# HG changeset patch
# User Markus Brökers <mbroeker@largo.homelinux.org>
# Date 1285425423 -7200
# Node ID f9015072361f2f1c4bafb4ebfaab2f4fc68b9b50
# Parent  0ffa20c26b2dff0da5f56644756d89b9b610c299
simple berkdb usage demo

diff --git a/.gitignore b/.gitignore
--- a/.gitignore
+++ b/.gitignore
@@ -22,3 +22,4 @@
 lsflib/install-sh
 lsflib/missing
 
+berkdb.db
diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -69,6 +69,7 @@
 TARGET += getbits
 TARGET += fun
 TARGET += sts
+TARGET += berkdb
 
 # needs ncursesw
 TARGET  += ncurses
@@ -249,7 +250,7 @@
 
 prog_limit: prog_limit.o set_limit.o
 	@echo Linking $< ...
-	@$(CC) $(LDFLAGS) -o $@ prog_limit.o set_limit.o
+	@$(CC) $(LDFLAGS) -o $@ $?
 
 database: database.c
 	@echo Compiling $< ...
@@ -361,6 +362,10 @@
 	@echo Linking $<...
 	@$(CC) -Wall -O2 -g -ggdb $(LDFLAGS) $< -o $@
 
+berkdb: berkdb.o
+	@echo Linking $<...
+	@$(CC) -Wall -O2 -g -ggdb $(LDFLAGS) $< -o $@ -ldb
+
 .PHONY: beauty clean uninstall
 
 clean:
diff --git a/berkdb.c b/berkdb.c
new file mode 100644
--- /dev/null
+++ b/berkdb.c
@@ -0,0 +1,132 @@
+/**
+ * berkdb.c (C) 2010 Markus Bröker
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <sys/types.h>
+#include <limits.h>
+#include <db.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+DBT key;
+DBT data;
+
+/* initialize the db library and open a db file */
+DB *dbinit (DB * db, char *filename)
+{
+    int ret;
+
+    printf ("Initializing berkley db...\n");
+    if ((ret = db_create (&db, NULL, 0)) != 0) {
+        perror ("db_create");
+        return NULL;
+    }
+
+    bzero (&key, sizeof (key));
+    bzero (&data, sizeof (data));
+
+    printf ("Opening berkdb.db flat database file...\n");
+    if ((ret = db->open (db, NULL, filename, NULL, DB_BTREE, DB_CREATE, 0)) != 0) {
+        perror ("db->open");
+        return NULL;
+    }
+
+    return db;
+}
+
+/* insert a key/value pair into the database */
+int dbinsert (DB * db, int id, char *description)
+{
+    key.data = &id;
+    key.size = sizeof (int);
+
+    data.data = description;
+    data.size = strlen (description) + 1;
+
+    return db->put (db, NULL, &key, &data, DB_NOOVERWRITE);
+}
+
+/* get the associated value from the database for the key 'id' */
+char *dbget (DB * db, int id)
+{
+    key.data = &id;
+    key.size = sizeof (int);
+
+    if (db->get (db, NULL, &key, &data, 0) == 0)
+        return (char *)data.data;
+
+    return NULL;
+}
+
+/* iterate over the db and print all values */
+void dblist (DB * db)
+{
+    int ret;
+    DBC *dbc;
+
+    if (db->cursor (db, NULL, &dbc, 0) != 0) {
+        perror ("db->cursor");
+        return;
+    }
+
+    bzero (&key, sizeof (key));
+    while ((ret = dbc->get (dbc, &key, &data, DB_NEXT)) == 0) {
+        printf ("KEY[%02d] => %s\n", *(int *)key.data, (char *)data.data);
+    }
+
+    if (dbc != NULL) {
+        dbc->close (dbc);
+    } else
+        perror ("dbc");
+}
+
+/* close the db */
+int dbclose (DB * db)
+{
+    if (db != NULL) {
+        printf ("Closing berkley db file...\n");
+        return db->close (db, 0);
+    }
+    return EXIT_FAILURE;
+}
+
+int main (int argc, char **argv)
+{
+    char description[80];
+    int id;
+
+    DB *db = NULL;
+
+    if ((db = dbinit (db, "berkdb.db")) == NULL)
+        return EXIT_FAILURE;
+
+    for (id = 0; id < 100; id++) {
+        sprintf (description, "This is value %d", id);
+
+        switch (dbinsert (db, id, description)) {
+        case 0:
+            printf ("KEY ADDED\n");
+            break;
+        case DB_KEYEXIST:
+            printf ("DUPLICATE KEY %d\n", id);
+            break;
+        default:
+            printf ("Error while storing primary key %d\n", id);
+        }
+    }
+
+    char *value;
+    for (id = 0; id < 10; id++) {
+        if ((value = dbget (db, id)) != NULL)
+            printf ("DB: %s\n", value);
+    }
+
+    dblist (db);
+
+    return dbclose (db);
+}