every line containing bar.  but,

x /foo/ command

means for every line, run

	/foo/ command

which isn't what you want at all.  obviously, this is a huge semantic
swing for the measly addition of a space. mea culpa.

-rob