[Bug 251770] /bin/sh: false expansion

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=251770

--- Comment #4 from Steffen (Daode) Nurpmeso <steffen at sdaoden.eu> ---
Sorry for being so late, i wanted to reread the standard text, maybe to open an
issue.  But i think your last statement pretty much describes the situation. 
(Whereas my initial report was only "from gut".)

3385   4.23        Variable Assignment
3386               In the shell command language, a word consisting of the
following parts:
3387               varname=value
3388               When used in a context where assignment is defined to occur
and at no other time, the value
3389               (representing a word or field) shall be assigned as the
value of the variable denoted by varname.
3390               Note:          For further information, see XCU Section
2.9.1 (on page 2365).

---

75482   2.9.1        Simple Command

75495                    4.    Each variable assignment shall be expanded for
tilde expansion, parameter expansion,
75496                          command substitution, arithmetic expansion, and
quote removal prior to assigning the
75497                          value.

---

75501          Variable assignments shall be performed as follows:
75502             •   If no command name results, variable assignments shall
affect the current execution
75503                 environment.

---

So everything should be handled sequentially, making it a bug.

---

75504             •   If the command name is not a special built-in utility or
function, the variable assignments
[.]
75507                 4. In this case it is unspecified:
75508                   — Whether or not the assignments are visible for
subsequent expansions in step 4
75509                   — Whether variable assignments made as side-effects of
these expansions are visible for
75510                     subsequent expansions in step 4, or in the current
shell execution environment, or
75511                     both

---

So it allows to setup the "execution environment of the command" entirely from
the current environment, which is effectively read-only.  As you say.

-- 
You are receiving this mail because:
You are the assignee for the bug.