72 lines
1.2 KiB
C
72 lines
1.2 KiB
C
#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;
|
|
char line[1024];
|
|
int fd, n;
|
|
char *rv;
|
|
|
|
if(pp != nil)
|
|
*pp = nil;
|
|
|
|
if(netroot)
|
|
snprint(line, sizeof(line), "%s/cs", netroot);
|
|
else
|
|
strcpy(line, "/net/cs");
|
|
fd = open(line, ORDWR|OCEXEC);
|
|
if(fd < 0)
|
|
return nil;
|
|
|
|
snprint(line, sizeof(line), "!%s=%s %s=*", attr, val, rattr);
|
|
if(write(fd, line, strlen(line)) < 0){
|
|
close(fd);
|
|
return nil;
|
|
}
|
|
seek(fd, 0, 0);
|
|
|
|
rv = nil;
|
|
first = last = nil;
|
|
for(;;){
|
|
n = read(fd, line, sizeof(line)-2);
|
|
if(n <= 0)
|
|
break;
|
|
line[n] = '\n';
|
|
line[n+1] = 0;
|
|
|
|
t = _ndbparseline(line);
|
|
if(t == nil)
|
|
continue;
|
|
if(first != nil)
|
|
last->entry = t;
|
|
else
|
|
first = t;
|
|
do {
|
|
last = t;
|
|
if(rv == nil && strcmp(rattr, t->attr) == 0)
|
|
rv = strdup(t->val);
|
|
t = t->entry;
|
|
} while(t != nil);
|
|
}
|
|
close(fd);
|
|
|
|
if(pp != nil){
|
|
setmalloctag(first, getcallerpc(&netroot));
|
|
*pp = first;
|
|
} else
|
|
ndbfree(first);
|
|
|
|
return rv;
|
|
}
|