用C编译包含libmodbus的程序

Question

我是一个C新手…我写了一个非常简单的modbus1.c，其中包括libmodbus(我下载，解压缩，untarred， ./configure'd, make'd和make install'd成功)。

当我尝试制作modbus1.c时，我得到这个:

cc -Wall -g     modbus1.c   -o modbus1
Undefined symbols for architecture x86_64:
  "_modbus_close", referenced from:
      _main in modbus1-6cd135.o
  "_modbus_connect", referenced from:
      _main in modbus1-6cd135.o
  "_modbus_free", referenced from:
      _main in modbus1-6cd135.o
  "_modbus_new_tcp_pi", referenced from:
      _main in modbus1-6cd135.o
  "_modbus_read_bits", referenced from:
      _main in modbus1-6cd135.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [modbus1] Error 1

我运行的是OSX雪豹，以前成功使用make编译过小程序(教程级程序…)这是modbus1.c我试图编译:

#include <stdio.h>
#include <stdlib.h>
#include <modbus.h>
int main(int argc, char *argv[]){
modbus_t *plc_client;
plc_client = modbus_new_tcp_pi("192.168.1.230","502");
if (plc_client == NULL) {
    fprintf(stderr, "Unable to allocate libmodbus contextn");
    return -1;
}
if (modbus_connect(plc_client) == -1) {
    fprintf(stderr, "Connection failed: n");
    modbus_free(plc_client);
    return -1;
}
else if(modbus_connect(plc_client) == 0) {
    printf("MODBUS CONNECTION SUCCESSFULn");
}
uint8_t* catcher = malloc(sizeof(uint8_t));
if(modbus_read_bits(plc_client, 2000, 1, catcher)>0){
    printf("READ SUCCESSFUL");
}
else{
    printf("READ FAILED");
}
free(catcher);
modbus_close(plc_client);
modbus_free(plc_client);
return 0;
}

任何帮助将非常感激!谢谢!

妮可

Answer 1

试试这个

cc -Wall -g modbus1.c -o modbus1 -L/path/to/libmodbus -lmodbus

您应该将/path/to/libmodbus替换为系统中包含libmodbus.dylib的目录的实际路径