Everyone who uses SVN knows that most repositories are set up to allow viewing of their contents via a web browser. For example, here's the trunk of WP Plugins SVN: http://plugins.svn.wordpress.org/ and here is the current trunk version of a specific file, let's say http://plugins.svn.wordpress.org/stats/trunk/readme.txt.

The Problem

However, what if you wanted to view a specific revision of a file or directory in your browser?

Let's say I wanted revision 100,000 of http://plugins.svn.wordpress.org/stats/trunk/readme.txt

Normally, on a command line, you'd do something like

svn co http://plugins.svn.wordpress.org/stats/trunk/readme.txt stats
cd stats;
svn up -r100000 readme.txt

or simply

svn export -r100000 http://plugins.svn.wordpress.org/stats/trunk/readme.txt

However, how would you do this in your browser? Trying something like ?r=100000 or ?revision=100000 parameters doesn't work.

The Solution

Here is the syntax to get a specific revision of a file or directory:

1. Take the root of the repository (in our case, http://plugins.svn.wordpress.org)
2. Append this string !svn/bc/REVISION_NUMBER right after the repository root and before the directory or file path.

Going back to our example:

• http://plugins.svn.wordpress.org/!svn/bc/100000/stats/

  shows the stats directory exactly as it was at revision 100,000 and

• http://plugins.svn.wordpress.org/!svn/bc/100000/stats/trunk/readme.txt

  shows our readme.txt at 100,000.

And that's how you do it, folks. Happy revisioning!

Update: this post is now sponsored by Wirefly Learn where you can find cell phone news and reviews, as well as comparisons and videos.

• How To Properly Set SVN svn:externals Property In SVN Command Line
• How To SVN Update All Your WordPress Plugins In One Go
• How To Check If The Local SVN Revision Is Up-To-Date
• Converting from CVS to SVN: Developer's Notes And Why SVN Is Better
• Beer Planet Upgraded To WordPress 2.5

Every time I have to deal with svn:externals in SVN, I forget the command line syntax. Every single damn time. Normally, I use SVN GUI clients, such as SmartSVN, which make it very simple to add an svn:externals property. But for command line, it always takes looking at 25 different sites on google, which are all incredibly unhelpful for this question for some reason. Trying "svn help propset" on the command line was bloated and equally useless.

So this time I needed to write it down and make sure everyone who needed help with svn:externals would find exactly what they need here. I hope this page will soon come up on top of all the unhelpful results on google for "propset svn:externals" and other related queries.

The Problem

I want to set a simple svn:externals property in one of my project's directories, lets say 'plugins' (talking about WordPress here). The outcome would be a directory called 'akismet' within 'plugins' that points to a remote svn url.

Various combinations of trying to do it produced pathetic results, like

svn propset svn:externals akismet http://plugins.svn.wordpress.org/akismet/trunk
svn: Setting property on non-local target 'http://plugins.svn.wordpress.org/akismet/trunk' needs a base revision

svn propset svn:externals . akismet http://plugins.svn.wordpress.org/akismet/trunk
svn: Error parsing svn:externals property on 'akismet': '.'

svn propset svn:externals akismet http://plugins.svn.wordpress.org/akismet/trunk akismet
svn: Setting property on non-local target 'http://plugins.svn.wordpress.org/akismet/trunk' needs a base revision

The Solution

Finally, thanks to this post, I found the right command:

svn propset svn:externals 'akismet http://plugins.svn.wordpress.org/akismet/trunk' .
property 'svn:externals' set on '.'

Note that dot at the end of the command and the quotes around the directory name and url.

Now commit via

svn commit

and then

svn up
Fetching external item into 'akismet'
A    akismet/akismet.gif
A    akismet/akismet.php
A    akismet/readme.txt
Updated external to revision 127962.
 
Updated to revision 16.

There, was it that hard, forum gurus and blog fiends?

Edit: in order to set multiple directory/url pairs in a single svn:externals property, you should put the individual dir/url pairs into a file (let's call it 'svn.externals'), like so

akismet http://svn.wp-plugins.org/akismet/trunk
all-in-one-seo-pack http://svn.wp-plugins.org/all-in-one-seo-pack/trunk

and then apply the property using

svn propset svn:externals -F svn.externals .

You should also just check in 'svn.externals' to easily keep track of it.

Let me briefly discuss some of the other methods first.

Limited

Using glob() (or <>, TODO verify) you can find files in a single directory, using only the limited shell wildcard support. For example,

1

my @files = glob("tmp*");

Boring

File::Find is the de facto standard for searching in Perl.

This method finds files that end in .pl in "." and "../SomeDir", following symlinks:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

#!/usr/bin/perl -w
 
use File::Find;
use Data::Dumper;
use File::Basename;
my @directories_to_search = (".", "../SomeDir");
my @file_list = ();
 
find(
  { wanted =>
    sub {
      if ( basename($File::Find::name) =~ /\.pl$/i )
      {
        push @file_list, $File::Find::name;
      }
    },
    follow => 1
  },
  @directories_to_search
);
print Dumper @file_list;

It works fine, except it's horribly ugly and boring. Let's have a look at something more fun.

The Fun And Elegant Way

File::Find::Rule. Just have a look at this beauty.

Just like above, find all .pl files in "." and "../SomeDir", following symlinks:

1
2

print Dumper (File::Find::Rule->name("*.pl")->file->extras({ follow => 1 })->
in(".", "../SomeDir"));

Same as above, except bypass .svn directories (shaves off a ton of time with a lot of directories):

1
2

print Dumper (File::Find::Rule->not(File::Find::Rule->directory->name('.svn')->
prune->discard)->name("*.pl")->file->extras({ follow => 1 })->in(".", "../SomeDir"));

Find all .log files that are older than 24 hours in "."

1
2
3

my $epoch_time_1_day_ago = time() - 60*60*24;
print Dumper (File::Find::Rule->file->name("*.log")->
mtime("<$epoch_time_1_day_ago")->in('.'));

Be sure to read the File::Find::Rule perldoc for more options and remember: have fun with your code!

Thanks to Perlbuzz and Andy Lester for pointing me to this library a few months ago.

• [Perl] How To Get The Path Of An Included Library (.pm), Regardless Of Current Directory
• FTPRush Cleanup Script
• Quick Perl Snippet: Finding If A File Has A Media Extension Using Regex
• How To Check If The Local SVN Revision Is Up-To-Date
• How To Sort Folders The Same Way As Files In Total Commander

I came up with 2, depending on how detailed the information needs to be, which I'm about to share in this post.

1. If you want exact file and directory names, you can run:

svn status -u

If any files need updating, you will see a * before the file name.

svn status wc
M     wc/bar.c
A  +   wc/qax.c

svn status -u wc
M            965    wc/bar.c
       *     965    wc/foo.c
A  +         965    wc/qax.c
Status against revision:   981

Or more verbose

svn status --show-updates --verbose wc
M            965       938 kfogel       wc/bar.c
       *     965       922 sussman      wc/foo.c
A  +         965       687 joe          wc/qax.c
             965       687 joe          wc/zig.c
Status against revision:   981

Parsing the output in Perl, for instance, should be trivial. A connection to the repository is established for this check, so be sure to catch in your code the times when such connection is not available.

2. If you only care about whether a specific directory needs to be updated or not, here's a quicker method:

svn info vs svn info -rHEAD

cd somedir;
svn info -r HEAD | grep -i "Last Changed Rev"
Last Changed Rev: 8544
svn info | grep -i "Last Changed Rev"
Last Changed Rev: 8531

If these numbers are not the same, an update is needed.

What can I be missing? Are there any other creative ways, or is svn update going to support dry-run? Feel free to leave a comment if you know something I don't.

• How To View A Specific SVN Revision In Your Browser
• How To SVN Update All Your WordPress Plugins In One Go
• Converting from CVS to SVN: Developer's Notes And Why SVN Is Better
• How To Show Hidden/Invisible Files In Total Commander, Both Locally And On An FTP Server
• How To Properly Set SVN svn:externals Property In SVN Command Line

1
2

cd YOUR_BLOG_ROOT/wp-content/plugins;
find . -maxdepth 1 -type d -exec svn up {} \;

What this command does is finds the top level directories in your WordPress plugins directory, then applies the "svn update" command to each, one by one.

The result is something like

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

Fetching external item into 'akismet'
A    akismet/readme.txt
Updated external to revision 50666.
 
Updated to revision 8094.
At revision 8094.
U    share-this/sharethis.php
Updated to revision 50666.
D    wp-postratings/postratings-admin-js.php
D    wp-postratings/postratings-usage.php
D    wp-postratings/postratings-js.php
A    wp-postratings/postratings-js-packed.js
U    wp-postratings/wp-postratings.php
A    wp-postratings/postratings-admin-js.js
U    wp-postratings/postratings-css.css
U    wp-postratings/postratings-options.php
A    wp-postratings/postratings-templates.php
U    wp-postratings/postratings-stats.php
U    wp-postratings/readme.html
A    wp-postratings/postratings-js.js
U    wp-postratings/wp-postratings.pot
U    wp-postratings/wp-postratings-widget.php
U    wp-postratings/postratings-uninstall.php
U    wp-postratings/postratings-admin-ajax.php
U    wp-postratings/wp-postratings.mo
U    wp-postratings/readme.txt
U    wp-postratings/postratings-manager.php
A    wp-postratings/postratings-admin-js-packed.js
Updated to revision 50666.
At revision 8094.
...

With such mass updating, of course, an incompatibility in one of the updates can break the whole blog. In my case, it happened to be the latest version of wp-sticky. I identified it by disabling wp-super-cache first, then disabling each updated plugin one by one. Once identified, I did the following:

1
2

cd wp-sticky
svn log | head

That showed me the latest commits by the author as well as the SVN revision numbers. I then used this information to revert one revision back by doing:

1

svn up -r 50489

The following command showed a diff of what exactly changed in that revision and broke everything:

1

svn diff -r50489:50490

Once everything was stable, I emailed the plugin author to tell him about the bug (heya, Lester). Be careful not to run 'svn up' on this directory again until the bug is fixed as it'll persistently update to the latest version.

• How To Properly Set SVN svn:externals Property In SVN Command Line
• How To View A Specific SVN Revision In Your Browser
• How To Check If The Local SVN Revision Is Up-To-Date
• How To: Disable/Block External HTTP Requests In WordPress
• How To Show Hidden/Invisible Files In Total Commander, Both Locally And On An FTP Server