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Re: Problems with the functions[] parameter (not; but other issues)



On Mar 10,  1:45pm, Sven Wischnowsky wrote:
} Subject: Re: Problems with the functions[] parameter (not; but other issue
}
} Bart Schaefer wrote:
} > (2) Redirecting stderr of a function is a bit inconsistent with respect
} >     to xtrace.  Zsh presently works the same way bash does, which means
} >     the xtrace output of shell functions is *not* redirected along with
} >     their stderr.  This is not the same as e.g. `do'-loops and { ... }.
} 
} What really irritated me here (and it still looks wrong): add
} 
}   set -x
}   _call version diff -v </dev/null 2>/dev/null
}   set +x
} 
} Only the `first' line of _call is shown, xtrace output stops when
} zstyle is called.

Yes, I saw that too.  Improper restoration of xtrerr.  Patch below.

} Or maybe my exec.c is out-of date, because:
} 
} > And (2) in turn leads me to notice a third thing:
} > 
} > In bash, redirecting the standard error of the `.' command redirects
} > the xtrace output from the commands in the sourced file.  This doesn't
} > presently happen in zsh, but I think the zsh behavior is more useful;
} > other opinions?  Is compatibility more important?  What does ksh do?
} 
} if I do `. ./foo 2> bar' I get the xtrace output of the commands in
} `foo' in `bar'. Same as for the ksh I have here, btw.

The patch below may change this -- the behavior I previously saw for `.'
was the same as what you described for `_call' -- that is, the first line
of ./foo would xtrace to the (old) stderr, and then everything else would
be redirected to `bar', because xtrerr was getting reset too soon.

The patch below leaves `.' behaving like functions do.  If we want `.'
(and `source') to act like a shell construct instead (for bash and ksh
compatibility if nothing else) then we'll have to set xtrerr back to
stderr (temporarily) in either builtin.c:bin_dot() or init.c:source().

Index: Src/exec.c
===================================================================
@@ -1608,6 +1608,7 @@
     LinkList redir;
     wordcode code;
     Wordcode beg = state->pc, varspc;
+    FILE *oxtrerr = xtrerr;
 
     doneps4 = 0;
     redir = (wc_code(*state->pc) == WC_REDIR ? ecgetredirs(state) : NULL);
@@ -2317,10 +2318,10 @@
     fixfds(save);
 
  done:
-    if (xtrerr != stderr) {
+    if (xtrerr != oxtrerr) {
 	fil = fileno(xtrerr);
 	fclose(xtrerr);
-	xtrerr = stderr;
+	xtrerr = oxtrerr;
 	zclose(fil);
     }
 }

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com



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