《Flex&Bison》例2-2代码

CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
SET(PROJ_NAME fb2-2)
PROJECT(${PROJ_NAME})
find_package(Flex)
FLEX_TARGET(MyScanner ${PROJ_NAME}.txt ${CMAKE_CURRENT_BINARY_DIR}/lexer.c)
ADD_EXECUTABLE(${PROJ_NAME} ${FLEX_MyScanner_OUTPUTS})

%option noyywrap
%{
int chars = 0;
int words = 0;
int lines = 0;

int totchars = 0;
int totwords = 0;
int totlines = 0;
%}
%%

[a-zA-Z]+ { ++words; chars += yyleng; }
\n { ++lines; ++chars; }
. { ++chars; }

%%

int main(int argc, char ** argv)
{
int i;
if (argc<2)
{
yylex();
printf("%8d%8d%8d\n", lines, words, chars);
return 0;
}

for (i=1; i<argc; ++i)
{
FILE * f = fopen(argv[i], "r");
if (!f)
{
perror(argv[i]);
return 1;
}
yyrestart(f);
yylex();
fclose(f);
printf("%8d%8d%8d %s\n", lines, words, chars, argv[i]);
totchars += chars; chars = 0;
totwords += words; words = 0;
totlines += lines; lines = 0;
}

if (argc>1)
{
printf("%8d%8d%8d total\n", totlines, totwords, totchars);
}
return 0;
}