How do I cd to a directory starting with a hypen (-)?
# /var/folders/*whatever*/ has a folder named '-Tmp-'
$ ls
-Caches-/ -Tmp-/
# lets try and CD there
$ cd -Tmp-
-bash: cd: -T: invalid option
cd: usage: cd [-L|-P] [dir]
# or maybe make sure its a directory
$ cd -Tmp-/
-bash: cd: -T: invalid option
cd: usage: cd [-L|-P] [dir]
# try and escape the first -
$ cd \-Tmp-
-bash: cd: -T: invalid option
cd: usage: cd [-L|-P] [dir]
# quote it
$ cd '-Tmp-'
-bash: cd: -T: invalid option
cd: usage: cd [-L|-P] [dir]
# double quote it
$ cd "-Tmp-"
-bash: cd: -T: invalid option
cd: usage: cd [-L|-P] [dir]
# escape it in the quotes
$ cd '\-Tmp-'
-bash: cd: \-Tmp-: No such file or directory
# escape it in the double quotes
$ cd "\-Tmp-"
-bash: cd: \-Tmp-: No such file or directory
# try a "./" hack
$ cd ./-Tmp-/
$ echo "WHOOP"
WHOOP
(Source: gist.github.com)
For the past year we’ve all been happy.
rake was stable at 0.8.7
You could run
rake
In any project and it’d just work.
But now, with the release of rake 0.9.0, sometimes we get this
RudiMac:3rdhome matthew$ rake
rake aborted!
You have already activated rake 0.9.0,
but your Gemfile requires rake 0.8.7.
Consider using bundle exec.
(See full trace by running task with --trace)
And there’s a simple solution.
#!/usr/bin/env bash
if [ -f Gemfile ]; then
bundle exec rake $@
else
rake $@
fi
Either copy and paste the gist into an executable (~/bin/rage maybe)
Or follow these instructions;
git clone git://gist.github.com/1003927.git ~/rage-gist
mkdir ~/bin
cp ~/rage-gist/rage ~/bin/
chmod a+x ~/bin/rage
As long as ~/bin is in your path you should be set.
rage db:migrate test --trace
BOOM!
So I just committed to master
commit b17a1fbe8f5d59c24a1f2bb50c9905f8345263f5a
Author: Jeffrey Giraffe <Jeffrey.T.Giraffe@gmail.com>
Date: Wed May 18 18:22:22 2011 +0800
Started work on an exciting new feature.
But I shouldn’t have.
All features should be in a “feature branch”
How do I move my commit onto a different branch?
Luckily I haven’t pushed yet.
So just start my “feature branch” right now.
git checkout -b exciting-new-feature
git push origin exciting-new-feature
Then go back to master, and undo the commit
git checkout master
git reset --hard HEAD~1
Or if there are 3 commits
git reset --hard HEAD~3
Of course, if I’ve already pushed this would be a little more tricky.
I suggest (for verbosity) you shouldn’t try to do anything fancy.
Just revert it
git revert HEAD
and humbly explain why
Revert "Started work on an exciting new feature."
This commit is not ready to be on master yet,
and has been moved onto the branch "exciting-new-feature"
This reverts commit b17a1fbe8f5d59c24a1f2bb50c9905f8345263f5a.
Boom!
So I have some tests for geocoding, that I want to be run live.
test "geocoding" do
record = Address.create!(:address => "Pretty Cottage, Winding Road, Beautiful Country")
assert_equal 51.59011, record.latitude
assert_equal -2.995398, record.longitude
end
Of course, these will fail when there’s no internet.
My choices;
- mock the geocoding API
- let them fail
- only run this test when there’s internet
I chose the latter.
How do I know I have internet connection?
Can I ping google?
system "ping -q -c 1 -t 1 google.com 1> /dev/null" #=> true / false
Complication!
the above works on OSX (where -t1 sets a timeout of 1 second)
but on Linux -t has a different meaning, and -w1 sets the timeout
Compromise: ignore timeouts for the moment
system "ping -q -c 1 google.com 1> /dev/null" #=> true / false
Stick this in a method
def requires_internet!
if can_ping_google?
yield
else
flunk "this test needs to be run when there is internet"
end
end
Now incorporate this into our test.
test "geocoding" do
requires_internet! do
record = Address.create!(:address => "Pretty Cottage, Winding Road, Beautiful Country")
assert_equal 50.0, record.latitude
assert_equal -0.3, record.longitude
end
end
Done.
Here’s the gist. Fork it and make it better!
Yes that’s right.
I broke RubyGems.org.
No April Fools Joke! (although this did happen after midnight HKT)
… I’ve hidden the cause so they have a chance to fix it…
… but its a unicode thing …
I packaged it with gem-this, and did a `gem push` it turned out http://rubygems.org was down!
I went to bed hoping it would go away, and woke up on April 1st morning to find an email;
Hi Matthew! Looks like you just found a bug that made our homepage unhappy.
=> #<Rubygem id: 39928, name: …,
I straight up deleted that gem. Can you send or paste the gem/gemspec
with that so we can make sure this doesn’t happen again?
-Nick
So, there you go!
Rubygems.org currently can’t support unicode gem names!
I hoped it’d be as simple as a `brew install postgresql`
And it almost was.
But…
RudiMac:merlot matthew$ tail -f /usr/local/var/postgres/server.log
FATAL: database files are incompatible with server
DETAIL: The data directory was initialized by PostgreSQL version 8.4, which is not compatible with this version 9.0.3.
How do I fix the data files?
Turns out there is a `pg_update` method to do this for you.
But it requires a bit of manual work.
# First of all stop the server
launchctl unload -w ~/Library/LaunchAgents/org.postgresql.postgres.plist
# backup the old data directory
mv /usr/local/var/postgres /usr/local/var/postgres.old
# now create a fresh postgres 9 data directory
initdb /usr/local/var/postgres
Now we’re ready to do the upgrade.
pg_upgrade -d /usr/local/var/postgres.844/ -D /usr/local/var/postgres -b /usr/local/Cellar/postgresql/8.4.4/bin -B /usr/local/Cellar/postgresql/9.0.3/bin
...
Upgrade complete
----------------
Boom Ting
Now just add the launch control back in and we’re off.
cp /usr/local/Cellar/postgresql/9.0.3/org.postgresql.postgres.plist ~/Library/LaunchAgents
launchctl load -w ~/Library/LaunchAgents/org.postgresql.postgres.plist
I was shocked today to find I’d introduced a bug.
It manifested itself like this;
This might seem ok.
Except the “Number of repayments” is set by javascript as;
the number of days interest
less the number of days before repayment begins
Looking at the dates, the “number of days before repayment begins” should be 2.
But the difference is -6.
Something is wrong.
And the answer is here;
var date_from_field = function(field_id) {
var field = $(“#”+field_id);
var year, month, day;
var date_bits = field.val().split(“-“);
var year = parseInt(date_bits[0]);
var month = parseInt(date_bits[1]);
var day = parseInt(date_bits[2]);
return new Date(year,month-1,day);
};
I take a date field
<input type=”date” value=”2010-12-08” />
I grab the value
“2010-12-08”
I split it into year, month, and day
[“2010”, “12”, “08”]
I turn them into integers
[2010, 12, 0]
Then I make them into a date
new Date(2010,11,0); // Tue Nov 30 2010
No problem!
Except…
“2010-12-08” != Tue Nov 30 2010
The problem is
parseInt(“08”) == 0
parseInt(“08”, 10) == 8
“08” is 0 in octal
Always use parseInt(something, 10)
Bundler is still a work in progress, so you can expect things to change.
One of these things that has changed between Bundler 1.0.6 and Bundler 1.0.7 is that the “METADATA” field has been removed.
So I’m running Bundler 1.0.7 (with no METADATA) and my colleagues are running 1.0.6 (with METADATA)
I keep getting this diff.
$ git diff Gemfile.lock
diff —git a/Gemfile.lock b/Gemfile.lock
index ec585b3..ee6ba65 100644
—- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -221,3 +221,7 @@ DEPENDENCIES
whitelist_mail_proxy
will_paginate!
zipruby
-
-
-METADATA
- version: 1.0.6
I want bundler to manage itself
# self-referential
gem “bundler”, “>=1.0.7”
And it works
but the message is a bit unpretty
RudiMac:merlot matthew$ bundle install
Fetching source index for http://rubygems.org/
Bundler could not find compatible versions for gem “bundler”:
In Gemfile:
bundler (>= 1.0.7)
Current Bundler version:
bundler (1.0.6)
Your version of Bundler is older than the one requested by the Gemfile.
Perhaps you need to update Bundler by running `gem install bundler`.
I need to use “gem install”?
I wonder if we can patch bundler to install itself.
I recommend you always have a “>= x.x.x”… just for jokes try setting
gem “bundler”, “1.0.6”
I realised I can write even more Ruby in Chinese.
The only gotchas are;
- don’t attempt to use Chinese punctuation （”‘＝＋－，。）
- it doesn’t recognise Chinese as uppercase, so you can’t start a class or Constant name with a chinese character
So here is my code.
# encoding: utf-8
class C动物
def initialize(名字)
@名字 = 名字
end
attr_reader :名字
def 朋友?(别的)
true
end
def 吃了?
false
end
end
class C狗 < C动物
def 朋友?(别的)
!别的.is_a?(C马泰)
end
end
class C人 < C动物
end
class C马泰 < C人
def 吃了?(别的)
别的.is_a?(C狗)
end
end
我=C马泰.new("马泰")
puts "我的名字是#{我.名字}"
她=C人.new("张学敏")
puts "她的名字是#{她.名字}"
狗=C狗.new("阿财")
puts "狗的名字是#{狗.名字}"
puts "狗是我的朋友吗？#{我.朋友?(狗)}"
puts "我是狗的朋友吗？#{狗.朋友?(我)}"
puts "狗吃了我吗？#{狗.吃了?(我)}"
puts "我吃了狗吗？#{我.吃了?(狗)}"
See the full gist at https://gist.github.com/711563
Maybe I should write a plugin for rails.
