Article on oreilly.net on how to build Unix tools with Ruby

[Xavier]

Thought you'd like to know about this article
This links to the printable version, much easier to read.
[url]http://linux.oreillynet.com/lpt/a/4159[/url]

Enjoy.

[Paul Brannan]

On Sat, Sep 20, 2003 at 06:00:21AM +0900, Xavier wrote:

> Thought you'd like to know about this article
> This links to the printable version, much easier to read.
> [url]http://linux.oreillynet.com/lpt/a/4159[/url]
>
> Enjoy.

A pretty good article, though:
1. It would be nice if it mentioned optparse, which is a little
cleaner than getoptlong for what the author is doing.
2. Using "while line = gets do" is just as clean as "while gets", but
doesn't require the use of $_. I suspect the author came from a
perl background.
3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
instead of #!/usr/local/bin/ruby.

Paul

[Geoffrey S. Knauth]

Xavier <NOSPAM@keepyourspam.com> wrote:

> Thought you'd like to know about this article
> This links to the printable version, much easier to read.
> [url]http://linux.oreillynet.com/lpt/a/4159[/url]

Nice script for handling CSVs. But it doesn't handle commas embedded in
double quotes (yet).

--
Geoffrey S. Knauth | [url]http://knauth.org/gsk[/url]

[Jim Menard]

[email]geoff@knauth.org[/email] (Geoffrey S. Knauth) writes:

> Xavier <NOSPAM@keepyourspam.com> wrote:

> > Thought you'd like to know about this article
> > This links to the printable version, much easier to read.
> > [url]http://linux.oreillynet.com/lpt/a/4159[/url]

>
> Nice script for handling CSVs. But it doesn't handle commas embedded in
> double quotes (yet).

If anyone wants one, I've got a DelimParser class that handles different
delimiters and quote marks as well as delimiters, escaped characters, and
doubled quotes that appear in the data.

It doesn't use regexps. It's a simple state machine that walks through each
character in the input.

Ask and thou shall receive.

Jim
--
Jim Menard, [email]jimm@io.com[/email], [url]http://www.io.com/~jimm/[/url]
"$665.95: The Retail Price of the Beast" -- Unknown

[Michael Campbell]

> If anyone wants one, I've got a DelimParser class that handles
different

> delimiters and quote marks as well as delimiters, escaped

characters, and

> doubled quotes that appear in the data.
>
> It doesn't use regexps. It's a simple state machine that walks
> through each character in the input.
>
> Ask and thou shall receive.

I'd like to get a copy of that please.

I've used [url]http://raa.ruby-lang.org/list.rhtml?name=csv[/url] in the past,
and while it works for my feeble CSV needs, I find the interface
somewhat [overly] complex.


__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software
[url]http://sitebuilder.yahoo.com[/url]

[gabriele renzi]

il 23 Sep 2003 15:06:01 -0500, Jim Menard <jimm@io.com> ha scritto::

>It doesn't use regexps. It's a simple state machine that walks through each
>character in the input.
>
>Ask and thou shall receive.

would you please send me a copy or publish it on RAA ?

[Jim Menard]

gabriele renzi <surrender_it@remove.yahoo.it> writes:

> il 23 Sep 2003 15:06:01 -0500, Jim Menard <jimm@io.com> ha scritto::
>

> >It doesn't use regexps. It's a simple state machine that walks through each
> >character in the input.
> >
> >Ask and thou shall receive.

>
>
> would you please send me a copy or publish it on RAA ?
>

Gabriele,

I emailed it to you and Michael and posted it to
<http://www.io.com/~jimm/downloads/index.html>.

Jim
--
Jim Menard, [email]jimm@io.com[/email], [url]http://www.io.com/~jimm/[/url]
"Unix is extremely user-friendly. It also happens to be extremely
selective when picking its friends." -- Daniel E. Macks

[Jim Freeze]

On Wednesday, 24 September 2003 at 5:15:41 +0900, Jim Menard wrote:

> [email]geoff@knauth.org[/email] (Geoffrey S. Knauth) writes:
>

> > Xavier <NOSPAM@keepyourspam.com> wrote:

> > > Thought you'd like to know about this article
> > > This links to the printable version, much easier to read.
> > > [url]http://linux.oreillynet.com/lpt/a/4159[/url]

> >
> > Nice script for handling CSVs. But it doesn't handle commas embedded in
> > double quotes (yet).

>

I have found that the csv parser by NaHi to be very good and
full featured.

[url]http://raa.ruby-lang.org/list.rhtml?name=csv[/url]


--
Jim Freeze
----------
God made the world in six days, and was arrested on the seventh.

[Gavin Sinclair]

On Wednesday, September 24, 2003, 2:33:01 AM, Paul wrote:

> 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
> instead of #!/usr/local/bin/ruby.

Can someone please explain to me what /usr/bin/env/ruby does?

Thanks,
Gavin

[Michael W Thelen]

* Gavin Sinclair <gsinclair@soyabean.com.au> [2003-09-23 17:16]:

> On Wednesday, September 24, 2003, 2:33:01 AM, Paul wrote:

> > 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
> > instead of #!/usr/local/bin/ruby.

>
> Can someone please explain to me what /usr/bin/env/ruby does?

Note that there's no slash between "env" and "ruby"... env is a program that
lets you run a program in a modified environment, and it's also useful on the
shebang line if you don't know the exact location of the interpreter you want
to run. It will find the executable in the path before executing it.

-- Mike

--
Michael W. Thelen
Experience is what you get when you don't get what you want.
-- Dan Stanford

[Jim Freeze]

On Wednesday, 24 September 2003 at 8:24:36 +0900, Michael W Thelen wrote:

> * Gavin Sinclair <gsinclair@soyabean.com.au> [2003-09-23 17:16]:

> > On Wednesday, September 24, 2003, 2:33:01 AM, Paul wrote:

> > > 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
> > > instead of #!/usr/local/bin/ruby.

> >
> > Can someone please explain to me what /usr/bin/env/ruby does?

Speaking of env, does this work on linux when options are passed
to ruby?

I'm not at a linux terminal right now, but when the shebang is:

/usr/bin/env ruby -w

I get the error that ruby -w is not found.
The gnu manual says that it should work, but it certainly
doesn't work as it does on FreeBSD or Sun.

The distro is RH 7.3.


--
Jim Freeze
----------
Adore, v.:
To venerate expectantly.
-- Ambrose Bierce, "The Devil's Dictionary"

[Paul Brannan]

On Wed, Sep 24, 2003 at 09:04:55AM +0900, Jim Freeze wrote:

> Speaking of env, does this work on linux when options are passed
> to ruby?

No, it doesn't. I've seen a detailed explanation somewhere on a perl
mailing list or newsgroup, but I can't remember the specifics.

Paul

[NAKAMURA, Hiroshi]

Hi,

> From: "Jim Freeze" <jim@freeze.org>
> Sent: Wednesday, September 24, 2003 7:05 AM

> > > Xavier <NOSPAM@keepyourspam.com> wrote:
> > > > Thought you'd like to know about this article
> > > > This links to the printable version, much easier to read.
> > > > [url]http://linux.oreillynet.com/lpt/a/4159[/url]
> > >
> > > Nice script for handling CSVs. But it doesn't handle commas embedded in
> > > double quotes (yet).

> I have found that the csv parser by NaHi to be very good and
> full featured.
>
> [url]http://raa.ruby-lang.org/list.rhtml?name=csv[/url]

And is bundled in ruby from 1.8...
It can parse <<__EOS__.chomp
a,b,",","""","\r\n","\r","\n"
__EOS__

Of cource it must have easy interface!
Any suggestion are welcome. How do you want to write
parsing code?

Regards,
// NaHi

PS. Current interface;

SYNOPSIS

1. reader = CSV.open( filename, "r" )

2. CSV.open( filename, "r" ) do | row |
...
end

3. writer = CSV.open( filename, "w" )

4. CSV.open( filename, "w" ) do | writer |
...
end

ARGS

filename: filename to open.
mode: "r" for read (parse)
"w" for write (generate)
row: an Array of cells which is a parsed line.
writer: Created writer instance. See CSV::Writer#<< and
CSV::Writer#addRow to know how to generate CSV string.

RETURNS

reader: Create reader instance. To get parse result, see
CSV::Reader#each.
writer: Created writer instance. See CSV::Writer#<< and
CSV::Writer#addRow to know how to generate CSV string.

DESCRIPTION

Open a CSV formatted file to read or write.

EXAMPLE 1

reader = CSV.open( "csvfile.csv", "r" )
row1 = reader.shift
row2 = reader.shift
if row2.empty?
p "row2 not find."
end
reader.close

EXAMPLE 2

CSV.open( "csvfile.csv", "r" ) do | row |
p row
end

EXAMPLE 3

writer = CSV.open( "csvfile.csv", "w" )
writer << [ "r1c1", "r1c2" ] << [ "r2c1", "r2c2" ] << [ nil, nil ]
writer.close

EXAMPLE 4

CSV.open( "csvfile.csv", "w" ) do | writer |
writer << [ "r1c1", "r1c2" ]
writer << [ "r2c1", "r2c2" ]
writer << [ nil, nil ]
end

[NAKAMURA, Hiroshi]

Hi,

> From: "NAKAMURA, Hiroshi" <nakahiro@sarion.co.jp>
> Sent: Wednesday, September 24, 2003 11:54 AM

> Of cource it must have easy interface!
> Any suggestion are welcome. How do you want to write
> parsing code?

I didn't mean "it must be easy already without any modification".
I mean "it should have easy interface if the current interface
is not easy".

Where's my teacher of English composition?

Regards,
// NaHi

[Bermejo, Rodrigo]

Paul Brannan wrote:

>
>
> 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
> instead of #!/usr/local/bin/ruby.
>
>Paul
>
>
>

advantages ?

-r.

[Jim Freeze]

On Wednesday, 24 September 2003 at 12:30:24 +0900, Bermejo, Rodrigo wrote:

>
> Paul Brannan wrote:
>

> >
> >
> > 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
> > instead of #!/usr/local/bin/ruby.
> >

> advantages ?
>

I thought someone had already mentioned the advantages.
Basically, you don't need to know the path of ruby.
So, if you are distributing an application, your app
will run no matter where ruby is installed.

There are also options that you can pass to env to
control environment variables.

The main disadvantage is that using env increases
the security risk over a hard coded path.

--
Jim Freeze
----------
It is now 10 p.m. Do you know where Henry Kissinger is?
-- Elizabeth Carpenter

[David Garamond]

> On Sat, Sep 20, 2003 at 06:00:21AM +0900, Xavier wrote:

>

>>Thought you'd like to know about this article
>>This links to the printable version, much easier to read.
>>[url]http://linux.oreillynet.com/lpt/a/4159[/url]
>>
>>Enjoy.

Speaking of Unix tools, do any of the Perlians in this list remember Tom
Christiansen's pet project Perl Power Tools?

[url]http://www.perl.com/language/ppt/[/url]

The project aims to rewrite many Unix commands in Perl, from simple
commands like 'echo', 'clear', and 'cat' to moderately complex ones like
'cp', 'find', and 'ls' to complex ones like 'awk', 'make', and 'm4'.
Take a look at the URL above, they seem to have implemented a good chunk
of them.

Perhaps someone with extra free time on his hands would like to take a
stab on a Ruby Power Tools project? ;-)

--
dave

[Mike Stok]

In article <20030923200517.A36392@freeze.org>,
Jim Freeze <jim@freeze.org> wrote:

>On Wednesday, 24 September 2003 at 8:24:36 +0900, Michael W Thelen wrote:

>> * Gavin Sinclair <gsinclair@soyabean.com.au> [2003-09-23 17:16]:

>> > On Wednesday, September 24, 2003, 2:33:01 AM, Paul wrote:
>> > > 3. I wish he'd mentioned the option of using #!/usr/bin/env ruby
>> > > instead of #!/usr/local/bin/ruby.
>> >
>> > Can someone please explain to me what /usr/bin/env/ruby does?

>
>Speaking of env, does this work on linux when options are passed
>to ruby?
>
>I'm not at a linux terminal right now, but when the shebang is:
>
> /usr/bin/env ruby -w
>
> I get the error that ruby -w is not found.
> The gnu manual says that it should work, but it certainly
> doesn't work as it does on FreeBSD or Sun.

One way of getting arounf env's ignoring ARGS iff you are just doing -w
is to put

$VERBOSE = true

after the shebang line. See
[url]http://mail.gnu.org/archive/html/bug-sh-utils/2002-04/msg00020.html[/url]
for an explanation.

Hope this helps,

Mike

--
[email]mike@stok.co.uk[/email] | The "`Stok' disclaimers" apply.
[url]http://www.stok.co.uk/~mike/[/url] | GPG PGP Key 1024D/059913DA
[email]mike@exegenix.com[/email] | Fingerprint 0570 71CD 6790 7C28 3D60
[url]http://www.exegenix.com/[/url] | 75D2 9EC4 C1C0 0599 13DA

[Jim Freeze]

On Wednesday, 24 September 2003 at 20:18:42 +0900, Mike Stok wrote:

> In article <20030923200517.A36392@freeze.org>,

> >
> > I get the error that ruby -w is not found.
> > The gnu manual says that it should work, but it certainly
> > doesn't work as it does on FreeBSD or Sun.

>
> One way of getting arounf env's ignoring ARGS iff you are just doing -w
> is to put
>
> $VERBOSE = true
>
> after the shebang line. See

Yes, that is our current work around. It's probably the better
convention because it is reliable for all platforms.


--
Jim Freeze
----------
All things are possible, except skiing thru a revolving door.

[Tom Copeland]

On Wed, 2003-09-24 at 02:23, David Garamond wrote:

> Speaking of Unix tools, do any of the Perlians in this list remember Tom
> Christiansen's pet project Perl Power Tools?
>
> [url]http://www.perl.com/language/ppt/[/url]
>
> The project aims to rewrite many Unix commands in Perl, from simple
> commands like 'echo', 'clear', and 'cat' to moderately complex ones like
> 'cp', 'find', and 'ls' to complex ones like 'awk', 'make', and 'm4'.
> Take a look at the URL above, they seem to have implemented a good chunk
> of them.
>
> Perhaps someone with extra free time on his hands would like to take a
> stab on a Ruby Power Tools project? ;-)

rpt.rubyforge.org is still available...

Yours,

Tom
--
Tom Copeland <tom@infoether.com>
InfoEther