On 2/18/18 11:50 PM, Harald van Dijk wrote:
On 2/14/18 11:50 PM, Harald van Dijk wrote:
On 2/14/18 10:44 PM, Harald van Dijk wrote:
On 2/14/18 9:03 PM, Harald van Dijk wrote:
On 13/02/2018 14:53, Denys Vlasenko wrote:
$ >'\zzzz'
$ >'\wwww'
$ dash -c 'echo "\*"'
\wwww \zzzz
[...]
Currently:
$ dash -c 'foo=a; echo "<${foo#[a\]]}>"'
<>
This is what I expect, and also what bash, ksh and posh do.
With your patch:
$ dash -c 'foo=a; echo "<${foo#[a\]]}>"'
<a>
Does the attached look right as an alternative? It treats a quoted
backslash the same way as if it were preceded by CTLESC in
_rmescapes. It passes your test case and mine, but I'll do more
extensive testing.
It causes preglob's string to potentially grow larger than the
original. When called with RMESCAPE_ALLOC, that can be handled by
increasing the buffer size, but preglob also gets called without
RMESCAPE_ALLOC to modify a string in-place. That's never going to work
with this approach. Back to the drawing board...
There is a way to make it work: ensure sufficient memory is always
available. Instead of inserting CTLESC, which caused problems,
CTLQUOTEMARK+CTLQUOTEMARK can be inserted instead. It's effectively a
no-op here.
It required one obvious additional trivial change to the CHECKSTRSPACE
invocation, but with that added, the attached passed all testing I could
think of. Does this look okay to include, did I miss something, or is
there perhaps a better alternative?
Cheers,
Harald van Dijk
diff --git a/src/expand.c b/src/expand.c
index 2a50830..af88a69 100644
--- a/src/expand.c
+++ b/src/expand.c
@@ -1686,12 +1686,17 @@ _rmescapes(char *str, int flag)
}
if (*p == (char)CTLESC) {
p++;
- if (notescaped)
- *q++ = '\\';
- } else if (*p == '\\' && !inquotes) {
- /* naked back slash */
- notescaped = 0;
- goto copy;
+ goto escape;
+ } else if (*p == '\\') {
+ if (inquotes) {
+escape:
+ if (notescaped)
+ *q++ = '\\';
+ } else {
+ /* naked back slash */
+ notescaped = 0;
+ goto copy;
+ }
}
notescaped = globbing;
copy:
diff --git a/src/parser.c b/src/parser.c
index 382658e..a847b2e 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -909,7 +909,7 @@ readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
#endif
CHECKEND(); /* set c to PEOF if at end of here document */
for (;;) { /* until end of line or end of word */
- CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */
+ CHECKSTRSPACE(5, out); /* permit 5 calls to USTPUTC */
switch(syntax[c]) {
case CNL: /* '\n' */
if (syntax == BASESYNTAX)
@@ -944,6 +944,9 @@ readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
eofmark != NULL
)
) {
+ /* Reserve extra memory in case this backslash will require later escaping. */
+ USTPUTC(CTLQUOTEMARK, out);
+ USTPUTC(CTLQUOTEMARK, out);
USTPUTC('\\', out);
}
USTPUTC(CTLESC, out);
