Why curl defaults to stdout

(Recap: I founded the curl project, I am still the lead developer and maintainer)

When asking curl to get a URL it’ll send the output to stdout by default. You can of course easily change this behavior with options or just using your shell’s redirect feature, but without any option it’ll spew it out to stdout. If you’re invoking the command line on a shell prompt you’ll immediately get to see the response as soon as it arrives.

I decided curl should work like this, and it was a natural decision I made already when I worked on the predecessors during 1997 or so that later would turn into curl.

On Unix systems there’s a common mantra that “everything is a file” but also in fact that “everything is a pipe”. You accomplish things on Unix by piping the output of one program into the input of another program. Of course I wanted curl to work as good as the other components and I wanted it to blend in with the rest. I wanted curl to feel like cat but for a network resource. And cat is certainly not the only pre-curl command that writes to stdout by default; they are plentiful.

And then: once I had made that decision and I released curl for the first time on March 20, 1998: the call was made. The default was set. I will not change a default and hurt millions of users. I rather continue to be questioned by newcomers, but now at least I can point to this blog post! 🙂

About the wget rivalry

cURLAs I mention in my curl vs wget document, a very common comment to me about curl as compared to wget is that wget is “easier to use” because it needs no extra argument in order to download a single URL to a file on disk. I get that, if you type the full commands by hand you’ll use about three keys less to write “wget” instead of “curl -O”, but on the other hand if this is an operation you do often and you care so much about saving key presses I would suggest you make an alias anyway that is even shorter and then the amount of options for the command really doesn’t matter at all anymore.

I put that argument in the same category as the people who argue that wget is easier to use because you can type it with your left hand only on a qwerty keyboard. Sure, that is indeed true but I read it more like someone trying to come up with a reason when in reality there’s actually another one underneath. Sometimes that other reason is a philosophical one about preferring GNU software (which curl isn’t) or one that is licensed under the GPL (which wget is) or simply that wget is what they’re used to and they know its options and recognize or like its progress meter better.

I enjoy our friendly competition with wget and I seriously and honestly think it has made both our projects better and I like that users can throw arguments in our face like “but X can do Y”and X can alter between curl and wget depending on which camp you talk to. I also really like wget as a tool and I am the occasional user of it, just like most Unix users. I contribute to the wget project well, both with code and with general feedback. I consider myself a friend of the current wget maintainer as well as former ones.

Keyboard key frequency

A while ago I wrote about my hunt for a new keyboard, and in my follow-up conversations with friends around that subject I quickly came to the conclusion I should get myself better analysis and data on how I actually use a keyboard and the individual keys on it. And if you know me, you know I like (useless) statistics.

Func KB-460 keyboardSo, I tried out the popular and widely used Linux key-logger software ‘logkeys‘ and immediately figured out that it doesn’t really support the precision and detail level I wanted so I forked the project and modified the code to work the way I want it: keyfreq was born. Code on github. (I forked it because I couldn’t find any way to send back my modifications to the upstream project, I don’t really feel a need for another project.)

Then I fired up the logging process and it has been running in the background for a while now, logging every key stroke with a time stamp.

Counting key frequency and how it gets distributed very quickly turns into basically seeing when I’m active in front of the computer and it also gave me thoughts around what a high key frequency actually means in terms of activity and productivity. Does a really high key frequency really mean that I was working intensely or isn’t that purpose more a sign of mail sending time? When I debug problems or research details, won’t those periods result in slower key activity?

In the end I guess that over time, the key frequency chart basically says that if I have pressed a lot of keys during a period, I was working on something then. Hours or days with a very low average key frequency are probably times when I don’t work as much.

The weekend key frequency is bound to be slightly wrong due to me sometimes doing weekend hacking on other computers where I don’t log the keys since my results are recorded from a single specific keyboard only.

Conclusions

So what did I learn? Here are some conclusions and results from 1276614 keystrokes done over a period of the most recent 52 calendar days.

I have a 105-key keyboard, but during this period I only pressed 90 unique keys. Out of the 90 keys I pressed, 3 were pressed more than 5% of the time – each. In fact, those 3 keys are more than 20% of all keystrokes. Those keys are: <Space>, <Backspace> and the letter ‘e’.

<Space> stands out from all the rest as it has been used more than 10%.

Only 29 keys were used more than 1% of the presses, giving this a really long tail with lots of keys hardly ever used.

Over this logged time, I have registered key strokes during 46% of all hours. Counting only the hours in which I actually used the keyboard, the average number of key strokes were 2185/hour, 36 keys/minute.

The average week day (excluding weekend days), I registered 32486 key presses. The most active sinngle minute during this logging period, I hit 405 keys. The most active single hour I managed to do 7937 key presses. During weekends my activity is much lower, and then I average at 5778 keys/day (7.2% of all activity were weekends).

When counting most active hours over the day, there are 14 hours that have more than 1% activity and there are 5 with less than 1%, leaving 5 hours with no keyboard activity at all (02:00- 06:59). Interestingly, the hour between 23-24 at night is the single most busy hour for me, with 12.5% of all keypresses during the period.

Random “anecdotes”

Longest contiguous time without keys: 26.4 hours

Longest key sequence without backspace: 946

There are 7 keys I only pressed once during this period; 4 of them are on the numerical keypad and the other three are F10, F3 and <Pause>.

More

I’ll try to keep the logging going and see if things change over time or if there later might end up things that can be seen in the data when looked over a longer period.