ref: a7081490dbeda19788e6374a080ee38606aa3cd3
dir: /sys/src/libndb/ndbgetval.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include "ndb.h"
/*
* search for a tuple that has the given 'attr=val' and also 'rattr=x'.
* copy 'x' into 'buf' and return the whole tuple.
*
* return nil if not found.
*/
char*
ndbgetvalue(Ndb *db, Ndbs *s, char *attr, char *val, char *rattr, Ndbtuple **pp)
{
Ndbtuple *t, *nt;
char *rv;
Ndbs temps;
if(s == nil)
s = &temps;
if(pp)
*pp = nil;
t = ndbsearch(db, s, attr, val);
while(t != nil){
nt = ndbfindattr(t, s->t, rattr);
if(nt != nil){
rv = strdup(nt->val);
if(pp != nil)
*pp = t;
else
ndbfree(t);
return rv;
}
ndbfree(t);
t = ndbsnext(s, attr, val);
}
return nil;
}