What puzzles me is, that I am getting different output running this two-liner script:
help | head -n1
type mkdir
from within SciTE (here the SciTE output panel output):
GNU bash, version 4.3.46(1)-release (x86_64-pc-linux-gnu)
mkdir is /bin/mkdir
and from within a Terminal window (here the Terminal output):
GNU bash, version 4.3.46(1)-release (x86_64-pc-linux-gnu)
mkdir is hashed (/bin/mkdir)
How does it come that the same script executed by the same shell gives not the same output?
The difference is situational:
The first time bash executes an external utility in a given session by filename only (whether successfully or not), it remembers its full path for faster re-execution later (saving the need to look for the utility in all directories listed in the $PATH variable again).
This remembering (caching) is called hashing and happens implicitly via builtin hash.
Therefore, before mkdir is ever executed in a given session, type mkdir returns:
mkdir is /bin/mkdir
After having executed mkdir at least once, type mkdir then reports:
mkdir is hashed (/bin/mkdir)
You can tell bash to "forget" all remembered paths with hash -r, or selectively with hash -d <name>; just hash prints all currently hashed paths and their hit counts - see help hash.