Linux系统下C/C++编程
参考视频
Linux下C/CPP开发基础
gcc库使用
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# vim main.cpp
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat main.cpp
#include静态链接库 .a
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ -c mymath.cpp -o mymath.o
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ll mymath.o
-rw-r--r-- 1 root root 1240 Mar 26 19:33 mymath.o
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ar rcs libmymath.a mymath.o
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ -c main.cpp -o main.o # 编译
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ main.o -L . -l mymath -o main # 链接
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./main
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动态链接库 .so
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ mymath.cpp -shared -o libmymath.so
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ main.o -L . -l mymath -o main
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./main
./main: error while loading shared libraries: libmymath.so: cannot open shared object file: No such file or directory
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat /etc/ld.so.conf
include /etc/ld.so.conf.d/*.conf
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# echo "$(pwd)" >> .so: cannot open shared object file: No such file or directory
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat
-bash: root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp#: No such file or directory
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# echo "$(pwd)" >> /etc/ld.so.conf
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat /etc/ld.so.conf
include /etc/ld.so.conf.d/*.conf
/root/cpp
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ldconfig
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./main
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jsoncpp
jsoncpp usage
#下载 jsoncpp 源码
git clone https://github.com/open-source-parsers/jsoncpp.git
#进到目录
cd jsoncpp-master
#创建目录
mkdir -p build/release
#进到编译目录
cd build/release
#使用 cmake 进行编译
cmake -DCMAKE_BUILD_TYPE=release -DBUILD_STATIC_LIBS=ON \
-DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_INCLUDEDIR=include/jsoncpp \
-DARCHIVE_INSTALL_DIR=. -G "Unix Makefiles" ../..
#编译和安装
make && make install
examples
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# vim jsoncpp_demo01.c
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat jsoncpp_demo01.c
#include const jsonReader(readerBuilder.newCharReader());
res = jsonReader->parse(info.c_str(), info.c_str() + info.length(), &root, &errs);
if (!res || !errs.empty())
{
std::cout << "parseJson err. " << errs << std::endl;
return false;
}
// printJsoncpp(root);
return true;
}
bool JsoncppDecodeOld(const std::string &strJson)
{
if (strJson.empty())
return false;
bool res;
Json::Value root;
Json::Reader jsonReader;
res = jsonReader.parse(strJson, root);
if (!res)
{
std::cout << "jsonReader.parse err. " << std::endl;
return false;
}
// printJsoncpp(root);
return true;
}
const char *strCjson = "{ \
\"name\": \"milo\", \
\"age\": 80, \
\"languages\": [\"C++\", \"C\"],\
\"phone\": { \
\"number\": \"186****3143\", \
\"type\": \"home\" \
}, \
\"books\": [{ \
\"name\": \"Linux kernel development\", \
\"price\": 7.700000 \
}, { \
\"name\": \"Linux server development\", \
\"price\": 8 \
}], \
\"vip\": true, \
\"address\": null \
} \
";
#define TEST_COUNT 100000
int main()
{
std::string jsonStrNew;
std::string jsonStrOld;
jsonStrNew = JsoncppEncodeNew();
// JsoncppEncodeNew size: 337
std::cout << "JsoncppEncodeNew size: " << jsonStrNew.size() << std::endl;
std::cout << "JsoncppEncodeNew string: " << jsonStrNew << std::endl;
JsoncppDecodeNew(jsonStrNew);
jsonStrOld = JsoncppEncodeOld();
// JsoncppEncodeOld size: 248
std::cout << "\n\nJsoncppEncodeOld size: " << jsonStrOld.size() << std::endl;
std::cout << "JsoncppEncodeOld string: " << jsonStrOld << std::endl;
JsoncppDecodeOld(jsonStrOld);
Json::Value root = JsoncppEncodeOldGet();
Json::FastWriter writer;
std::cout << "writer:\n" << std::endl;
std::string jsonStr = writer.write(root);
std::cout << "\n\njsonStr string: " << jsonStrOld << std::endl;
#if 1
uint64_t startTime;
uint64_t nowTime;
startTime = getNowTime();
std::cout << "jsoncpp encode time testing" << std::endl;
for(int i = 0; i < TEST_COUNT; i++)
{
JsoncppEncodeNew();
}
nowTime = getNowTime();
std::cout << "jsoncpp encode " << TEST_COUNT << " time, need time: "
<< nowTime-startTime << "ms" << std::endl;
startTime = getNowTime();
std::cout << "\njsoncpp encode time testing" << std::endl;
for(int i = 0; i < TEST_COUNT; i++)
{
JsoncppEncodeOld();
}
nowTime = getNowTime();
std::cout << "jsoncpp encode " << TEST_COUNT << " time, need time: "
<< nowTime-startTime << "ms" << std::endl;
startTime = getNowTime();
std::cout << "\njsoncpp decode time testing" << std::endl;
for(int i = 0; i < TEST_COUNT; i++)
{
JsoncppDecodeNew(jsonStrNew);
}
nowTime = getNowTime();
std::cout << "jsoncpp decode " << TEST_COUNT << " time, need time: "
<< nowTime-startTime << "ms" << std::endl;
startTime = getNowTime();
std::cout << "\njsoncpp decode time testing" << std::endl;
for(int i = 0; i < TEST_COUNT; i++)
{
JsoncppDecodeOld(jsonStrNew);
}
nowTime = getNowTime();
std::cout << "jsoncpp decode " << TEST_COUNT << " time, need time: "
<< nowTime-startTime << "ms" << std::endl;
#endif
return 0;
}
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# g++ jsoncpp_speed.cpp -o jsoncpp_speed -ljsoncpp -std=c++11
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./jsoncpp_speed
JsoncppEncodeNew size: 345
JsoncppEncodeNew string: {
"address" : "yageguoji",
"age" : 80,
"books" :
[
{
"name" : "Linux kernel development",
"price" : 7.7000000000000002
},
{
"name" : "Linux server development",
"price" : 8.0
}
],
"languages" :
[
"C++",
"Java"
],
"name" : "milo",
"phone" :
{
"number" : "186****3143",
"type" : "home"
},
"vip" : true
}
JsoncppEncodeOld size: 253
JsoncppEncodeOld string: {"address":"yageguoji","age":80,"books":[{"name":"Linux kernel development","price":7.6999998092651367},{"name":"Linux server development","price":8.0}],"languages":["C++","Java"],"name":"milo","phone":{"number":"186****3143","type":"home"},"vip":true}
JsoncppEncodeOldGet:
writer:
jsonStr string: {"address":"yageguoji","age":80,"books":[{"name":"Linux kernel development","price":7.6999998092651367},{"name":"Linux server development","price":8.0}],"languages":["C++","Java"],"name":"milo","phone":{"number":"186****3143","type":"home"},"vip":true}
jsoncpp encode time testing
jsoncpp encode 100000 time, need time: 1435ms
jsoncpp encode time testing
jsoncpp encode 100000 time, need time: 789ms
jsoncpp decode time testing
jsoncpp decode 100000 time, need time: 988ms
jsoncpp decode time testing
jsoncpp decode 100000 time, need time: 643ms
视频中
main.cpp
#include 
makefile
makefile
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# make
g++ -o main mymath.cpp main.cpp
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./main
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root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# vim makefile
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# make clean && make
rm -f main
g++ -o main mymath.cpp main.cpp
root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# ./main
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root@iZuf6ir9zx8jfk2vinfpllZ:~/cpp# cat makefile
cpp=$(wildcard *.cpp)
obj=main
$(obj):$(cpp)
g++ -o $@ $^
.PHONY: clean
clean:
rm -f $(obj)
cmake
CMake 良心教程，教你从入门到入魂 - 程序员阿德的文章 - 知乎
# 目录下有CMakeLists.txt
cmake .
# 生成makefile文件
make
# 自动编译
example
CMakeLists.txt
cmake_minimum_required(VERSION 3.5)
# set the project name
project(Tutorial LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
# add the executable
add_executable(${PROJECT_NAME} tutorial.cpp)
tutorial.cpp
#include 
视频
cmake 用于 jsoncpp/example
cd ..
g++ ./stringWrite/stringWrite.cpp -ljsoncpp -std=c++11 -o stringWrite
g++ ./stringWrite/stringWrite.cpp -ljsoncpp -std=c++11 -o ./stringWrite/stringWrite.o
./stringWrite/stringWrite.o
g++ ./streamWrite/streamWrite.cpp -ljsoncpp -std=c++11 -o ./streamWrite/streamWrite.o
vim ./streamWrite/streamWrite.cpp
cat ./streamWrite/streamWrite.cpp
g++ ./streamWrite/streamWrite.cpp -ljsoncpp -std=c++11 -o ./streamWrite/streamWrite.o
./streamWrite/streamWrite.o
cat ./readFromString/readFromString.cpp
