DOKK / manpages / debian 11 / libowfat-dev / cdb_find.3.en
cdb_find(3) Library Functions Manual cdb_find(3)

cdb_find - look up a key in a constant database

#include <cdb.h>
#include <uint32.h>

int cdb_find(struct cdb *c,char *key,unsigned long int keylen);
int cdb_datalen(struct cdb *c);
int cdb_datapos(struct cdb *c);
int cdb_findnext(struct cdb *c,char *key,unsigned long int keylen);

cdb_find looks for key. If cdb_find returns 0, the database does not contain that key; stop. If cdb_find returns -1, there was a read error; abort.

cdb_datalen returns the length of the data associated with the key. Use it to allocate a pointer p with enough space to hold the data.

cdb_datapos returns the position of the data inside the file. Use it as argument to cdb_read to retrieve the data.

There may be several records under a single key. You can use cdb_findnext to find the next record under this key.

static struct c;

if (cdb_find(&c,key,strlen(key)>0) {
char *buf=alloca(cdb_datalen(&c));
cdb_read(&c,buf,cdb_datalen(&c),cdb_datapos(&c));
write(1,buf,cdb_datalen(&c));
}

cdb_read(3), cdb_init(3), cdb_free(3), cdbmake(1)