From: Peter Stephenson <p.w.stephenson@ntlworld.com>
To: zsh-workers@sunsite.dk (Zsh hackers list)
Subject: Re: PATCH: test of improved backslash quoting
Date: Thu, 23 Aug 2007 22:59:31 +0100 [thread overview]
Message-ID: <20070823225931.4da52ab7.p.w.stephenson@ntlworld.com> (raw)
In-Reply-To: <200708221035.l7MAZrrC009415@news01.csr.com>
On Wed, 22 Aug 2007 11:35:53 +0100
Peter Stephenson <pws@csr.com> wrote:
> Note that removal of $'...' quotes is not currently well handled: this
> applies both to the (Q) parameter flag and to completion, where already
> added $'\...' quoting isn't properly parsed for further handling.
I was right about that.
> This is part of the hairy patch I've been trying to do to improve
> completion with nested quotes; however, the (Q) part is useful
> separately and a bit more tractable, so I'll try and drag it out since
> it's likely to be several orders of magnitude quicker than trying to
> complete the full patch.
I was wrong about that. It's yet another separate special case.
However, it's not too hard to do with one caveat: it assumes the result
of $'...' is shorter than the original. That's usually the case, but
I'm worried there are pathological cases with metafied multibyte
strings. If someone wants to fix parse_subst_string() or prove it's OK
as it is that would be splendid. The difficulty with fixing
parse_subst_string() is that currently it acts in place and so no memory
management is necessary. It would need some fiddling to allocate a new
string from the right memory and avoid leaks.
Index: Src/lex.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/lex.c,v
retrieving revision 1.40
diff -u -r1.40 lex.c
--- Src/lex.c 14 Aug 2007 11:51:18 -0000 1.40
+++ Src/lex.c 23 Aug 2007 21:53:04 -0000
@@ -1556,6 +1556,7 @@
parse_subst_string(char *s)
{
int c, l = strlen(s), err, olen, lexstop_ret;
+ char *ptr;
if (!*s || !strcmp(s, nulstring))
return 0;
@@ -1593,6 +1594,43 @@
return 1;
}
#endif
+ /* Check for $'...' quoting. This needs special handling. */
+ for (ptr = s; *ptr; )
+ {
+ if (*ptr == String && ptr[1] == Snull)
+ {
+ char *t;
+ int len, tlen, diff;
+ t = getkeystring(ptr + 2, &len, GETKEYS_DOLLARS_QUOTE, NULL);
+ len += 2;
+ tlen = strlen(t);
+ diff = len - tlen;
+ /*
+ * Yuk.
+ * parse_subst_string() currently handles strings in-place.
+ * That's not so easy to fix without knowing whether
+ * additional memory should come off the heap or
+ * otherwise. So we cheat by copying the unquoted string
+ * into place, unless it's too long. That's not the
+ * normal case, but I'm worried there are are pathological
+ * cases with converting metafied multibyte strings.
+ * If someone can prove there aren't I will be very happy.
+ */
+ if (diff < 0) {
+ DPUTS(1, "$'...' subst too long: fix get_parse_string()");
+ return 1;
+ }
+ memcpy(ptr, t, tlen);
+ ptr += tlen;
+ if (diff > 0) {
+ char *dptr = ptr;
+ char *sptr = ptr + diff;
+ while ((*dptr++ = *sptr++))
+ ;
+ }
+ } else
+ ptr++;
+ }
return 0;
}
Index: Test/D04parameter.ztst
===================================================================
RCS file: /cvsroot/zsh/zsh/Test/D04parameter.ztst,v
retrieving revision 1.27
diff -u -r1.27 D04parameter.ztst
--- Test/D04parameter.ztst 25 Jul 2007 09:26:52 -0000 1.27
+++ Test/D04parameter.ztst 23 Aug 2007 21:53:04 -0000
@@ -320,6 +320,11 @@
0:${(Q)...}
>and now even the pubs are shut.
+ foo="X$'\x41'$'\x42'Y"
+ print -r ${(Q)foo}
+0:${(Q)...} with handling of $'...'
+>XABY
+
psvar=(dog)
setopt promptsubst
foo='It shouldn'\''t $(happen) to a %1v.'
--
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/
prev parent reply other threads:[~2007-08-23 22:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-22 10:35 Peter Stephenson
2007-08-23 21:59 ` Peter Stephenson [this message]
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