/******************************************************
*
* file d:\huffman.c
*
*
******************************************************/
#include "d:\lsu\cujhuff.h"
main(argc, argv)
int argc;
char *argv[];
{
char input_file_name [80],
output_file_name [80],
r[80];
int i, j;
struct item_struct item_array[LENGTH];
struct header_struct file_header;
if(argc < 3){
printf("\nHUFFMAN> You did not enter enough file names.");
printf("\nHUFFMAN> Try again: huffman in_file_name out_file_name");
printf("\nHUFFMAN> or");
printf("\nHUFFMAN> huffman destination_file packed_file d");
exit(1);
}
/*
If there are four arguments then you are decompressing
the compressed input file to a full size output file.
*/
if(argc >= 4){
strcpy(output_file_name, argv[1]);
strcpy(input_file_name, argv[2]);
decode_compressed_file(input_file_name,
output_file_name,
item_array,
&file_header);
}
else{ /* else you compress the full size input file and write
out a compressed output file */
strcpy(input_file_name, argv[1]);
strcpy (output_file_name, argv[2]);
read_input_file_and_create_histogram(input_file_name, item_array);
sort_item_array (item_array);
printf("\n\nHUFFMAN> This is the sorted item array:\n");
print_item_array (item_array);
create_huffman_code(item_array);
printf("\n\nHUFFMAN> This is the Huffman coding of the
characters:\n");
print_item_array(item_array);
printf("\n> Coding the file");
convert_long_to_short(item_array, &file_header);
code_and_write_output_file(item_array,
input_file_name,
output_file_name,
&file_header);
} /* ends else compress input file to output file */
} /* ends main */
/*
read_input_file_and_create_histogram(...
Read the input file. Count up the occurances of each
character and create a histogram.
*/
read_input_file_and_create_histogram(input_file_name, item_array)
char input_file_name[];
struct item_struct item_array[];
{
char buffer[1000];
int bytes_read,
i,
in_file_desc,
j;
clear_item_array (item_array);
in_file_desc = my_open(input_file_name);
printf("\n> in file desc = %d", in_file_desc);
bytes_read = 1000;
while(bytes_read == 1000){
bytes_read = my_read(in_file_desc, buffer, 1000);
for(i=0; i<bytes_read; i++) {
j = buffer[1];
item_array[j].count = item_array[j].count + 1;
} /* ends loop over i */
} /* ends while bytes_read == 1000 */
close (in_file_desc);
} /* ends read_input_file_and_create_histogram */
/*
clear_item_array(...
This function initializes the item_array.
*/
clear_item_array(item_array)
struct item_struct item_array[];
{
int i,j, k;
for(i=0; i<LENGTH; i++)(
item_array[i].indicator = 'E';
item_array[i].character = i;
item_array[i].count = 0;
for(k=0; k<LLENGTH; k++)
item_array[i].includes[k] = 256;
for(j=0; j<CODE_LENGTH; j++)
item_array[i].coded[j] = OTHER;
} /* ends loop over i */
} /* ends clear_item_array */
/*
print_item_array (item_array)
This function is for debugging. It prints
to the screen the item_array.
*/
print_item_array (item_array)
struct item_struct item_array[];
{
char response[5];
int i,
j,
k,
max_i,
printed;
float ratio;
long max;
printed = 0;
max = 0;
printf("\n>");
printed++;
for(i=0; i<LENGTH; i++){
if(item_array[i].count > max){
max = item_array[i].count;
max_i = i;
} /* ends if count > max */
} /* ends loop over i */
ratio = 30.0/(float) (item_array[max_i].count);
for(i=0; i<LENGTH; i++){
if(item_array[i].count != 0){
printed++;
if((printed%22) == 0){
printf("/n> Hit return to continue-");
read_string(response);
} /* ends if printed 20 lines */
printf("\n> [%3d]=%3d=%c=%4d=", i, item_array[i].character,
item_array[i].indicator,
item_array[i].count);
for(k=0; k<CODE_LENGTH; k++)
printf ("%c", item_array[i].coded[k]);
for(j=0; j<(ratio*item_array[i].count); j++){
printf("*");
} /* ends loop over j */
} /* ends if count != 0 */
} /* ends loop over i */
} /* ends print_item_array */
/*
convert_long_to_short (...
This function converts the long item_array into
a shorter file header.
*/
convert_long_ to_ short(item_array, file_header)
struct item_struct item_array[];
struct header_struct *file_header;
{
int i, j, k;
for(i=0; i<LENGTH; i++){
file_header->items[i].character = item_array[i].character;
for(j=0; J<CODE_LENGTH; j++)
file_header->items[i].coded[j] = item_array[i].coded[j];
} /* ends loop over i */
} /* ends convert_long_to_short */
/*
convert_short_to_long (...
This function converts the short file header into
a the longer item_array for use in the program.
*/
convert_short_to_long (item_array, file_header)
struct item_struct item_array[];
struct header_struct *file_header;
{
int i, j, k;
for(i=0; i<LENGTH; i++){
item_array[i].character = file_header->items[i].character;
for(j=0; J<CODE_LENGTH; j++)
item_array[i].coded[j] = file_header->items[i].coded[j];
} /* ends loop over i */
} /* ends convert_short_to_long */
/* End of File */