Regexp to extract a href tags

[DEXTER]

Hi
I would like to extract all the anchor tags in a web page

webpage , err := ioutil.ReadAll(res.Body)
page := string(webpage);

const pattern string = "([<a.*\\/a>]+)"
r := regexp.MustCompile(pattern)
result := r.FindAllString(page ,-1)

This prints
< > < a a a > < a > < a > < a / a > < > a a</ > < a a > < a a a a . a
a a a a a a . > < a a a a a a a a a a a a a a a a > < / a a > // a . .
a a a </ > < / a a > //

I would like to get an array of strings of all the anchor tags

Is there any documentation on RegExp something similar to what php
maintains

Thanks
Dexter

[Chris Broadfoot]

Try this, perhaps:

http://code.google.com/p/go-html-transform/

I would strongly recommend against parsing HTML5 with regular expressions.

[Archos]

Use the package [html][1].

import (
"bytes"
"exp/html"
)

var (
anchorTag = []byte{'a'}
)

tkzer := html.NewTokenizer(page)

for {
switch tkzer.Next() {
case html.ErrorToken:
// HANDLE ERROR

case html.StartTagToken:
tag, hasAttr := tkzer.TagName()
if hasAttr && bytes.Equal(anchorTag, tag) { // a
// HANDLE ANCHOR
}
}
}

[1]: http://weekly.golang.org/pkg/exp/html/

[Archos]

On May 19, 5:42 pm, Archos <raul....@sent.com> wrote:
> Use the package [html][1].
>
>         import (
>                 "bytes"
>                 "exp/html"
>         )
>
>         var (
>                 anchorTag = []byte{'a'}
>         )
>
>         tkzer := html.NewTokenizer(page)
>
>         for {
>                 switch tkzer.Next() {
>                 case html.ErrorToken:
>                         // HANDLE ERROR
>
>                 case html.StartTagToken:
>                         tag, hasAttr := tkzer.TagName()
>                         if hasAttr && bytes.Equal(anchorTag, tag) { // a
>                                 // HANDLE ANCHOR
>                         }
>                 }
>         }
>
> [1]:http://weekly.golang.org/pkg/exp/html/

And to match only the href tags:

var (
anchorTag = []byte{'a'}

hrefTag = []byte("href")
httpTag = []byte("http")
)

// * * *
// HANDLE ANCHOR
key, val, _ := tkzer.TagAttr()
if bytes.Equal(hrefTag, key) && bytes.HasPrefix(val, httpTag) { //
href, http(s)
// HREF TAG
}

[Rodrigo Moraes]

On May 19, 11:08 am, Chris Broadfoot wrote:
> I would strongly recommend against parsing HTML5 with regular expressions.

Here's a classic:
http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454

-- rodrigo

[Mack Johnson]

[1]: http://weekly.golang.org/pkg/exp/html/

How do get this package? It is not in my go distribution.  Is there a way to get it using the goinstall command? 

[Patrick Mylund Nielsen]

The best way is to install Go (weekly) from source:
http://golang.org/doc/install/source

(exp packages aren't available in the stable distribution)

[Brad Fitzpatrick]

No, don't install weekly.  That's older than go1 itself.

Just copy the files somewhere.

[Peter Bourgon]

I've cloned this particular package,

go get -v github.com/peterbourgon/exp-html

On Sat, May 19, 2012 at 7:49 PM, Mack Johnson <johnma...@ymail.com> wrote:

[Patrick Mylund Nielsen]

Oh, whoops. Missed that this stopped.

[Patrick Mylund Nielsen]

Perhaps http://golang.org/doc/install/source should be updated? It
still refers to weekly being updated "about once per week." Or is it
the plan to resume these updates?

On Sun, May 20, 2012 at 2:32 PM, Patrick Mylund Nielsen

[Carlos Castillo]

Optionally you could go get the original:

go get code.google.com/p/go/src/pkg/exp/html

The upside is that go get -u will always be up to date, the downside is that you now have the entire go source in your GOPATH under code.google.com/p/go/

[Peter S]

Optionally you could go get the original:
go get code.google.com/p/go/src/pkg/exp/html

AFAIK this doesn't work with the stable versions of go (go1, go1.0.1), at least it definitely doesn't work for me (go1.0.1 binary distribution on linux/64). IIUC "go get" uses the "go version" (i.e. go1, go1.0.1) as the tag when pulling the sources, and for those tags the exp packages are excluded. (Which is probably the main reason people have been setting up external mirrors in the first place.)

Peter

[Carlos Castillo]

Ah, you are right.

--
Carlos Castillo