wc.mapper.c

Go to the documentation of this file.

/** \file wc.mapper.c
    \brief Example for KMR shell command pipeline.  It is a mapper
    for word count. */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

/** Maximum line length. */
#define LINELEN 32767

/** \brief Ignore characters.
    These characters are replaced to a space character. */

//static char ignoreChar[] = { ',', '.', '\t', '?', '"', '!', '$', '/', '<', '>', ':', ';', '[', ']', '(', ')', '-' };
static char ignoreChar[] = { '\t' };

/** \breif Replace Character.
    Replace ignore characters to a space character.  */

static inline void ReplaceChar(char *wp)
{
    while (*wp != 0) {
        /* uncomment if ignore case. */
        // if (isalpha(*wp) && isupper(*wp))
        // *wp = tolower(*wp);
        for (int i = 0; i < (int)sizeof(ignoreChar); i++) {
            if (*wp == ignoreChar[i]) {
                *wp = ' ';
                break;
            }
        }
        wp++;
    }
}

/** \brief Main function.
    Read line from stdin, replace character, separate word by space,
    and output "WORD 1" to stdout.  */

int
main(int argc, char *argv[])
{
    char line[LINELEN];

    while (fgets(line, sizeof(line), stdin) != NULL) {
        char *wtop = NULL, *cp = line;
        int len = (int)strlen(line);
        ReplaceChar(line);
        while ((cp - line) < len) {
            while (*cp == ' ') {
                cp++;                   // skip space
            }
            if (*cp == '\n' || *cp == '\0') {
                break;                  // end of line or buffer end.
            }
            wtop = cp;
            while (*cp != ' ' && *cp != '\n' && *cp != '\0') {
                cp++;
            }
            *cp = '\0';
            printf("%s 1\n", wtop);
            cp++;
        }
    }
    return 0;
}