On Tue, 2010-06-01 at 10:42:35 -0700, Russ Allbery wrote: > Here is proposed wording, which hopefully reflects the subsequent > discussion. I'm looking for seconds. > > diff --git a/policy.sgml b/policy.sgml > index d16df70..1871d4c 100644 > --- a/policy.sgml > +++ b/policy.sgml > @@ -6011,7 +6011,7 @@ rmdir /usr/local/share/emacs 2>/dev/null || true > </p> > </sect1> > > - <sect1> > + <sect1 id="writing-init"> > <heading>Writing the scripts</heading> > > <p> > @@ -6062,6 +6062,23 @@ rmdir /usr/local/share/emacs 2>/dev/null || true > </p> > > <p> > + Be careful of using <tt>set -e</tt> in <file>init.d</file> > + scripts. Writing correct <file>init.d</file> scripts requires > + accepting various error exit statuses when daemons are already > + running or already stopped without aborting > + the <file>init.d</file> script, and common <file>init.d</file> > + function libraries are not safe to call with <tt>set -e</tt> > + in effect<footnote> > + <tt>/lib/lsb/init-functions</tt>, which assists in writing > + LSB-compliant init scripts, may fail if <tt>set -e</tt> is > + in effect and echoing status messages to the console fails, > + for example. > + </footnote>. For <tt>init.d</tt> scripts, it's often easier > + to not use <tt>set -e</tt> and instead check the result of > + each command separately. > + </p> > + > + <p> > If a service reloads its configuration automatically (as > in the case of <prgn>cron</prgn>, for example), the > <tt>reload</tt> option of the <file>init.d</file> script > @@ -7158,13 +7175,19 @@ strip --strip-unneeded <var>your-lib</var> > language currently used to implement it. > </p> > <p> > - Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>) > - should almost certainly start with <tt>set -e</tt> so that > - errors are detected. Every script should use > - <tt>set -e</tt> or check the exit status of <em>every</em> > - command. > + Shell scripts (<prgn>sh</prgn> and <prgn>bash</prgn>) other than > + <file>init.d</file> scripts should almost certainly start > + with <tt>set -e</tt> so that errors are detected. > + <file>init.d</file> scripts are something of a special case, due > + to how frequently they need to call commands that are allowed to > + fail, and it may instead be easier to check the exit status of > + commands directly. See <ref id="writing-init"> for more > + information about writing <file>init.d</file> scripts. > + </p> > + <p> > + Every script should use <tt>set -e</tt> or check the exit status > + of <em>every</em> command. > </p> > - > <p> > Scripts may assume that <file>/bin/sh</file> implements the > SUSv3 Shell Command Language<footnote> Seconded. regards, guillem
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