token.c

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

#include "vect.h"

// Tokenizes the inputs
vect_t *parseInput(char *input);

// Handles cases that are in quotes
int handle_string(int i, char *input, vect_t *output);

// Checks if the given character is a special character
int isSpecialChar(char c);

// Checks if the given character is a special character
int isSpecialChar(char c) {
  if (c == '(' || c == ')'
      || c == '<' || c == '>'
      || c == ';' || c == '|'
      || c == ' ') {
    return 1;
  }
  return 0;
}

vect_t *parseInput(char *input) {

  // Keeps track of the string not seperated by space
  char *buffer = (char *) malloc(255);

  // Keeps track of the last character within the string
  int bufferIdx = 0;

  vect_t *output = vect_new();
  for (int i = 0; i < strlen(input); i++) {
    char curChar = input[i];

    // Checks if a special case was encountered to add all the temporarily stored string into the vector
    if (bufferIdx > 0
        && (isSpecialChar(curChar)
            || (curChar == '\\' && (input[i + 1] == 'n' || input[i + 1] == 't'))
            || (curChar == '\"' || (curChar == '\\' && input[i + 1] == '\"'))
            || curChar == '\n' || curChar == '\t')) {
      buffer[bufferIdx] = '\0';
      vect_add(output, buffer);
      bufferIdx = 0;
    } else if (i == strlen(input) - 1
               && !(isSpecialChar(curChar)
                    || (curChar == '\\' && (input[i + 1] == 'n' || input[i + 1] == 't'))
                    || (curChar == '\"' || (curChar == '\\' && input[i + 1] == '\"'))
                    || curChar == '\n' || curChar == '\t')) {
      buffer[bufferIdx] = curChar;
      buffer[bufferIdx + 1] = '\0';
      bufferIdx = 0;
      vect_add(output, buffer);
    }

    // Checks if the character on its own is a token
    if (curChar == '(' || curChar == ')'
        || curChar == '<' || curChar == '>'
        || curChar == ';' || curChar == '|') {
      vect_add(output, &curChar);
      continue;
    }

    // Checks if it is an enter or a tab
    if ((curChar == '\\' && (input[i + 1] == 'n' || input[i + 1] == 't')) || curChar == '\n' || curChar == '\t') {
      i++;
      continue;
    }

    // Checks if it is a quote
    if ((curChar == '\\' && input[i + 1] == '\"') || curChar == '\"') {
      i = handle_string(i + 1, input, output);
      continue;
    }

    // Checks if it is a space
    if (curChar == ' ') {
      continue;
    }

    buffer[bufferIdx] = curChar;
    bufferIdx++;
  }

  free(buffer);
  return output;
}

// Handles cases that are in quotes
int handle_string(int i, char *input, vect_t *output) {

  if (input[i] == '\"') {
    i++;
  }

  char *buffer = (char *) malloc(255 * sizeof(char *));
  int bufferIdx = 0;

  while (input[i] != '\"') {
    char curChar = input[i];
    buffer[bufferIdx] = curChar;
    bufferIdx++;
    i++;
  }

  if (buffer[bufferIdx - 1] == '\\') {
    buffer[bufferIdx - 1] = '\0';
  } else {
    buffer[bufferIdx] = '\0';
  }

  vect_add(output, buffer);
  free(buffer);
  return i;
}