/usr/bin/which is a csh script. Start with a root login which uses the requisite POSIX shell and try this:
# type which
(type is an alias for whence -v, a much more useful command than which or whereis)
If: type which produces: "which is /usr/bin/which"
then try this:
# /usr/bin/which lp
If that works OK, then the previous command probably did not return: /usr/bin/which
The point is that the shell NOT run the command you expect unless $PATH and aliases are standard. type (and whence) will tell you exactly what the shell will run, something that which and whereis will not. Try:
# whereis history
# which history
# whence -v history
Once you know that /usr/bin/which is the command that is being run, the next is to see if something in the environment is overriding the shell interpreter line:
#! /usr/bin/csh
If this line is missing, then the current shell will be used to interpret the script. Thus, if you are running POSIX shell or ksh and the interpreter line is missing, you'll get the error listed in your subject line.
Perhaps someone has replaced /usr/bin/csh with /usr/bin/sh or /usr/bin/ksh? (some sysadmins would say this would be an improvement--I would never say that..)
Bill Hassell, sysadmin
