What can you do in 2k LOC of C?

#1

Post by s3graham » Thu, Feb 03, 2011, 9:36 PM UTC

What can you do in 2k LOC of C?
h4ck3r.net

Re: What can you do in 2k LOC of C?

#2

Post by mayank » Thu, Feb 03, 2011, 10:40 PM UTC

I wrote EasyEXIF: http://code.google.com/p/easyexif/

About 120 lines of C++ [see 1] that parses basic EXIF information out of a JPEG image. I found all the other EXIF parsing tools and libraries a little too heavyweight for something as simple as getting the date and time a picture was taken, or the f/stop or exposure time. It only uses string.h for memcpy and memset, and no other headers.

[1] http://code.google.com/p/easyexif/source/browse/trunk/exif.c... (note: Google's source view screws up my whitespace)

Re: What can you do in 2k LOC of C?

#3

Post by silentbicycle » Thu, Feb 03, 2011, 11:08 PM UTC

I'm working on a text indexing/retrieval program, like locate (http://www.openbsd.org/cgi-bin/man.cgi?query=locate) but for content and not just filenames, and with an index It's very nearly together (integrating individually working parts now), and is currently ~1,500 lines (according to sloccount).

Adding support for indexing Unicode text, more configuration, composite search queries (A and B near C and not D), etc. will no doubt make the source expand a bit, but it's still pretty small.

If you're interested in trying it out once it's ready, contact info is in my profile. I'm shooting for within a week or two for a beta vulgaris. (Requires Unix. ANSI C, strung together with sh and/or awk to avoid dependencies.)

Re: What can you do in 2k LOC of C?

#4

Post by whakojacko » Thu, Feb 03, 2011, 11:16 PM UTC

Anyone know how big nginx is? I wouldnt at all be surprised if its under 2k LOC.

Re: What can you do in 2k LOC of C?

#5

Post by maximilianburke » Thu, Feb 03, 2011, 11:22 PM UTC

whakojacko wrote: post #4

Anyone know how big nginx is? I wouldnt at all be surprised if its under 2k LOC.

As of 0.9.4, the core module is almost 21,000 lines of code and the entire nginx source tree is about 118,000 lines.

Re: What can you do in 2k LOC of C?

#6

Post by silentbicycle » Thu, Feb 03, 2011, 11:23 PM UTC

whakojacko wrote: post #4

Anyone know how big nginx is? I wouldnt at all be surprised if its under 2k LOC.

You're probably joking, but sloccount says:

    ansic:        82714 (99.68%)
    perl:           124 (0.15%)
    sh:              78 (0.09%)
    asm:             48 (0.06%)
    cpp:             17 (0.02%)

(for nginx-0.8.53)

Re: What can you do in 2k LOC of C?

#7

Post by abecedarius » Thu, Feb 03, 2011, 11:46 PM UTC

I was tempted to show off some toys I feel fatherly pride for, like my 500-line spreadsheet, but the only C program in this size range that I still use much is http://wry.me/~darius/software/req.tar.gz -- a rewrite-rule-based programmable calculator. Since it's >20 years old it's not at all what I'd write now.

(Toy spreadsheet at https://github.com/darius/vicissicalc)

Re: What can you do in 2k LOC of C?

#8

Post by sliverstorm » Thu, Feb 03, 2011, 11:50 PM UTC

If you think about it for a second, you realize that TrueType rasterization can't be that hard because printers were doing it long ago on crappy little embedded processors, but the default is just to fall back on the big ugly library, and then wrap it and pretend it's not there. How about instead, just write some good code?

This is why 'modern' software can still manage to bring a 3GHz quad-core to it's knees, IMHO

Re: What can you do in 2k LOC of C?

#9

Post by pygy_ » Thu, Feb 03, 2011, 11:52 PM UTC

Roberto Ierusalimschy's lpeg is around 2.4k loc of ansi C without any dependency beside libC and lua.h (needed to interface with Lua, since it's a Lua library).

It implements an efficient pattern matching system based on Parsing Expression Grammars (akin to CFGs, but without ambiguities). It consists of a Pattern/Grammar to bytecode compiler and a custom VM to interpret the result of the compiling phase.

Nice and clean.

http://www.inf.puc-rio.br/~roberto/lpeg/lpeg.html

http://en.wikipedia.org/wiki/Parsing_expression_grammar

Re: What can you do in 2k LOC of C?

#10

Post by sliverstorm » Thu, Feb 03, 2011, 11:54 PM UTC

sliverstorm wrote: post #8

If you think about it for a second, you realize that TrueType rasterization can't be that hard because printers were doing it long ago on crappy little embedded processors, but the default is just to fall back on the big ugly library, and then wrap it and pretend it's not there. How about instead, just write some good code? This is why 'modern' software can still manage to bring a 3GHz quad-core to it's knees, IMHO

I personally suspect the explosion of storage space is the biggest factor in all this. I was just writing software for a uC with 2kb program space last week, and I started to bump into the limit. Optimizing my code for size actually resulted in much better code, because I had to stop and think "How can I do this... smarter?"

(Though if you're trying to fit 8kb into 2kb and have to start doing voodoo, it's true the quality will suffer)