bsort.c

/*
	Author:			Juan Alvarado
	Panther ID:		3367805
	Description:	Write a C program that sorts the lines of some input
	Usage:			bstsort [-c] [-o output_file_name] [input_file_name]
	Originality:	I affirm that this program is entirely my own work and 
			none of it is the work of any other person
*/

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

/***********************
 * Type Declarations
 */
typedef struct TreeNode {
  char key[100];
  struct TreeNode* left;
  struct TreeNode* right;
} TreeNode;

/***********************
 * Function Signature Declarations
 */
int read_input_from_stdin_to_tree();
int read_input_from_file_to_tree(char* in_file_name);

int comp_str_case(char string1[], char string2[]);
int comp_str_ignore_case(char string1[], char string2[]);

TreeNode* add(TreeNode* node, char key[]);
void printInorder(TreeNode* node);
void freePostorder(TreeNode* root);

/***********************
 * Main Program
 */

int case_sensitive_flag = 0;
char outfileflag = 0;
FILE* outfile;
TreeNode* root_node;

int
main(int argc, char **argv)
{
	extern char *optarg;
	extern int optind;
	int c, err = 0; 
	char *outfilename;
	static char usage[] = "Usage: %s [-c] [-o output_file_name] [input_file_name]\n";
	TreeNode* node;

	while ((c = getopt(argc, argv, "co:")) != -1)
		switch (c) {
		case 'c':
			case_sensitive_flag = 1;
			break;
		case 'o':
			outfileflag = 1;
			outfilename = optarg;
			outfile = fopen(outfilename, "w");
			break;
		case '?':
			err = 1;
			break;
		}

	// no input_file_name given
	if((optind+1) > argc) {
		// Process from stdin
		int stdinread = read_input_from_stdin_to_tree();
	} else if (err) {
		// incorrect use of bsort. Print usage.
		fprintf(stderr, usage, argv[0]);
		exit(1);
	}
	else {
		// Process from file
		char* input_file_name;
		input_file_name = argv[optind];
		int fileread = read_input_from_file_to_tree(input_file_name);
	}

	printInorder(root_node);
	if(outfileflag == 1) fclose(outfile);
	freePostorder(root_node);
	exit(0);
}


/**************************************
 * FUNCTION DEFINITIONS
 **************************************/


/***************
 * Reading Functions 
 */
int read_input_from_stdin_to_tree() {
	char strbuffer[100];
	while(fgets(strbuffer, sizeof(strbuffer), stdin) != NULL && strbuffer[0] != '\n') {
		root_node = add(root_node, strbuffer);
	}
	return 0;
}

int read_input_from_file_to_tree(char* in_file_name) {
	char strbuffer[100];
	FILE* infile;
	infile = fopen(in_file_name, "r");
	if (infile == NULL) {
		fprintf(stderr, "Error opening file.\n");
		return(-1);
	}
	while(fgets(strbuffer, sizeof(strbuffer), infile) != NULL && strbuffer[0] != '\n') {
		root_node = add(root_node, strbuffer);
	}
	fclose(infile);
	return 0;
}

/***********************
 * Binary Search Tree Implementation
 */
TreeNode* add(TreeNode* node, char key[]) {
	if (node == NULL) {
		node = (TreeNode*) malloc(sizeof (TreeNode));
		if (node == NULL) {
			return NULL;
		}
		strcpy(node->key, key);
		node->left = NULL;
		node->right = NULL;
		return node;
	}
	// Comparison Based on case setting;
	int comparison;
	if (case_sensitive_flag > 0)
		comparison = comp_str_case(node->key, key);
	else 
		comparison = comp_str_ignore_case(node->key, key);
	if (comparison > 0) {
		node->left = add(node->left, key);
	}
	else {
		node->right = add(node->right, key);
	}
	return node;
}

void printInorder(TreeNode* node) {
	if (node == NULL) {
		return;
	}
	printInorder(node->left);
	if (outfileflag == 1) {
		fprintf(outfile, "%s", node->key);
	}
	else {
		printf("%s", node->key);
	}
	printInorder(node->right);
}

void freePostorder(TreeNode *root) {
    if (root == NULL) {
        return;
    }
    freePostorder(root->left);
    freePostorder(root->right);
    free(root);
}

/******************
 *  Utilites
 */
int comp_str_case(char string1[], char string2[]) {
    int i = 0;
    while(string1[i] == string2[i]) {
        if(string1[i] == '\0' || string2[i] == '\0') break;
        i++;
    } 

    if(string1[i] == '\0' && string2[i]=='\0')
        return 0;
    else if(string1[i] > string2[i])
        return 1;
    else if(string1[i] < string2[i])
        return -1;
}

int comp_str_ignore_case(char string1[], char string2[]) {
    int i = 0;
    while(tolower(string1[i]) == tolower(string2[i])) {
        if(string1[i] == '\0' || string2[i] == '\0') break;
        i++;
    } 

    if(string1[i] == '\0' && string2[i]=='\0')
        return 0;
    else if(tolower(string1[i]) > tolower(string2[i]))
        return 1;
    else if(tolower(string1[i]) < tolower(string2[i]))
        return -1;
}