2018-10-15 21:07:38 C language

2018-10-15 21:07:38 C language

C language Compiler, magic Magician

1. Under UNIX-like systems (Linux, Mac OS, etc.), executable programs do not have a specific suffix, and the system determines whether an executable program is based on the header information of the file.
2. The inside of an executable is a collection of computer instructions and data, both in binary form, that the CPU can identify directly, without obstacles, but for programmers, they are very obscure and difficult to remember and use.
3. In the early days of computer development, programmers used such binary instructions to write programs, and the Pioneer era had no programming language.
4. For the Cpu,c language code is the heavenly book, does not know, the CPU only knows hundreds of binary forms of instructions.
5. The source file is actually a plain text file with no special formatting inside it.
6. The principle of compiling and linking: The source code has to be compiled (Compile) and link two processes to become executable files. The compiler compiles only one source file at a time, and if the current program contains multiple source files, it needs to be compiled multiple times. The result of each compilation of the compiler is to produce an intermediate file (which can be considered a temporary file) rather than the final executable file. The intermediate files are already very close to the executable, they are both binary, and the internal structure is very similar. Combining all the intermediate files of the current program and the system library (which can be understood temporarily as some of the components in the system) to form the final executable file, the process of this combination is called the link. The software that completes the link function is called the linker (Linker).

2018-10-15 21:07:38 C language