Michal Politowski <[EMAIL PROTECTED]> writes:
> On Sun, 5 Nov 2006 19:41:40 -0800, Russ Allbery wrote:
> [...]
>> + <item><tt>local</tt> to create a scoped variable must be
>> + supported</item>
> Underspecified. local in dash and bash behave differently. In dash the
> variable value from outer scope is retained, in bash it is not.
> Bugs caused by this do happen: see eg. #381237
> Also local in dash is documented to be only allowed at the beginning of
> a function, and take only variable names, not assignments, as arguments,
> though in practice it seems this is not enforced and more bash-like
> behaviour works.
Here's a revised patch. Does this resolve that concern?
--- orig/policy.sgml
+++ mod/policy.sgml
@@ -6727,33 +6727,45 @@
<p>
The standard shell interpreter <file>/bin/sh</file> can be a
- symbolic link to any POSIX compatible shell, if <tt>echo
- -n</tt> does not generate a newline.<footnote>
- Debian policy specifies POSIX behavior for
- <file>/bin/sh</file>, but <tt>echo -n</tt> has widespread
- use in the Linux community (in particular including this
- policy, the Linux kernel source, many Debian scripts,
- etc.). This <tt>echo -n</tt> mechanism is valid but not
- required under POSIX, hence this explicit addition.
- Also, rumour has it that this shall be mandated under
- the LSB anyway.
- </footnote>
+ symbolic link to any POSIX compatible shell provided that it
+ supports the following additional features not mandated by
+ POSIX:
+ <list>
+ <item><tt>echo -n</tt> must not generate a newline<footnote>
+ Debian policy specifies POSIX behavior for
+ <file>/bin/sh</file>, but <tt>echo -n</tt> has widespread
+ use in the Linux community (in particular including this
+ policy, the Linux kernel source, many Debian scripts,
+ etc.). This <tt>echo -n</tt> mechanism is valid but not
+ required under POSIX, hence this explicit addition. Also,
+ rumour has it that this shall be mandated under the LSB
+ anyway.
+ </footnote>
+ </item>
+ <item>the <tt>-a</tt> and <tt>-o</tt> <tt>test</tt> operators
+ must be supported</item>
+ <item><tt>local</tt> to create a scoped variable must be
+ supported; however, <tt>local</tt> may or may not preserve
+ the variable value from an outer scope and may or may not
+ support arguments more complex than simple variable
+ names</item>
+ </list>
Thus, shell scripts specifying <file>/bin/sh</file> as
- interpreter must only use POSIX features. If a script
- requires non-POSIX features from the shell interpreter, the
- appropriate shell must be specified in the first line of the
- script (e.g., <tt>#!/bin/bash</tt>) and the package must
- depend on the package providing the shell (unless the shell
- package is marked "Essential", as in the case of
- <prgn>bash</prgn>).
+ interpreter must only use POSIX features or features guaranteed
+ by the above list. If a script requires other non-POSIX features
+ from the shell interpreter, the appropriate shell must be
+ specified in the first line of the script (e.g.,
+ <tt>#!/bin/bash</tt>) and the package must depend on the package
+ providing the shell (unless the shell package is marked
+ "Essential", as in the case of <prgn>bash</prgn>).
</p>
<p>
- You may wish to restrict your script to POSIX features when
- possible so that it may use <file>/bin/sh</file> as its
- interpreter. If your script works with <prgn>dash</prgn>
- (originally called <prgn>ash</prgn>), it's probably POSIX
- compliant, but if you are in doubt, use
+ You may wish to restrict your script to POSIX features plus the
+ above set when possible so that it may use <file>/bin/sh</file>
+ as its interpreter. If your script works with <prgn>dash</prgn>
+ (originally called <prgn>ash</prgn>), it probably complies with
+ the above requirements, but if you are in doubt, use
<file>/bin/bash</file>.
</p>
--
Russ Allbery ([EMAIL PROTECTED]) <http://www.eyrie.org/~eagle/>
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