Lex - How to run / compile a lex program on commandline

问题

I am very new to Lex and Yacc. I have a Lex program. Example: wordcount.l

I am using windows and putty.

I am just trying to run this file..

1. Does the wordcount.l file go on the C drive?

2. Do I compile the Lex program and it generates a .c program and then what do I run?

I tried on the command-line: Lex wordcount.l

but I just get file not found...

wordcount.l

%{  
#include <stdlib.h>
#include <stdio.h>

int charCount=0;
int wordCount=0;
int lineCount=0;
%}
%%
\n      {charCount++; lineCount++;}   
[^ \t\n]+   {wordCount++; charCount+=yyleng;}
.       {charCount++;}

%%
main(argc, argv)
int argc;
char** argv;
{           
if (argc > 1)
{
    FILE *file;
    file = fopen(argv[1], "r");
    if (!file)
    {
        fprintf(stderr, "Could not open %s\n", argv[1]);
        exit(1);
    }
    yyin = file;
}

yylex();
printf("%d   %d   %d\n", charCount, wordCount, lineCount);
}

In putty how do I compile and run this program?

回答1:

You first have to go to the directory which the file wordcount.l is in using cd. Then using lex wordcount.l will make the file lex.yy.c. To the run the program you need compile it with a c compiler such as gcc. With gcc you can compile it using gcc -lfl lex.yy.c. This will create a.out which can be run using ./a.out

回答2:

lex file.l
gcc lex.yy.c -ly -ll
./a.out

These also works. I am using this in Ubuntu 14.04.

来源：https://stackoverflow.com/questions/8859710/lex-how-to-run-compile-a-lex-program-on-commandline