On Fri Oct 23 22:47:46 EDT 2009, [email protected] wrote:
> try using [_a-zA-Z][_a-zA-Z0-9] rather than the expanded form. i
> didn't track it down to be sure, but plan 9 awk seem to have a limit
> 34 characters inside square brackets. a rather odd number
>
> cpu% echo hello | awk '/^[abcdefghijklmnopqrstuvwxyzABCDEFGH].+/ {
> line = $0 ; print line }'
> cpu% echo hello | awk '/^[abcdefghijklmnopqrstuvwxyzABCDEFG].+/ { line
> = $0 ; print line }'
> hello
there are two bits to fixing this. steve simon
submitted an excellent patch, which i applied.
but i think there is still a bug. 34 is as noted a
really wierd number.
a bit of background: the way cclasses work is
that each entry gets 2 entries. a start and
an end. for a-b the start is a and the end is b.
for just a, the start and end are both a. one
would expect since the original code has 64
spaces, we would get a maximum of 32 chars
per class. however, /sys/src/ape/lib/regexp/regcomp.h
has
/* max rune ranges per character class */
#define NCCRUNE (sizeof(Reclass)/sizeof(wchar_t))
which is wrong since there is more stuff in Reclass
than an array of wchar_t's. this is a big problem
since it will scribble 4 bytes past the end of the
Reclass.
these are the diffs i came up with. they attack
the problem a bit differently, but i think it's a
bit cleaner and worth a few extra lines of diff:
; 9diff regcomp.h
/n/sources/plan9//sys/src/ape/lib/regexp/regcomp.h:1,23 - regcomp.h:1,17
/*
* substitution list
*/
+ enum {
+ NSUBEXP = 32,
+ LISTINCREMENT = 8,
+ };
+
typedef struct Resublist Resublist;
struct Resublist
{
- Resub m[32];
+ Resub m[NSUBEXP];
};
- /* max subexpressions per program */
- Resublist ReSuBlIsT;
- #define NSUBEXP (sizeof(ReSuBlIsT.m)/sizeof(Resub))
-
- /* max character classes per program */
- Reprog RePrOg;
- #define NCLASS (sizeof(RePrOg.class)/sizeof(Reclass))
-
- /* max rune ranges per character class */
- #define NCCRUNE (sizeof(Reclass)/sizeof(wchar_t))
-
/*
* Actions and Tokens (Reinst types)
*
/n/sources/plan9//sys/src/ape/lib/regexp/regcomp.h:46,52 - regcomp.h:40,45
/*
* regexec execution lists
*/
- #define LISTINCREMENT 8
typedef struct Relist Relist;
struct Relist
{
; 9diff regexp.h
/n/sources/plan9//sys/include/ape/regexp.h:35,43 - regexp.h:35,50
/*
* character class, each pair of rune's defines a range
*/
+ enum{
+ NCCRUNE = 256,
+ NCLASS = 16,
+ NINST = 5,
+
+ };
+
struct Reclass{
wchar_t *end;
- wchar_t spans[64];
+ wchar_t spans[NCCRUNE];
};
/*
/n/sources/plan9//sys/include/ape/regexp.h:62,69 - regexp.h:69,76
*/
struct Reprog{
Reinst *startinst; /* start pc */
- Reclass class[16]; /* .data */
- Reinst firstinst[5]; /* .text */
+ Reclass class[NCLASS]; /* .data */
+ Reinst firstinst[NINST]; /* .text */
};
extern Reprog *regcomp(char*);
- erik
