Getting Started with Lex in the Windows environment

Download deployment:

https://sourceforge.net/projects/winflexbison/download Win_flex_bison-latest.zip, unzip to C:\win_flex_bison

To edit a lex file:

Lex files use "percent" separated into three segments, namely: set a paragraph, the rules are short, user code section;

Here is a simple, ready-made example:

%{int num_lines = 0, num_chars = 0;%}%%\n      ++num_lines; ++num_chars;.       ++num_chars;%%int Yywrap () {return 1;}

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Compile the Lex file:

>c:\win_flex_bison\win_flex.exe--wincompat a.l//Wincompat parameters cannot be saved

No news is good news, generated file lex.yy.c

Import VS2013 Project:

To create a new WIN32 console project using VS2013

Copy the lex.yy.c to the project and rename it to Lex.yy.cpp to join the project

Add in head: #include "stdafx.h"

The main function source file is as follows:

//testbench.cpp: Defines the entry point of the console application. //#include"stdafx.h"#include<stdio.h>extern intNum_lines;extern intNum_chars;externFILE *Yyin;extern intYylex (void);int_tmain (intARGC, _tchar*argv[]) {fopen_s (&yyin,"D:\\STUDY\\FLEXBISON\\LINECOUNTER\\A.L","R");    Yylex ();    Fclose (Yyin); printf ("lines =%d, chars =%d\n", Num_lines, num_chars); return 0;}

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Compile and run, you are done.

Getting Started with Lex in the Windows environment