[gentoo-user] Is grep broken?

[gentoo-user] Is grep broken?

[Peter Humphrey]

Hello list,

Can anyone explain this to me?

$ /bin/grep -r hmenu *html
index.html:                     <div id="hmenu">
master.html:                    <div id="hmenu">
pictures.html:                  <div id="hmenu">

$ /bin/grep -r hmenu pages/*html
pages/community.html:                   <div id="hmenu">
pages/contacts.html:                    <div id="hmenu">
pages/history.html:                     <div id="hmenu">
pages/music.html:                       <div id="hmenu">
pages/news.html:                        <div id="hmenu">
pages/people.html:                      <div id="hmenu">
pages/pictures.html:                    <div id="hmenu">

Grep is clearly disobeying the recursion command. I started noticing this a 
few days ago, and it's making maintenance of this directory hard work.

-- 
Rgds
Peter

Re: [gentoo-user] Is grep broken?

[Alan McKinnon]

On Wednesday 01 July 2009 16:30:26 Peter Humphrey wrote:
> Hello list,
>
> Can anyone explain this to me?
>
> $ /bin/grep -r hmenu *html
> index.html:                     <div id="hmenu">
> master.html:                    <div id="hmenu">
> pictures.html:                  <div id="hmenu">
>
> $ /bin/grep -r hmenu pages/*html
> pages/community.html:                   <div id="hmenu">
> pages/contacts.html:                    <div id="hmenu">
> pages/history.html:                     <div id="hmenu">
> pages/music.html:                       <div id="hmenu">
> pages/news.html:                        <div id="hmenu">
> pages/people.html:                      <div id="hmenu">
> pages/pictures.html:                    <div id="hmenu">
>
> Grep is clearly disobeying the recursion command. I started noticing this a
> few days ago, and it's making maintenance of this directory hard work.

You equally clearly do not understand how recursion works. You told it to grep 
through all the html files starting from pages/ and it did so.

You did not tell it to start from pages/.. so why do you think it should do 
so?

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Is grep broken?

[Patrick Holthaus]

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On Wednesday 01 July 2009 16:30:26 Peter Humphrey wrote:
> Hello list,
>
> Can anyone explain this to me?
>
> $ /bin/grep -r hmenu *html
> index.html:                     <div id="hmenu">
> master.html:                    <div id="hmenu">
> pictures.html:                  <div id="hmenu">

The star is evaluated /before/ grep is executed. Therefore, only files that are 
ending with html are searched recursively. If you had placed the files in a 
directory called blablahtml, then grep would have searched there.

> $ /bin/grep -r hmenu pages/*html
> pages/community.html:                   <div id="hmenu">
> pages/contacts.html:                    <div id="hmenu">
> pages/history.html:                     <div id="hmenu">
> pages/music.html:                       <div id="hmenu">
> pages/news.html:                        <div id="hmenu">
> pages/people.html:                      <div id="hmenu">
> pages/pictures.html:                    <div id="hmenu">
>
> Grep is clearly disobeying the recursion command. I started noticing this a
> few days ago, and it's making maintenance of this directory hard work.

No, you just did not tell it to search in the the directory pages. :)

HTH
Patrick


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Re: [gentoo-user] Is grep broken?

[Peter Humphrey]

On Wednesday 01 July 2009 15:37:15 Patrick Holthaus wrote:

> No, you just did not tell it to search in the the directory pages. :)

I'm sure it used to work the way I want it to. I think I see insanity 
looming...

-- 
Rgds
Peter

Re: [gentoo-user] Is grep broken?

[Neil Bothwick]

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On Wed, 1 Jul 2009 15:47:52 +0100, Peter Humphrey wrote:

> > No, you just did not tell it to search in the the directory
> > pages. :)  
> 
> I'm sure it used to work the way I want it to. I think I see insanity 
> looming...

It does work the way you want it to, just not the way you told it to :)


-- 
Neil Bothwick

Multitasking: Reading in the bathroom.

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[gentoo-user] Re: Is grep broken?

[Grant Edwards]

On 2009-07-01, Peter Humphrey <peter@humphrey.ukfsn.org> wrote:

> Can anyone explain this to me?
>
> $ /bin/grep -r hmenu *html
> index.html:                     <div id="hmenu">
> master.html:                    <div id="hmenu">
> pictures.html:                  <div id="hmenu">

The shell expands *html to a list of html files in the current
directory.  IOW, you explicitly gave grep a list of html files
to search.  The -r flag does nothing in that case.

You appear to want to search all files underneath the current
directory who's name matches the shell glob pattern "*html".
If that's the case, then what you meant to say was:

  find . -name '*html' | xargs grep hmenu

> $ /bin/grep -r hmenu pages/*html
> pages/community.html:                   <div id="hmenu">
> pages/contacts.html:                    <div id="hmenu">
> pages/history.html:                     <div id="hmenu">
> pages/music.html:                       <div id="hmenu">
> pages/news.html:                        <div id="hmenu">
> pages/people.html:                      <div id="hmenu">
> pages/pictures.html:                    <div id="hmenu">
>
> Grep is clearly disobeying the recursion command. I started noticing this a 
> few days ago, and it's making maintenance of this directory hard work.

Again, you gave grep an explicit list of files to search, so
the -r option doesn't do anything.  In this case, it's not
obvious what you intend, so I'll refrain from guessing.

-- 
Grant Edwards                   grante             Yow! I want to kill
                                  at               everyone here with a cute
                               visi.com            colorful Hydrogen Bomb!!

Re: [gentoo-user] Is grep broken?

[Keith Dart]

On Wed, 1 Jul 2009 15:47:52 +0100
Peter Humphrey <peter@humphrey.ukfsn.org> wrote:

> I'm sure it used to work the way I want it to. I think I see insanity 
> looming...

On a side note, you might also want to investigate "sgrep", since
you're grepping inside html files.



-- 
-- --------------------
Keith Dart
<keith@dartworks.biz>
=======================

Re: [gentoo-user] Is grep broken?

[Peter Humphrey]

On Wednesday 01 July 2009 19:03:34 Keith Dart wrote:
> On Wed, 1 Jul 2009 15:47:52 +0100
>
> Peter Humphrey <peter@humphrey.ukfsn.org> wrote:
> > I'm sure it used to work the way I want it to. I think I see insanity
> > looming...
>
> On a side note, you might also want to investigate "sgrep", since
> you're grepping inside html files.

Thanks for the hint. I'm installing it now. Man grep didn't mention it in 
the "see also" section. Apropos didn't mention it either, since it wasn't 
installed at the time  :-(

-- 
Rgds
Peter

Re: [gentoo-user] Is grep broken?

[Carlos]

Peter Humphrey a écrit :
> Hello list,
> 
> Can anyone explain this to me?
> 
> $ /bin/grep -r hmenu *html
> index.html:                     <div id="hmenu">
> master.html:                    <div id="hmenu">
> pictures.html:                  <div id="hmenu">
> 
> $ /bin/grep -r hmenu pages/*html
> pages/community.html:                   <div id="hmenu">
> pages/contacts.html:                    <div id="hmenu">
> pages/history.html:                     <div id="hmenu">
> pages/music.html:                       <div id="hmenu">
> pages/news.html:                        <div id="hmenu">
> pages/people.html:                      <div id="hmenu">
> pages/pictures.html:                    <div id="hmenu">
> 
> Grep is clearly disobeying the recursion command. I started noticing this a 
> few days ago, and it's making maintenance of this directory hard work.
> 

As other have pointed out, the behaviour of grep is correct in the 
examples above.

You could use the --include directive :

grep -r --include=*html hmenu .

Basically, this tells grep to recursive look for hmenu in any files that 
include *html starting from the current directory (* would be equally 
fine if you didn't want to search in 'hidden' dot directories).

Regards,
Carlos

Re: [gentoo-user] Is grep broken?

[Peter Humphrey]

On Thursday 02 July 2009 08:23:19 Carlos wrote:

> You could use the --include directive :
>
> grep -r --include=*html hmenu .

Nice idea - thanks.

-- 
Rgds
Peter