FLEX

cat

%%
.|\n    ECHO;
%%

wc

%{
/*
 * ch2-03.l
 *
 * The word counter example for multiple files
 *
 */

unsigned long charCount = 0, wordCount = 0, lineCount = 0;

#undef yywrap    /* sometimes a macro by default */

%}

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

char **fileList;
unsigned currentFile = 0;
unsigned nFiles;
unsigned long totalCC = 0;
unsigned long totalWC = 0;
unsigned long totalLC = 0;

main(argc,argv)
int argc;
char **argv;
{
        FILE *file;

        fileList = argv+1;
        nFiles = argc-1;

        if (argc == 2) {
                /*
                 * we handle the single file case differently from
                 * the multiple file case since we don't need to
                 * print a summary line
                 */
                currentFile = 1;
                file = fopen(argv[1], "r");
                if (!file) {
                    fprintf(stderr,"could not open %s\n",argv[1]);
                    exit(1);
                }
                yyin = file;
        }
        if (argc > 2)
                yywrap();    /* open first file */

        yylex();
        /*
         * once again, we handle zero or one file
         * differently from multiple files.
         */
        if (argc > 2) {
                printf("%8lu %8lu %8lu %s\n", lineCount, wordCount,
                    charCount, fileList[currentFile-1]);
                totalCC += charCount;
                totalWC += wordCount;
                totalLC += lineCount;
                printf("%8lu %8lu %8lu total\n",totalLC, totalWC, totalCC);
        } else
                printf("%8lu %8lu %8lu\n",lineCount, wordCount, charCount);

        return 0;
}

/*
 * the lexer calls yywrap to handle EOF conditions (e.g., to
 * connect to a new file, as we do in this case.)
 */

yywrap()
{
    FILE *file=NULL;

    if ((currentFile != 0) && (nFiles > 1) && (currentFile < nFiles)) {
        /*
         * we print out the statistics for the previous file.
         */
        printf("%8lu %8lu %8lu %s\n", lineCount, wordCount,
            charCount, fileList[currentFile-1]);
        totalCC += charCount;
        totalWC += wordCount;
        totalLC += lineCount;
        charCount = wordCount = lineCount = 0;
        fclose(yyin);    /* done with that file */
    }

    while (fileList[currentFile] != (char *)0) {
        file = fopen(fileList[currentFile++], "r");
        if (file != NULL) {
            yyin = file;
            break;
        }
        fprintf(stderr,
            "could not open %s\n",
            fileList[currentFile-1]);
    }
    return (file ? 0 : 1);    /* 0 means there's more input */
}