Re: Bug Report: Env Vars and shell functions

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

On Jul 12,  5:27pm, Zoltan Hidvegi wrote:
} Subject: Re: Bug Report: Env Vars and shell functions
}
} > On a related note, should the following not restore IFS?
} > 
} > sun4% IFS=@ set a@b@c@d; echo $IFS 
} > @
} 
} Here is what POSIX says:
} 
}      (2)  Variable assignments specified with special built-in utilities
}           shall remain in effect after the built-in completes; this shall
}           not be the case with a regular built-in or other utility.
} 
} And it also says that shell functions should be handled similarily to
} special builtins (which means that recent patches from Peter and me make
} zsh less conformant).

But more intuitive.  I suspect POSIX was merely codifying existing sh/ksh
behavior there.

} Zsh currently treats a builtin this way

Clarity:  Zsh treats a builtin the way it treats a shell function ...

} only if the BINF_MAGICEQUALS flag
} is set for the builtin.  These builtins are: alias, declare, hash, integer,
} local, readonly and typeset.

[...]

} Of course zsh does not conforms to the POSIX rule and handling of special
} parameters in undoubtadly not the best but it also means that applications
} should not expect local variable assignments before special builtins since
} it may change in the future.

Hopefully it would merely become dependent on a POSIX-compliance option;
the whole reason for introducing the BINF_MAGICEQUALS behavior was so
that applications could expect these local variable assignments.

} Also note that command arguments are evaluated before variable assignments
} so the above example will never work.

Has this always been the case?  (Peter?)  Is this correct according to
POSIX?  Of what use is the BINF_MAGICEQUALS behavior if the args are
evaluated before the variable gets assigned?

} In a POSIX shell the command builtin can be used to execute special
} builtins (in zsh it executes external command only).  Note that command in
} not listed among the special builtins above which means that the special
} assignment behaviour can be prevented by prefixing a special builtin with
} the command builtin (I'm talking about POSIX and not about zsh).

Hmm.  So `command typeset foo=bar ; echo $foo' has what effect in POSIX?

} I'm writing these because these differences between zsh and POSIX are
} probably the most important ones.

Perhaps that means they should be recorded somewhere, maybe Etc/BUGS or
a new file?  (Where's the wish-list/ToDo-list nowadays?)

-- 
Bart Schaefer                             Brass Lantern Enterprises
http://www.well.com/user/barts            http://www.nbn.com/people/lantern

New male in /home/schaefer:
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