ubuntu下libjson-c库的使用问题备忘

首先安装libjson的c库
#apt-get install libjson0-dev libjson0

安装好后查看/usr/include/json下是否有头文件,有就对了!
gcc -o json-demo -g json-demo.c -std=c99 -I/usr/include/json -L/usr/lib/i386-linux-gnu/ -ljson


注意:
    1、json-demo和json-demo.c參数须要在前面,不能在后面,见错误1
    2、须要就爱如-std=c99,代码中须要,也能够用-std=gnu99,见错误2
    3、-I是json的头文件的路径
    4、-L是json库所在位置,这个路径可能依据系统不同而不同。建议用find / -name "libjson*"找到位置
    5、-ljson不可省略,尽量放在最后,没有这个參数会出现错误1的现象

错误1:
jack@ubuntu:~/json-c$ gcc -I/usr/include/json -L/usr/lib/i386-linux-gnu/ -ljson -std=gnu99 -o json-demo -g json-demo.c 
/tmp/ccaITRtr.o: In function `GetValByKey': 
/home/jack/json-c/json-demo.c:13: undefined reference to `json_object_object_get' 
/home/jack/json-c/json-demo.c:16: undefined reference to `json_object_get_type' 
/home/jack/json-c/json-demo.c:20: undefined reference to `json_object_get_string' 
/home/jack/json-c/json-demo.c:23: undefined reference to `json_object_get_int' 
/tmp/ccaITRtr.o: In function `main': 
/home/jack/json-c/json-demo.c:39: undefined reference to `json_object_new_string' 
/home/jack/json-c/json-demo.c:41: undefined reference to `json_object_get_string' 
/home/jack/json-c/json-demo.c:43: undefined reference to `json_object_to_json_string' 
******

错误2:没有加-std=99參数的错误
jack@ubuntu:~/json-c$ gcc -o json-demo -g json-demo.c -I/usr/include/json -L/usr/lib/i386-linux-gnu/ -ljson 
json-demo.c: In function ‘main’: 
json-demo.c:87:2: error: ‘for’ loop initial declarations are only allowed in C99 mode 
json-demo.c:87:2: note: use option -std=c99 or -std=gnu99 to compile your code


原文地址:https://www.cnblogs.com/zfyouxi/p/5261998.html