标签：lib 目录 ini led cal 遇到 test linux 空格
main.cpp
#include<stdio.h> #include<stdlib.h> #include"mysqlInterface.h" int main() { CMysqlInterface mysqlObj; mysqlObj.connect(); return 0; }
mysqlInterface.h
class CMysqlInterface { public: CMysqlInterface(); ~CMysqlInterface(); int connect(); private: MYSQL* mysqlPtr; };
mysqlInterface.cpp
#include"mysqlInterface.h" CMysqlInterface::CMysqlInterface() { printf("CMysqlInterface\n"); mysqlPtr = NULL; mysqlPtr = mysql_init(NULL); if(!mysqlPtr) { printf("mysql_init failed\n"); } } CMysqlInterface::~CMysqlInterface() { mysql_close(mysqlPtr); mysqlPtr = NULL; } int CMysqlInterface::connect() { int iRet = -1; mysql_real_connect(mysqlPtr,"localhost","root","csql","child",0,NULL,0); if(!mysqlPtr) { printf("connect failed\n"); } else { printf("connect success\n"); iRet = 0; } return iRet; }
Makefile：
Makefile文件 test : main.o mysqlInterface.o g++ main.o mysqlInterface.o -o test -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient main.o:main.cpp g++ -c main.cpp -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient mysqlInterface.o : mysqlInterface.cpp g++ -c mysqlInterface.cpp -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient .PHONY:clean clean: rm -f main.o mysqlInterface.o test
执行结果：
make
g++ -c main.cpp -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient
g++ -c mysqlInterface.cpp -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient
g++ main.o mysqlInterface.o -o test -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient
./test
CMysqlInterface
connect success
程序运行成功
Makefile升级版：
src = $(wildcard ./*cpp) obj = $(patsubst %.cpp , %.o , $(src)) target = test CC = g++ $(target) : $(obj) $(CC) $(obj) -o $(target) -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient %.o: %.cpp $(CC) -c $< -o $@ -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient .PHONY:clean clean: rm -f $(obj)$(target)
文件解释：
src = $(wildcard ./*cpp)
扩展通配符：搜索指定文件。
这句话代表的意思是再当前目录下搜索所有的 .cpp文件并赋值给变量 src。函数执行结束后，src的值就是 main.cp 和 mysqlInterface.cpp
obj = $(patsubst %.cpp , %.o , $(src))
patsubst，替换通配符，按照指定规则做替换。
此行代码的意思的是将src里的每个.cpp文件 都替换成 .o文件赋值给 obj变量。
这句话还可以替换成obj = $(src: %.c = %.o) //也是将src里的每个文件都是.c替换.o
Makefile再升级：
src = $(wildcard ./*cpp) obj = $(patsubst %.cpp , %.o , $(src)) target = test CC = g++ $(target) : $(obj) $(CC) $(CFLAGS) $(LDFLAGS) $(LIBS) $(obj) -o $(target) -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient %o: %.cpp $(CC) $(CFLAGS) -c $< -o $@ -I/usr/include/mysql -L/usr/lib/mysql/ -lmysqlclient .PHONY:clean clean: rm -f $(target) $(obj)
遇到的bug：
obj = $(patsubst %.cpp , %.o , $(src))
%.cpp,%.o不能有空格
如果有空格，那obj的值还是.cpp文件，不会转化为.o文件
%o: %.cpp
如果%.o少了，会报mysql.h找不到的错误
In file included from main.cpp:3:0:
mysqlInterface.h:2:18: fatal error: mysql.h: 没有那个文件或目录
#include"mysql.h"
^
compilation terminated.
成功版本：
CFLAGS := -g target := test INCLUDE = -I /usr/include/mysql lib = -lmysqlclient dirlib = -L /usr/lib/mysql/ src = $(wildcard *.cpp) objs = $(patsubst %.cpp,%.o,$(src)) all: $(target) %.o: %.cpp #g++ $(CFLAGS) $(INCLUDE) $(lib) $(dirlib) -c $< -o $@ g++ $(CFLAGS) $(INCLUDE) $(lib) $(dirlib) -c $< -o $@ $(target) : $(objs) g++ $(CFLAGS) $(objs) $(dirlib) $(lib) -o $(target) $(INCLUDE) .PHONY:clean clean: rm -f $(target) $(obj)
如果make的文件名是Makefile或makefile，直接执行make
如果是别的，比如Makefile1，就可以执行make -f Makefile1
执行结果:
exbot@ubuntu:~/wangqinghe/MySql/20190621/01/01$ make -f Makefile1
#g++ -g -I /usr/include/mysql -lmysqlclient -L /usr/lib/mysql/ -c main.cpp -o main.o
g++ -g -I /usr/include/mysql -lmysqlclient -L /usr/lib/mysql/ -c main.cpp -o main.o
#g++ -g -I /usr/include/mysql -lmysqlclient -L /usr/lib/mysql/ -c mysqlInterface.cpp -o mysqlInterface.o
g++ -g -I /usr/include/mysql -lmysqlclient -L /usr/lib/mysql/ -c mysqlInterface.cpp -o mysqlInterface.o
g++ -g main.o mysqlInterface.o -L /usr/lib/mysql/ -lmysqlclient -o test -I /usr/include/mysql
程序运行结果;
exbot@ubuntu:~/wangqinghe/MySql/20190621/01/01$ ./test
CMysqlInterface
connect success
标签：lib 目录 ini led cal 遇到 test linux 空格
原文地址：https://www.cnblogs.com/wanghao-boke/p/11067013.html
