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How To Display Just The HTTP Response Code In Command Line Curl

Artem Russakovskii — Fri, 11 Jun 2010 05:49:05 +0000

Today, I was looking for a quick way to see HTTP response codes of a bunch of urls. Naturally, I turned to the curl command, which I would usually use like this:

curl -IL "URL"

This command would send a HEAD request (-I), follow through all redirects (-L), and display some useful information in the end. Most of the time it's ideal:

curl -IL "http://www.google.com"
 
HTTP/1.1 200 OK
Date: Fri, 11 Jun 2010 03:58:55 GMT
Expires: -1
Cache-Control: private, max-age=0
Content-Type: text/html; charset=ISO-8859-1
Server: gws
X-XSS-Protection: 1; mode=block
Transfer-Encoding: chunked

However, the server I was curling didn't support HEAD requests explicitly. Additionally, I was really only interested in HTTP status codes and not in the rest of the output. This means I would have to change my strategy and issue GET requests, ignoring HTML output completely.

Curl manual to the rescue. A few minutes later, I came up with the following, which served my needs perfectly:

curl -sL -w "%{http_code} %{url_effective}\\n" "URL" -o /dev/null

Here is a sample of what comes out:

curl -sL -w "%{http_code} %{url_effective}\\n" "http://www.amazon.com/Kindle-Wireless-Reading-Display-Generation/dp/B0015T963C?tag=androidpolice-20" -o /dev/null
 
200 http://www.amazon.com/Kindle-Wireless-Reading-Display-Generation/dp/B0015T963C

Here, -s silences curl's progress output, -L follows all redirects as before, -w prints the report using a custom format, and -o redirects curl's HTML output to /dev/null.

Here are the other special variables available in case you want to customize the output some more:

url_effective
http_code
http_connect
time_total
time_namelookup
time_connect
time_pretransfer
time_redirect
time_starttransfer
size_download
size_upload
size_header
size_request
speed_download
speed_upload
content_type
num_connects
num_redirects
ftp_entry_path

Is there a better way to do this with curl? Perhaps, but this way offers the most flexibility, as I am in control of all the formatting.

Skype Extension For Firefox Is A Piece Of Crap – Leaks Memory, Hangs Firefox, Clubs Baby Seals

Artem Russakovskii — Thu, 12 Nov 2009 04:31:06 +0000

Introduction

Dear Skype,

you are great. You have the convenience of a nearby, well, convenience store and the UI that is acceptable to even an Apple fanboy (I'm not one, I'm just saying).

Skype also has a Firefox extension which finds all pieces of text that resemble phone numbers on web pages you are visiting and converts them into clickable Skype buttons . One click and you're dialing the number. The premise is great but the execution… When it comes to your Firefox extension, Skype – you suck. You really suck.

The Problem Bullshit

So what makes me say these mean things? Is it the fact that when simply searching Google for "skype firefox", one finds mostly blog posts and references to major fail? Or is it the fact that MozillaZine's Problematic Extensions page lists Skype as one of the buggiest?

Well, yes. Those are great, aren't they? However, what really prompted me to write this post is my own experience with this extension.

As I am getting into Android development nowadays, I read the Android dev guide quite a lot. Thus, it was no surprise that yesterday I was happily reading the page about Handling UI Events. What was a surprise, however, is that when I clicked over to the View API reference page (in case that page ever changes for documentation reasons, I also saved it here), my Firefox went into a painful agony and exploded in a few minutes.

What the fudgemonkeys? Let's do this again and watch the Process Explorer.

This is what we call a memory leak – a prime example at that. In the screenshot above, the CPU usage spikes to 100% (shown as 50% because it's a dual core CPU), Firefox's memory usage jumps to around 2GB from 100MB, in 500MB/s increments. Finally, at 5GB total system memory consumption, either the OS kicks in or some major swapping starts to occur – I'm not sure which of the two is happening exactly but you can see it when the green CPU marker gets overtaken by the red one.

As I have a large number of extensions installed, I was dreading the next step: disabling them until the culprit was found. Ugh…

Sure enough, after about half an hour of starting Firefox, observing the memory leak, killing, and restarting it, I narrowed it down to the Skype extension. Somebody at Skype needs to fess up. And here's the kicker – it only exposes the memory leak in the following configuration:

If you turn number highlighting on – it's fine. If you turn name highlighting off – it's fine. But if you turn number highlighting off but leave name highlighting on – major fail.

The Conclusion

So where am I going with all this? Here is the summary:

somebody at Skype doesn't know how to program
this is the worst memory leak in a Firefox extension I've ever seen
this extension is notorious for its crashes, bugs, and memory leaks
keep using this extension if you're
- a masochist
- need to perform burn-in tests for your CPU or RAM

Have you had problems with the Skype extension? If so, share in the comments.

Hidden Features Of Perl, PHP, Javascript, C, C++, C#, Java, Ruby, Python, And Others [Collection Of Incredibly Useful Lists]

Artem Russakovskii — Sun, 21 Jun 2009 19:38:56 +0000

Introduction

StackOverflow is an amazing site for coding questions. It was created by Joel Spolsky of joelonsoftware.com, Jeff Atwood of codinghorror.com, and some other incredibly smart guys who truly care about user experience. I have been a total fan of SO since it went mainstream and it's now a borderline addiction (you can see my StackOverflow badge on the right sidebar).

The Story

Update 6/21/09: This server is currently under very heavy load (10-200), even with caching plugins enabled. Please bear with me as I try to resolve the situation.

Feel free to bookmark this page and return to it later when the fires have been put out.

Update 06/21/09: I think I've got the situation under control now. The load is between 0 and 3 now and pages load relatively fast. I will be posting about the getting redditted/delicioused experience later.

Update 06/23/09: Added jQuery, Greasemonkey, Ruby on Rails, and Objective-C, broke databases into their own section, and sorted everything alphabetically.

Update 06/23/09: Added Scala, Lua, TCL, F#, Regex, and HTTP.

Update 07/21/09: Added ActionScript3/Flex, Erlang, PL/SQL, Silverlight, VBA, VHDL, WPF/XAML.

Update 10/24/09: Added Flash development/language/IDE, Emacs, Xpath/Xslt, Spring framework.

Update 01/18/10: Added Android (asked by yours truly), Qt, Django, Windows.Forms, R, Lisp, x86 assembly, Grails.

So, one day someone at StackOverflow started a "Hidden features of" post about a famous language (I don't feel like finding out which one was first exactly), and it turned out to be so popular that other posts in the same series started popping up.

Such questions were quickly turned into community wikis, for the purposes of harvesting and organizing information coming from the best developers on the planet and voted by users of the site. There are literally hundreds of answers, sorted by votes.

The Hidden Features series is great for people who are new to a certain language. It shows the ropes and tricks, all in one place, in the most concise manner possible. Even pros oftentimes find features of their favorite language that they'd never heard about.

beer planet » code

How To Display Just The HTTP Response Code In Command Line Curl

Skype Extension For Firefox Is A Piece Of Crap – Leaks Memory, Hangs Firefox, Clubs Baby Seals

Introduction

The Problem Bullshit

The Conclusion

Hidden Features Of Perl, PHP, Javascript, C, C++, C#, Java, Ruby, Python, And Others [Collection Of Incredibly Useful Lists]

Introduction

The Story

Hidden Features Of

Programming Languages

Databases

Mobile

Other

Hidden features of Bash – also see my bash cheatsheet.