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#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
#include <ndbhf.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 0 if not found.
*/
char*
csgetvalue(char *netroot, char *attr, char *val, char *rattr, Ndbtuple **pp)
{
Ndbtuple *t, *first, *last;
int n, linefound;
char line[1024];
int fd;
int oops = 0;
char *rv;
if(pp)
*pp = nil;
rv = nil;
if(netroot)
snprint(line, sizeof(line), "%s/cs", netroot);
else
strcpy(line, "/net/cs");
fd = open(line, ORDWR);
if(fd < 0)
return 0;
seek(fd, 0, 0);
snprint(line, sizeof(line), "!%s=%s %s=*", attr, val, rattr);
if(write(fd, line, strlen(line)) < 0){
close(fd);
return 0;
}
seek(fd, 0, 0);
first = last = 0;
linefound = 0;
for(;;){
n = read(fd, line, sizeof(line)-2);
if(n <= 0)
break;
line[n] = '\n';
line[n+1] = 0;
t = _ndbparseline(line);
if(t == 0)
continue;
if(first)
last->entry = t;
else
first = t;
last = t;
while(last->entry)
last = last->entry;
for(; t; t = t->entry){
if(linefound == 0){
if(strcmp(rattr, t->attr) == 0){
linefound = 1;
rv = strdup(t->val);
}
}
}
}
close(fd);
if(oops){
werrstr("buffer too short");
ndbfree(first);
return nil;
}
if(pp){
setmalloctag(first, getcallerpc(&netroot));
*pp = first;
} else
ndbfree(first);
return rv;
}
Ndbtuple*
csgetval(char *netroot, char *attr, char *val, char *rattr, char *buf)
{
Ndbtuple *t;
char *p;
p = csgetvalue(netroot, attr, val, rattr, &t);
if(p == nil){
if(buf != nil)
*buf = 0;
} else {
if(buf != nil){
strncpy(buf, p, Ndbvlen-1);
buf[Ndbvlen-1] = 0;
}
free(p);
}
return t;
}
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