Re: bug, i think? pwd --help and pwd --version don't work

[Eric Blake]

> address@hidden ~]$ pwd --help
> bash: pwd: --: invalid option
> pwd: usage: pwd [-PL]
> 
> address@hidden ~]$ which pwd
> /usr/local/bin/pwd
> 
> Strange. Any idea what's going wrong? 

Yes - which(1) is not required by POSIX, but it is a tcsh builtin that 
corresponds to the POSIX-required type(1).  Depending on whether type/which is 
a program, an alias, or a shell-builtin, it reports different information - 
only a shell builtin can report correct information about shell builtins and 
aliases.  In conclusion, your information about what pwd really is depends on 
how you ask.  On my system:

$ bash    # where pwd is builtin, type is builtin, which is program
$ type pwd
pwd is a shell builtin
$ which pwd
/usr/bin/pwd
$ type which
which is hashed (/usr/bin/which)
$ which which
/usr/bin/which
$ type type
type is a shell builtin
$ which type
type: Command not found.

$ tcsh     # where pwd is program, type is alias for which, which is builtin
# type pwd
/usr/bin/pwd
# \type pwd
type: Command not found.
# which pwd
/usr/bin/pwd
# type which
which: shell built-in command.
# which type
type:    aliased to which
#

If you want the tcsh behavior of which inside of bash, then do something like 
one of these two options:
$ alias which type
$ which()
{
  type "$@"
}

--
Eric Blake