Asp Forum - Ruby wildcard command line argument auto expansion

Michael Jia

6/9/2007 9:40:00 AM

I want to pass in wildcard file names, and use it to match file names
located in different directories. For example, *.txt will match file
such as "my.txt", "you.txt", etc.

However, I found out ruby intepreter automatically expands "*.txt"
command argument to a array of filenames which matches that wildcard in
the current directory.

For example:

C:\working>dir *.txt

05/10/2007 03:24 PM 46,101 config.txt
11/23/2004 11:54 AM 361 tips.txt
2 File(s) 46,462 bytes

If you do,

C:\working>ruby -e "puts ARGV" *.txt
config.txt
tips.txt

Ruby converts string *.txt into the matching filenames and pass in the
expanded array as the new argument.

This *nice* trick sometime creates trouble.

In my case, I want to use 'ARGV[0]' to match filenames in a different
location. But ARGV[0] is not "*.txt" as my expected. It was changed by
ruby. In fact, it is "config.txt" in this case.

One way to correct it is to always ask user to use single-quoted string:

C:\working>ruby -e "puts ARGV" '*.txt'
*.txt

--
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13 Answers

Michael Jia

6/9/2007 9:41:00 AM

Is there a better way to disbale this auto expansion?

Thanks
Michael

> One way to correct it is to always ask user to use single-quoted string:
>
> C:\working>ruby -e "puts ARGV" '*.txt'
> *.txt

--
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Tim Hunter

6/9/2007 11:14:00 AM

Michael Jia wrote:
> Is there a better way to disbale this auto expansion?
>
> Thanks
> Michael
>
>
>> One way to correct it is to always ask user to use single-quoted string:
>>
>> C:\working>ruby -e "puts ARGV" '*.txt'
>> *.txt
>>
>
>
>
The filename expansion is a function of the command window, not Ruby. By
the time Ruby starts up the expansion has already happened. I think the
only way to disable it is to put quotes around the argument.

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Gregor Schmidt

6/9/2007 11:35:00 AM

Hallo Michael,

it's not Ruby, that expands your argument, but the shell. And
therefore you got no other chance than escaping the argument there.

This can be done using quotes or a backslash in front of each special
character
> ruby -e "puts ARGV" \*.txt

Best,

Gregor

On Jun 9, 11:39 am, Michael Jia <z...@yahoo.com> wrote:
> I want to pass in wildcard file names, and use it to match file names
> located in different directories. For example, *.txt will match file
> such as "my.txt", "you.txt", etc.
>
> However, I found out ruby intepreter automatically expands "*.txt"
> command argument to a array of filenames which matches that wildcard in
> the current directory.
>
> For example:
>
> C:\working>dir *.txt
>
> 05/10/2007 03:24 PM 46,101 config.txt
> 11/23/2004 11:54 AM 361 tips.txt
> 2 File(s) 46,462 bytes
>
> If you do,
>
> C:\working>ruby -e "puts ARGV" *.txt
> config.txt
> tips.txt
>
> Ruby converts string *.txt into the matching filenames and pass in the
> expanded array as the new argument.
>
> This *nice* trick sometime creates trouble.
>
> In my case, I want to use 'ARGV[0]' to match filenames in a different
> location. But ARGV[0] is not "*.txt" as my expected. It was changed by
> ruby. In fact, it is "config.txt" in this case.
>
> One way to correct it is to always ask user to use single-quoted string:
>
> C:\working>ruby -e "puts ARGV" '*.txt'
> *.txt
>
> --
> Posted viahttp://www.ruby-....

Michael Jia

6/9/2007 5:40:00 PM

Thanks you all for the reply.
I blog this thread in
http://zhifengjia.spaces.live.co...!5D88F9EA36578152!218.entry
Hopefully, it will appear in search engine's list to save ppl time.

Gregor Schmidt wrote:
> Hallo Michael,
>
> it's not Ruby, that expands your argument, but the shell. And
> therefore you got no other chance than escaping the argument there.
>
> This can be done using quotes or a backslash in front of each special
> character
>> ruby -e "puts ARGV" \*.txt
>
> Best,
>
> Gregor

--
Posted via http://www.ruby-....

Michael Jia

6/9/2007 6:19:00 PM

I did some further research on this topic. My win xp cmd shell seems
doesn't do wildcard expansion by itself.

C:\working>echo *.txt
*.txt

There are some posts saying the VC C runtime library is the one actually
does wildcard expansion. As seen here:
http://www.lyra.org/pipermail/scite-interest/2002-March/0...

A similar behavior in Java was also reported here,
http://bugs.sun.com/bugdatabase/view_bug.do?bug_...
http://mindprod.com/jgloss...
http://groups.google.com/group/comp.lang.java.programmer/browse_thread/thread/a6f188a2d521803e?hl=en&lr=&ie=UTF-8&oe=UTF-8&frame=right&seekm=01be589d%24dc827700%24baac72d1%40starga...

It seems to me that it is the ruby intepreter was linked to the runtime
library, namely, startargv.obj, then it gets the expansion for free. :)

Can someone familiar with ruby build please clarify?

--
Posted via http://www.ruby-....

Rob Biedenharn

6/9/2007 7:15:00 PM

On Jun 9, 2007, at 2:18 PM, Michael Jia wrote:

> I did some further research on this topic. My win xp cmd shell seems
> doesn't do wildcard expansion by itself.
>
> C:\working>echo *.txt
> *.txt
>
> There are some posts saying the VC C runtime library is the one
> actually
> does wildcard expansion. As seen here:
> http://www.lyra.org/pipermail/scite-interest/2002-March/0...
>
>
>
> A similar behavior in Java was also reported here,
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_...
> http://mindprod.com/jgloss...
> http://groups.google.com/group/comp.lang.java.p...
> browse_thread/thread/a6f188a2d521803e?
> hl=en&lr=&ie=UTF-8&oe=UTF-8&frame=right&seekm=01be589d%24dc827700%
> 24baac72d1%40stargate.sgi.net
>
> It seems to me that it is the ruby intepreter was linked to the
> runtime
> library, namely, startargv.obj, then it gets the expansion for
> free. :)
>
> Can someone familiar with ruby build please clarify?
>
> --
> Posted via http://www.ruby-....

rab:Users/rab $ mkdir tmp
rab:Users/rab $ cd tmp
rab:rab/tmp $ touch foo.txt bar.pdf baz.rb
rab:rab/tmp $ echo *.txt
foo.txt
rab:rab/tmp $ echo *.pdf
bar.pdf
rab:rab/tmp $ echo *.java
*.java
rab:rab/tmp $

It also depends what is in the directory at the time of the
expansion. If there are no files that match the glob pattern, the
shell (bash in this case) passes the argument as is (just as if it
had been '*.java').

rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.*
bar.pdf - baz.rb - foo.txt
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.txt
foo.txt
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.pdf
bar.pdf
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.java
*.java
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' b*
bar.pdf - baz.rb
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *f*
bar.pdf - foo.txt
rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' '*f*'
*f*

-Rob

Rob Biedenharn http://agileconsult...
Rob@AgileConsultingLLC.com

Michael Jia

6/9/2007 9:31:00 PM

I am using Windows XP "cmd" shell. What you described is true for unix
bash or C-shell.

C:\working>dir *.txt
Volume in drive C has no label.
Volume Serial Number is 5471-FCF7

Directory of C:\working

05/10/2007 03:24 PM 46,101 config.txt
11/23/2004 11:54 AM 361 tips.txt
2 File(s) 46,462 bytes
0 Dir(s) 32,580,259,840 bytes free

C:\working>echo *.txt
*.txt

That is why I think it is the ruby intepreter in Windows does the
expansion.

Regards
Michael

Rob Biedenharn wrote:
> On Jun 9, 2007, at 2:18 PM, Michael Jia wrote:
>
>>
>> It seems to me that it is the ruby intepreter was linked to the
>> runtime
>> library, namely, startargv.obj, then it gets the expansion for
>> free. :)
>>
>> Can someone familiar with ruby build please clarify?
>>
>> --
>> Posted via http://www.ruby-....
>
> rab:Users/rab $ mkdir tmp
> rab:Users/rab $ cd tmp
> rab:rab/tmp $ touch foo.txt bar.pdf baz.rb
> rab:rab/tmp $ echo *.txt
> foo.txt
> rab:rab/tmp $ echo *.pdf
> bar.pdf
> rab:rab/tmp $ echo *.java
> *.java
> rab:rab/tmp $
>
> It also depends what is in the directory at the time of the
> expansion. If there are no files that match the glob pattern, the
> shell (bash in this case) passes the argument as is (just as if it
> had been '*.java').
>
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.*
> bar.pdf - baz.rb - foo.txt
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.txt
> foo.txt
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.pdf
> bar.pdf
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.java
> *.java
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' b*
> bar.pdf - baz.rb
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *f*
> bar.pdf - foo.txt
> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' '*f*'
> *f*
>
> -Rob
>
> Rob Biedenharn http://agileconsult...
> Rob@AgileConsultingLLC.com

--
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Rob Biedenharn

6/9/2007 10:09:00 PM

In that case, you should run these two commands:

c:\working> ruby -e "puts ARGV.join(' - ')" *.txt

c:\working> ruby -e "puts ARGV.join(' - ')" "*.txt"

and they should produce the same output
(i.e., "config.txt - tips.txt" or "tips.txt - config.txt")
if the work is being done by the interpreter.

If one of them produces simply "*.txt" (probably the second), then
something different is going on.

-Rob

On Jun 9, 2007, at 5:30 PM, Michael Jia wrote:

> I am using Windows XP "cmd" shell. What you described is true for unix
> bash or C-shell.
>
>
> C:\working>dir *.txt
> Volume in drive C has no label.
> Volume Serial Number is 5471-FCF7
>
> Directory of C:\working
>
> 05/10/2007 03:24 PM 46,101 config.txt
> 11/23/2004 11:54 AM 361 tips.txt
> 2 File(s) 46,462 bytes
> 0 Dir(s) 32,580,259,840 bytes free
>
> C:\working>echo *.txt
> *.txt
>
>
> That is why I think it is the ruby intepreter in Windows does the
> expansion.
>
> Regards
> Michael
>
>
> Rob Biedenharn wrote:
>> On Jun 9, 2007, at 2:18 PM, Michael Jia wrote:
>>
>>>
>>> It seems to me that it is the ruby intepreter was linked to the
>>> runtime
>>> library, namely, startargv.obj, then it gets the expansion for
>>> free. :)
>>>
>>> Can someone familiar with ruby build please clarify?
>>>
>>> --
>>> Posted via http://www.ruby-....
>>
>> rab:Users/rab $ mkdir tmp
>> rab:Users/rab $ cd tmp
>> rab:rab/tmp $ touch foo.txt bar.pdf baz.rb
>> rab:rab/tmp $ echo *.txt
>> foo.txt
>> rab:rab/tmp $ echo *.pdf
>> bar.pdf
>> rab:rab/tmp $ echo *.java
>> *.java
>> rab:rab/tmp $
>>
>> It also depends what is in the directory at the time of the
>> expansion. If there are no files that match the glob pattern, the
>> shell (bash in this case) passes the argument as is (just as if it
>> had been '*.java').
>>
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.*
>> bar.pdf - baz.rb - foo.txt
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.txt
>> foo.txt
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.pdf
>> bar.pdf
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *.java
>> *.java
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' b*
>> bar.pdf - baz.rb
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' *f*
>> bar.pdf - foo.txt
>> rab:rab/tmp $ ruby -e 'puts ARGV.join(" - ")' '*f*'
>> *f*
>>
>> -Rob
>>
>> Rob Biedenharn http://agileconsult...
>> Rob@AgileConsultingLLC.com
>
>
> --
> Posted via http://www.ruby-....
>

Michael Jia

6/9/2007 10:17:00 PM

Rob, the result is:

C:\working>ruby -e "puts ARGV.join(' - ')" *.txt
config.txt - tips.txt

C:\working>ruby -e "puts ARGV.join(' - ')" "*.txt"
config.txt - tips.txt

Thanks
Michael

Rob Biedenharn wrote:
> In that case, you should run these two commands:
>
> c:\working> ruby -e "puts ARGV.join(' - ')" *.txt
>
> c:\working> ruby -e "puts ARGV.join(' - ')" "*.txt"
>
> and they should produce the same output
> (i.e., "config.txt - tips.txt" or "tips.txt - config.txt")
> if the work is being done by the interpreter.
>
> If one of them produces simply "*.txt" (probably the second), then
> something different is going on.
>
> -Rob

--
Posted via http://www.ruby-....

Rob Biedenharn

6/10/2007 2:54:00 AM

OK, then it look like your 'ruby' really is doing some form of
filename expansion for command-line arguments. However, not using
Windows myself, there's no way that I could help you more than this.
I do find it interesting though.

-Rob

On Jun 9, 2007, at 6:16 PM, Michael Jia wrote:

> Rob, the result is:
>
> C:\working>ruby -e "puts ARGV.join(' - ')" *.txt
> config.txt - tips.txt
>
> C:\working>ruby -e "puts ARGV.join(' - ')" "*.txt"
> config.txt - tips.txt
>
> Thanks
> Michael
>
> Rob Biedenharn wrote:
>> In that case, you should run these two commands:
>>
>> c:\working> ruby -e "puts ARGV.join(' - ')" *.txt
>>
>> c:\working> ruby -e "puts ARGV.join(' - ')" "*.txt"
>>
>> and they should produce the same output
>> (i.e., "config.txt - tips.txt" or "tips.txt - config.txt")
>> if the work is being done by the interpreter.
>>
>> If one of them produces simply "*.txt" (probably the second), then
>> something different is going on.
>>
>> -Rob

Rob Biedenharn http://agileconsult...
Rob@AgileConsultingLLC.com

comp.lang.ruby

Ruby wildcard command line argument auto expansion

Michael Jia

Michael Jia

Tim Hunter

Gregor Schmidt

Michael Jia

Michael Jia

Rob Biedenharn

Michael Jia

Rob Biedenharn

Michael Jia

Rob Biedenharn

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