Remove file name portion of local file URL - regex

Question

I have an HTML document which includes links to a hundred or so local files. I want to use either sed, awk or perl (in that preferred order) to remove the filename portion of the URL up to the last backslash in the URL. In the example below I'm only showing a portion of the HTML code forming the path of the local file.
Example:
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/SoftwarePackageName.dmg">
After Processing Example:
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/">
In testing I have tried different regular expression combinations to accomplish this however I'm only getting ".dmg" or it and everything to the left of .dmg and I really only want to remove the "SoftwarePackageName.dmg" portion. BTW In some cases it's "SoftwarePackageName.zip" and there may be a space in the "CompanyName" or "SoftwarePackageName.dmg" shown as "%20". I've also reviewed "Questions that may already have your answer" shown when creating this post.
EDIT: I appreciate the time taken to try and help and certainly understand the difficulty when due to policy I cannot provide more then the example I did and as such I'll just manually edit the html document. I've already taken to much of my time and others on this. Will just have to do more reading on regex for the next time. Thanks to all that contributed. :)

Answer 1

You could try the below sed command.
sed 's/\(<a href="[^."]*\/\)[^."\/]*\.[^."\/]*">/\1">/g' file

Answer 2

modded
I've deleted the previous sed regex (I have no way to test it).
Instead, I'm posting a expanded regex (verbose) that should help get you started.
# Unknown extension: (<a\s+[^>]*?href\s*=\s*(["'])[^>]*?/)([^/."'>]+\.[^/."'>]+)\2
# Known extension: (<a\s+[^>]*?href\s*=\s*(["'])[^>]*?/)([^/."'>]+\.dmg\b[^/."'>]*)\2
# Replacement: $1$2
( # (1 start), Tag and Url part to keep
<a \s+ [^>]*? href \s* = \s*
( ["'] ) # (2), Quote
[^>]*?
/ # End of directories
) # (1 end)
( # (3 start), Throw away filename
[^/."'>]+ # - Filename (not /."'> chars)
\. # - Dot
# - Extension and parameters
# ----------------------------
# Use one of these lines (but not both)
# Known extensions ->
#dmg \b [^/."'>]*
# Unknown extensions ->
[^/."'>]+
) # (3 end)
\2 # Backref to Quote
Sed should not use much of a different substitute structure s///g.
It might be the case that you have to escape parenthesis meta characters. But I think that's
it for this regex. These regex are in the raw state.
Here they are used in a sample Perl program. It could easily be done useing Perl from the command line.
use strict;
use warnings;
$/ = undef;
my $html = <DATA>; # slurp in the entire file
my $htmlcopy = $html;
$html =~ s|(<a\s+[^>]*?href\s*=\s*(["'])[^>]*?/)([^/."'>]+\.[^/."'>]+)\2|\1\2|g;
print "Replaced using Unknown extensions:\n", $html, "\n";
$htmlcopy =~ s|(<a\s+[^>]*?href\s*=\s*(["'])[^>]*?/)([^/."'>]+\.dmg\b[^/."'>]*)\2|\1\2|g;
print "Replace using Known extensions:\n", $htmlcopy, "\n\n";
__DATA__
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/SoftwarePackageName.dmg">
<a rel="nofollow" class="external text" href="http://www.ielts.org/researchers/analysis-of-test-data/">
<a rel="nofollow" class="external text" href="http://qiyas.sa/Sites/English/Tests/LanguageTests/Pages/Standardized-Test-for-English-Proficiency-(STEP).aspx">
<a rel="nofollow" class="external free" href="http://www.ielts.org/about_us.aspx">
<a href="/w/index.php?title=IELTS&redirect=no" title="IELTS">
<a href="/wiki/File:IELTS_logo.svg" class="image">
<a href="/w/index.php?title=International_English_Language_Testing_System&action=edit&section=1" title="Edit section: IELTS characteristics">
<a href="/w/index.php?title=Band_score&action=edit&redlink=1" class="new" title="Band score (page does not exist)">
<a href="/w/index.php?title=International_English_Language_Testing_System&action=edit&section=2" title="Edit section: IELTS test structure">
<a href="/wiki/University_of_St._Andrews" title="University of St. Andrews" class="mw-redirect">
<a rel="nofollow" class="external text" href="http://bandscore.ielts.org/search.aspx">
<a rel="nofollow" class="external text" href="http://www.bristol.ac.uk/university/governance/policies/admissions/language-requirements.html#toc05">
<a href="#cite_ref-11">
<a href="/wiki/Special:BookSources/1405833122" class="internal mw-magiclink-isbn">
Output >>
Replaced using Unknown extensions:
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/">
<a rel="nofollow" class="external text" href="http://www.ielts.org/researchers/analysis-of-test-data/">
<a rel="nofollow" class="external text" href="http://qiyas.sa/Sites/English/Tests/LanguageTests/Pages/">
<a rel="nofollow" class="external free" href="http://www.ielts.org/">
<a href="/w/" title="IELTS">
<a href="/wiki/" class="image">
<a href="/w/" title="Edit section: IELTS characteristics">
<a href="/w/" class="new" title="Band score (page does not exist)">
<a href="/w/" title="Edit section: IELTS test structure">
<a href="/wiki/" title="University of St. Andrews" class="mw-redirect">
<a rel="nofollow" class="external text" href="http://bandscore.ielts.org/">
<a rel="nofollow" class="external text" href="http://www.bristol.ac.uk/university/governance/policies/admissions/">
<a href="#cite_ref-11">
<a href="/wiki/Special:BookSources/1405833122" class="internal mw-magiclink-isbn">
Replace using Known extensions:
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/">
<a rel="nofollow" class="external text" href="http://www.ielts.org/researchers/analysis-of-test-data/">
<a rel="nofollow" class="external text" href="http://qiyas.sa/Sites/English/Tests/LanguageTests/Pages/Standardized-Test-for-English-Proficiency-(STEP).aspx">
<a rel="nofollow" class="external free" href="http://www.ielts.org/about_us.aspx">
<a href="/w/index.php?title=IELTS&redirect=no" title="IELTS">
<a href="/wiki/File:IELTS_logo.svg" class="image">
<a href="/w/index.php?title=International_English_Language_Testing_System&action=edit&section=1" title="Edit section: IELTS characteristics">
<a href="/w/index.php?title=Band_score&action=edit&redlink=1" class="new" title="Band score (page does not exist)">
<a href="/w/index.php?title=International_English_Language_Testing_System&action=edit&section=2" title="Edit section: IELTS test structure">
<a href="/wiki/University_of_St._Andrews" title="University of St. Andrews" class="mw-redirect">
<a rel="nofollow" class="external text" href="http://bandscore.ielts.org/search.aspx">
<a rel="nofollow" class="external text" href="http://www.bristol.ac.uk/university/governance/policies/admissions/language-requirements.html#toc05">
<a href="#cite_ref-11">
<a href="/wiki/Special:BookSources/1405833122" class="internal mw-magiclink-isbn">

Answer 3

Try this:
sed 's|\(<a href="file:///[^>]*/\).*">|\1">|g'
Demo:
$ sed 's|\(<a href="file:///[^>]*/\).*\.\(dmg\|zip\)">|\1">|g' <<EOF
> <a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/SoftwarePackageName.dmg">
> foo bar <a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/SoftwarePackageName.dmg"> baz quux
> EOF
<a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/">
foo bar <a href="file:///Volumes/VolumeName/Download/Mac%20Software/CompanyName/"> baz quux

Answer 4

First I want to say again how much I truly appreciate the time taken by those who tried to help! Secondly, it pains me to have to say that nothing that was presented worked in the real-world application and I, at the least, attribute that to you all not having the actual file I wanted to modify to work with and sorry I was not allowed to provide it. Yes your demos worked however unfortunately they were not at all representative of the actual html coding in the document and maybe because the "Generator" was "Cocoa HTML Writer" from a RTF Document this might have had something to do with it, just not sure at the moment. Even if I took just one complete line that included the Example code, placing it by itself in a file and then processing it nonetheless all solutions presented failed. I wish I could provide the file or take the time to figure out why in this real-world use it fails, however I can't.
Some background on the Document is when originally created as an RTF Document in TextEdit the FQP of the target file was included because the version of OS X would open the target file however in later versions of OS X it only opens Finder to the location of the target file. As such there is no longer a need to use the FQP to the target file just the path to its location. This actually makes it easier to update the RTF Document over time. At times this RTF Document is exported to an HTML Document to be modified and then saved as an RTF Document. As I mention earlier maybe the "Generator" being "Cocoa HTML Writer" from a RTF Document in TextEdit is in part to blame why processing failed with the proposed solutions.
Anyway the reason for my long winded reply is to put this issue in proper perspective and also explain how I resolved this issue. As I had previously mentioned I was just going to manually edit the file however after the generous help already presented I wanted to find some automated solutions and I did.
The primary constant was the Example code previously presented so focusing only on it here is the command line I used to process the file.
grep -o 'file:///[^"]*' Build_Out_Template.html | rev | cut -d / -f 1 | rev | while read LINE; do sed -i "s/${LINE}//" Build_Out_Template.html; done
Using "grep -o 'file:///[^"]*'" enabled me to extract just the target portion of the lines in the document. I piped it through rev to reverse the character order and piped it through cut which gave be only the portion up to the first slash in the reversed line (after the last slash in the original line) and then had to pipe it again through rev for obvious reasons. It was then piped through a loop where sed used a very simple instruction vs a complex regex using literally just the SoftwarePackageName.dmg etc. file name. While much more time was spent on this then manually editing the file nonetheless I took it as a challenge and will remember that sometimes the thinking out-side-the-box solution is faster and easier and I'll remember this for some other application if/when needed.
Thanks again to all who tried to help, it's truly appreciated.