Subject: Re: Re: [shell-discuss] More ksh93 builtins [PSARC/2010/095 FastTrack
timeout 03/25/2010]
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Let me clear up some misunderstands about ksh93 built-ins.
There are a few types of built-ins in ksh93.
1. There are special built-ins (example break, continue, return, set,
typeset, trap (and many others) as described by the standard.
2. built-ins that behave like commands but are always built-in such
as pwd and echo.
3. Built-ins that are bound to a path, for example /bin/date. A built-in
that is bound to a path is only executed when a PATH search finds the
command in the directory. You would only bind a built-in to a path
if it is compatible. (Since the shell uses device-inode to detect
equivalent paths, if /bin and /usr/bin are the same, a built-in of
/bin/date will also find /usr/bin/date).
I beleive that the case that is proposed, adds these built-ins as built-ins
bound to a path.
Thus, if someone wants to use the gnu version, they could put
/usr/gnu/bin before /bin, you will get the gnu binary and suffer the
performance hit.
David Korn
dgk at research.att.com
