jehanne/sys/src/lib/ndb/ndblookval.c

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/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
#include <u.h>
#include <lib9.h>
#include <bio.h>
#include <ip.h>
#include <ndb.h>
/*
* Look for a pair with the given attribute. look first on the same line,
* then in the whole entry.
*/
Ndbtuple*
ndbfindattr(Ndbtuple *entry, Ndbtuple *line, char *attr)
{
Ndbtuple *nt;
/* first look on same line (closer binding) */
for(nt = line; nt;){
if(strcmp(attr, nt->attr) == 0)
return nt;
nt = nt->line;
if(nt == line)
break;
}
/* search whole tuple */
for(nt = entry; nt; nt = nt->entry)
if(strcmp(attr, nt->attr) == 0)
return nt;
return nil;
}
Ndbtuple*
ndblookval(Ndbtuple *entry, Ndbtuple *line, char *attr, char *to)
{
Ndbtuple *t;
t = ndbfindattr(entry, line, attr);
if(t != nil){
strncpy(to, t->val, Ndbvlen-1);
to[Ndbvlen-1] = 0;
}
return t;
}