Linux C/C++ 编译参数详解：-I, -l, -L | 极客日志

Linux C/C++ 编译参数详解：-I, -l, -L | 极客日志

# 编译时去 ./include 目录查找头文件 gcc -I./include -c src/main.c -o src/main.o

# 正确：依赖方(main.o) 在前，提供方(-lmylib) 在后 gcc main.o -lmylib -o app # 错误：可能报 "undefined reference" 错误 gcc -lmylib main.o -o app

# 在 ./lib 目录下查找 libmylib.so 进行链接 gcc src/main.o -L./lib -lmylib -o main_app

graph LR
A[Source Code (.c)] --> B(Preprocessed (.i))
E[Headers (.h)] -.-> B
B --> C{Compile/Assemble}
C --> D[Object File (.o)]
D --> G(Linker ld)
F[Libraries (.a/.so)] -.-> G
G --> H[Executable]

graph TD
A[GCC Driver] -->| -I | B[Headers Search Path]
B --> C[mylib.h]
A -->| -L /path/to/lib | D[Library Search Path]
D --> E[libmylib.so / libmylib.a]
A -->| -l mylib | E

project/
├── include/
│   └── mylib.h
├── lib/
│   └── (空，用于存放编译出的库)
└── src/
    ├── main.c
    └── mylib.c

gcc -shared -fPIC -I./include -o lib/libmylib.so src/mylib.c

gcc -I./include -L./lib -o main_app src/main.c -lmylib -Wl,-rpath,./lib

./main_app # 输出：Hello from custom library! ldd main_app # 输出显示：libmylib.so => ./lib/libmylib.so ...