stmr-cli.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "stmr.h"

/* Utility to detect if `character` is a letter. */
#define IS_LETTER(character) (isupper(character) || islower(character))

/* Pointer to memory allocation. */
static char *value;

/* Initial value for `indexMax`. */
#define BASE_INDEX 50

/* Maximum offset in `value`. */
static int indexMax = BASE_INDEX;

/* Increase memory. */
static void
increaseValue() {
  char *newValue;
  int index;

  indexMax *= 2;

  newValue = (char *) malloc(indexMax + 1);

  index = -1;

  while (++index < indexMax) {
    newValue[index] = value[index];
  }

  free(value);

  value = newValue;
}

/* Tokenise and stem a file */
static void
stemFile(FILE *file) {
  int character;
  int index;

  while (TRUE) {
    character = getc(file);

    if (character == EOF) {
      return;
    }

    if (IS_LETTER(character)) {
      index = 0;

      while (TRUE) {
        if (index == indexMax) {
          increaseValue();
        }

        character = tolower(character);

        value[index] = character;

        index++;

        character = getc(file);

        if (!IS_LETTER(character)) {
          ungetc(character, file);
          break;
        }
      }

      value[stem(value, 0, index - 1) + 1] = 0;

      /* The previous line calls the stemmer and
       * uses its result to zero-terminate the
       * string in `value`. */
      printf("%s", value);
    } else {
      putchar(character);
    }
  }
}

/**
 * Evaluate a word.
 */

static void
evaluate(const char *input) {
  value = strdup(input);

  value[stem(value, 0, strlen(value) - 1) + 1] = 0;

  printf("%s\n", value);
}

/* CLI. */
int
main(int argc, char **argv) {
  char *arg;
  FILE *input;
  int index;

  arg = argv[1];

  if (argc == 2) {
    if (!strcmp(arg, "-v") || !strcmp(arg, "--version")) {
      printf("%s", "0.1.0\n");

      return EXIT_SUCCESS;
    }

    if (!strcmp(arg, "-h") || !strcmp(arg, "--help")) {
      printf("%s", "\n");
      printf("%s", "  Usage: stmr [options] file\n");
      printf("%s", "\n");
      printf("%s", "  Options:\n");
      printf("%s", "\n");
      printf("%s", "    -h, --help           output usage information\n");
      printf("%s", "    -v, --version        output version number\n");
      printf("%s", "    -e, --eval string    output stemmed word\n");
      printf("%s", "\n");
      printf("%s", "  Usage:\n");
      printf("%s", "\n");
      printf("%s", "  # stem a word\n");
      printf("%s", "  $ stmr -e nationalism\n");
      printf("%s", "  # nation\n");
      printf("%s", "\n");
      printf("%s", "  # print stems\n");
      printf("%s", "  $ stmr in.txt\n");
      printf("%s", "\n");
      printf("%s", "  # write stems to out.txt\n");
      printf("%s", "  $ stmr in.txt > out.txt\n");
      printf("%s", "\n");
      printf("%s", "  # stdin and stdout\n");
      printf("%s", "  $ echo \"Internationalise\" | stmr\n");
      printf("%s", "  # internationalis\n");
      printf("%s", "\n");

      return EXIT_SUCCESS;
    }
  }

  if (argc > 1 && (!strcmp(arg, "-e") || !strcmp(arg, "--eval"))) {
    arg = argv[2];

    if (arg == NULL) {
      fprintf(stderr, "stmr: -e requires an argument\n");

      exit(EXIT_FAILURE);
    }

    evaluate(arg);

    return EXIT_SUCCESS;
  }

  value = (char *) malloc(indexMax + 1);

  if (argc < 2) {
    stemFile(stdin);
  } else {
    index = 0;

    while (++index < argc) {
      arg = argv[index];

      input = fopen(arg, "r");

      if (NULL == input) {
        fprintf(stderr, "Unable to open '%s': %s\n", arg, strerror(errno));
        exit(EXIT_FAILURE);
      }

      stemFile(input);
    }
  }

  free(value);

  return EXIT_SUCCESS;
}