ugh.book

166 csh, pipes, and find

po>

Hey, now the files are there! Just have to remember to cd to random

directories in order to get find to find things in them. What a crock of

Unix.

Poor Halstead must have the entry for his home directory in /etc/passwd

pointing off to some symlink that points to his real directory, so some com-

mands work for him and some don’t.

Why not modify find to make it follow symlinks? Because then any sym-

link that pointed to a directory higher up the tree would throw find into an

endless loop. It would take careful forethought and real programming to

design a system that didn’t scan endlessly over the same directory time

after time. The simple, Unix, copout solution is just not to follow symlinks,

and force the users to deal with the result.

As networked systems become more and more complicated, these prob-

lems are becoming harder and harder:

Date: Wed, 2 Jan 1991 16:14:27 PST

From: Ken Harrenstien <[email protected]>

Subject: Why find doesn’t find anything

To: UNIX-HATERS

I just figured out why the “find” program isn’t working for me any-

more.

Even though the syntax is rather clumsy and gross, I have relied on it

for a long time to avoid spending hours fruitlessly wandering up and

down byzantine directory hierarchies in search of the source for a

program that I know exists somewhere (a different place on each

machine, of course).

It turns out that in this brave new world of NFS and symbolic links,

“find” is becoming worthless. The so-called file system we have here

is a grand spaghetti pile combining several different fileservers with

lots and lots of symbolic links hither and thither, none of which the

program bothers to follow up on. There isn’t even a switch to request

this... the net effect is that enormous chunks of the search space are

silently excluded. I finally realized this when my request to search a

fairly sizeable directory turned up nothing (not entirely surprising,

but it did nothing too fast) and investigation finally revealed that the

directory was a symbolic link to some other place.