Archive for August, 2008

pscanf: a sscanf replacement for C

Wednesday, August 6th, 2008

In general, I like C. Pointers don’t generally bother me all that much, and its really nice to use for a lot of different things. However, its string handling SUCKS (though, printf is nice). It seems like a lot of the string routines in the standard C library are designed to screw you in the most unexpected ways possible.

So recently I’ve been struggling with processing input from a user on the command line, and I was using sscanf to attempt to do really simple string processing, and it simply wasn’t matching the correct things. After much struggling and coming to the realization that I needed to do something similar to regular expressions… I sat down and wrote the following function, and it works quite well for what I want to do.

What it does do:

  • Match arbitrary strings using a perl regex, and return the matches to you

What it doesn’t do:

  • This is not a drop-in replacement for sscanf: you need to change the format string around and (possibly) your parameters.
  • It will not return anything but a string. Thats all you get. Of course, if you format your regex correctly then you can pretty much be guaranteed that strtol/strtod/etc will work…
  • Give you any kind of comprehensive error reporting. If you want that, then just use the pcre functions directly
  • Cook your meals or do your laundry

This is released under the license contained on, enjoy!