Re: [9fans] rc - how to...

Re: [9fans] rc - how to...

[Fco.J.Ballesteros]

If the input contains '; rm -rf *', I go and kill the user (not the
process). In a finite number of steps you get good input files.

Re: [9fans] rc - how to...

[Jim Choate]

On Fri, 13 Sep 2002, Fco.J.Ballesteros wrote:

> If the input contains '; rm -rf *', I go and kill the user (not the
> process). In a finite number of steps you get good input files.

Or they kill you, which seems more likely. Users outnumber operators
by a considerable factor.


 --
    ____________________________________________________________________

    We don't see things as they are,                      ravage@ssz.com
    we see them as we are.                                   www.ssz.com
                                                  jchoate@open-forge.org
    Anais Nin                                         www.open-forge.org

    --------------------------------------------------------------------

Re: [9fans] rc - how to...

[rog]

> Most of the times I wanted to do "while read { x }" I could
> rewrite it to be "sed 's/^/x /' | rc", which works like a charm.

...until your input contains ";rm -rf *"...

Re: [9fans] rc - how to...

[Fco.J.Ballesteros]

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Most of the times I wanted to do "while read { x }" I could
rewrite it to be "sed 's/^/x /' | rc", which works like a charm.

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From: rog@vitanuova.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] rc - how to...
Date: Thu, 12 Sep 2002 15:42:38 +0100
Message-ID: <35d1a51a345858e759eea904502ce78e@vitanuova.com>

> du / | while(file=`{read})
> 	echo $file

it's probably worth mentioning that this is really quite slow, as the
read command is unable to do any IO buffering, must read one
character at a time, and is reloaded on every line of input:

on my machine,
	while (file=`{read}) {}

exececutes about 85 lines a second, whereas a simple xargs-like
program processes about 4300.

this could be quite significant if you're using to process
output from du (what was viable in the old bourne
shell with

	du . | while read x
	do something with $x
	done

is not necessarily fast enough in the rc equivalent)

Re: [9fans] rc - how to...

[rog]

> du / | while(file=`{read})
> 	echo $file

it's probably worth mentioning that this is really quite slow, as the
read command is unable to do any IO buffering, must read one
character at a time, and is reloaded on every line of input:

on my machine,
	while (file=`{read}) {}

exececutes about 85 lines a second, whereas a simple xargs-like
program processes about 4300.

this could be quite significant if you're using to process
output from du (what was viable in the old bourne
shell with

	du . | while read x
	do something with $x
	done

is not necessarily fast enough in the rc equivalent)

Re: [9fans] rc - how to...

[Russ Cox]

du / | while(file=`{read})
	echo $file

Russ

[9fans] rc - how to...

[steve.simon]

Hi,

I like rc's language very much, but, I cannot work out how to
read a series of words from a slow running program, for example:

for ( file in `{du /} )
    echo $file(1)

This runs the du and then processes the output of it.
I want to read du's output a line at a time so I get dataflow
and see the output of each line as they are processed.

I would use the read(1) command in Bourne shell but
cannot see an equivalent in rc.

Anyone help?

Thanks,

-Steve