Compiler Error : Undefined symbols for architecture x86_64 - c++

Question

Compiler failed with error Undefined symbols for architecture x86_64
macOS 10.15.6 Catalina
compiler
g++-11 --version
g++-11 (Homebrew GCC 11.2.0_3) 11.2.0
error :
Undefined symbols for architecture x86_64:
"__ZN4ssdb6Client7connectEPKci", referenced from:
_main in cciJLzzz.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
.cpp
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <vector>
#include "SSDB_client.h"
int main(int argc, char **argv){
const char *ip = (argc >= 2)? argv[1] : "127.0.0.1";
int port = (argc >= 3)? atoi(argv[2]) : 8888;
ssdb::Client *client = ssdb::Client::connect(ip, port);
if(client == NULL){
printf("fail to connect to server!\n");
}else{
printf("ssdb client\n");
}
delete client;
return 0;
}
is there a notation issue here ?
namespace ssdb, class client ..
if I replace this line :
ssdb::Client *client = ssdb::Client::connect(ip, port);
with :
ssdb::Client *client = 0;
the compiler works and I don't get this error ..
the above code is from ssdb docs :
ssdb docs
ssdb docs C++ client
I would like to connect to the ssdb server ..
EDIT :
For command requests
g++ -o hello-ssdb hello-ssdb.cpp libssdb-client.a
..in libssdb-client.a(SSDB_impl.o)
..in libssdb-client.a(link.o)
ld: symbol(s) not found for architecture x86_64
g++ -o hello-ssdb.cpp hello-ssdb libssdb-client.a
ld: can't link with a main executable file
Regarding libssdb-client.a
ar t libssdb-client.a
__.SYMDEF
SSDB_impl.o
bytes.o
link.o
link_addr.o
..
using ssdb for long time but with php client. fine in most cases, but there is something I have to iterate many many times .. and with C/C++ I should be able to save a lot of time ..
..
Workaround :
package main
import (
"fmt"
"os"
"ssdb"
)
func main() {
fmt.Println("We will use Golang .. \n")
ip := "127.0.0.1"
port := 8888
db, err := ssdb.Connect(ip, port)
if err != nil {
os.Exit(1)
}
defer db.Close()
var val interface{}
keys := []string{}
keys = append(keys, "c");
keys = append(keys, "d");
val, err = db.Do("multi_get", "a", "b", keys);
fmt.Printf("%s\n", val);
db.Set("a", "xxx")
val, err = db.Get("a")
fmt.Printf("%s\n", val)
fmt.Printf("----\n");
return
}

Answer 1

Note that in the documentation for ssdb, they include a libssdb.a that you need to link:
g++ -o hello-ssdb hello-ssdb.cpp libssdb.a
This would have the implementation of all the code for ssdb and is why you are seeing the problem you are seeeing.