An updated which package that fixes one bug is now available for Red Hat Enterprise Linux 6.
The "which" package includes the "which" command that shows the full pathname of a specified program, if the specified program is in your PATH.
Prior to this update, the /etc/profile.d/which2.csh file caused an alias for the "which" command to be created. As a result, the "which" command included in the "which" package was used instead of the built-in "which" command as included in the C shell (csh). The problem has been fixed in this update by removing the /etc/profile.d/which2.csh file so that the "which" command included in csh is now used as expected.
All users of "which" should upgrade to this updated package, which fixes this bug.