OK, how do I count files in a directory QUICK!!!

[Matt Graham]

From: "kitepilot at kitepilot.com" <kitepilot at kitepilot.com>
> I'll keep it easy: It is a directory that only contains files.
> So, you'd say: what's wrong with "ls|wc -l" ? 
> There are almost a million files in that directory.
> This count has to be placed in a loop in a shell script to report a 
> second-to-second delta.

The directory organization is complete pants if there are that many files in
one dir.  Time to split some things up, eh?
 
> The truth is that find takes some 3 seconds to do the count.
> What about ls without sorting? That was almost 15 seconds. 

That's a bit strange.  I'd think "ls -1U --color=never" would spit everything
out almost as fast as possible, considering.

> Now, directories are files. It would be great if I could "count
> lines" on that [directory] or somehow interrogate it "how many
> lines do you have?" without actually hitting the filesystem.
> I'm considering writing a little C utility to do just that, but...
> "struct stat" (my first shot) doesn't contain that

#include<dirent.h>
#include<stdio.h>

int main(int argc, char **argv)
{

DIR *dirp;
struct dirent *entry;
int count=0;

if(argc != 2){
   printf("usage: checkdir <directory to check>\n");
   exit(1);
   }

dirp=opendir(argv[1]);
if(dirp==NULL){
   printf("couldn't open %s\n",argv[1]);
   exit(1);
   }
while((entry=readdir(dirp))!=NULL){
   count++;
   }
printf("%d files in %s\n",count,argv[1]);
exit(0);

}

...this counts all files; all dirs have at least 2 entries in them, . and .. ,
so subtract 2 or do count-=2 or whatever.  Note that this does no filetype
checking at all and checking of errors is minimal.  I can't see how to do what
you want any faster without going below glibc, which is pretty hairy.

Also, see if you can rearrange the dir structure.  Having a million files in
one dir can cause silliness.  HTH,


-- 
Matt G / Dances With Crows
The Crow202 Blog:  http://crow202.org/wordpress/
There is no Darkness in Eternity/But only Light too dim for us to see