Why are Mac command line utilities running so slowly?

I have just noticed that command line utilities such as ls, touch, cat, etc. are very slow when I run them from Terminal or iTerm on my MacBook. For example:

• ls'ing while in an empty directory takes 1 second (it also takes 1 second in a non-empty directory, both with lots of files or with a few files);


• touch'ing a new file takes 1 second (it also takes 1 second to touch an existing file);


• cat'ing an empty file takes 1 second (there is also a 1 second lag before anything happens when I cat a non-empty file).

I have tried to diagnose this in many ways but to no avail. I do not think this is a filesystem issue, since:

• 
  

  I have run Disk Utility and it reports no problems.

  
  


• 
  

  Everything seems to be working just fine in Finder, e.g. directory contents are shown instantaneously in Finder.

  
  


• 
  

  I installed GNU coreutils and tried using gls, gtouch, gcat, etc., and all of the operations I listed above happen instantaneously when run with the GNU version instead.

  
  

Any ideas on how to fix this?