cudcv@daisy.warwick.ac.uk (Rob McMahon) (03/14/88)
<munch>
One of our students reported the following bug to me:
% if ( abc =~ * ) echo yes
<silence>
% if ( abc =~ ** ) echo yes
yes
Further investigation gave the following:
% if ( 0 =~ * ) echo yes
yes
% if ( 2 == 2 + ) echo yes
yes
% if ( 2 == + 2 ) echo yes
yes
The * is being treated as multiply, and the shell doesn't care that it's
got no operands, it just fills them in with 0. I've applied the
following fix, but I'm slightly unsure about it because I may have
broken something---that check for an operator and return("") looks very
deliberate, what did they have in mind ? In particular "if ( x == - y )"
now breaks, it has to be "if ( x == 0 - y )", but then it seems these
only worked by accident anyway, and surely "if ( x = * y )" should be a
syntax error ? Any comments ?
Here's the fix:
RCS file: sh.exp.c,v
retrieving revision 1.1
diff -c -r1.1 sh.exp.c
*** /tmp/,RCSt1a05867 Sun Mar 13 19:06:09 1988
--- sh.exp.c Sun Mar 13 18:50:36 1988
***************
*** 419,426 ****
#endif
return (putn(egetn(value("status")) == 0));
}
if (isa(**vp, ANYOP))
! return ("");
cp = *(*vp)++;
if (*cp == '-' && any(cp[1], "erwxfdzo")) {
struct stat stb;
--- 419,436 ----
#endif
return (putn(egetn(value("status")) == 0));
}
+ /*
+ * if we're looking for a pattern the globbing chars count as strings,
+ * not operators.
+ */
+ if ((ignore&NOGLOB) && (***vp == '[' || ***vp == '*'))
+ return (savestr(*(*vp)++));
+ /*
+ * if we've got an operator now, then we haven't got an operand
+ * for it.
+ */
if (isa(**vp, ANYOP))
! bferr("Expression syntax");
cp = *(*vp)++;
if (*cp == '-' && any(cp[1], "erwxfdzo")) {
struct stat stb;
--
UUCP: ...!mcvax!ukc!warwick!cudcv PHONE: +44 203 523037
JANET: cudcv@uk.ac.warwick.cu ARPA: cudcv@cu.warwick.ac.uk
Rob McMahon, Computing Services, Warwick University, Coventry CV4 7AL, Englandgreim@sbsvax.UUCP (Michael Greim) (04/14/88)
Hello, I just had the time to look into it. I must admit that Rob McMahon's fixed fix is really better than mine. So just re-read the prior messages on this subject: <479@sol.warwick.ac.uk> <469@sbsvax.UUCP> <512@sol.warwick.ac.uk> <478@sbsvax.UUCP> and apply the fix Rob proposed in <479@sol.warwick.ac.uk> together with the fix he mentioned in <512@sol.warwick.ac.uk>. And just forget my fix for this problem. I am sorry if I have caused any confusion. Michael PS: Rob, if I offended you in any way, please accept my appologies. -- +------------------------------------------------------------------------------+ | UUCP: ...!uunet!unido!sbsvax!greim | Michael T. Greim | | or greim@sbsvax.UUCP | Universitaet des Saarlandes | | CSNET: greim%sbsvax.uucp@Germany.CSnet| FB 10 - Informatik (Dept. of CS) | | ARPA: greim%sbsvax.uucp@uunet.UU.NET | Bau 36, Im Stadtwald 15 | | Phone: +49 681 302 2434 | D-6600 Saarbruecken 11, West Germany | +------------------------------------------------------------------------------+ | Watch this space. Don't let it escape. | +------------------------------------------------------------------------------+