utils.c

#include "utils.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

void print_help(char* target)
{
    printf("Hex Editor\n");
    printf("Usage: %s [-m2h] [input]\n\n", target);

    printf("Arguments:\n");
    printf("================================================\n");
    printf(" -h   | --help              : Print this message\n");
    printf(" -b2h | --binary_to_hex     : Mode to dump hex\n");
    printf(" -h2b | --hex_to_binary     : Mode to save binary\n");
}

void error_infile(char* target)
{
	fprintf(stderr, "Usage: %s [-m2h] [input]\n", target);
}

void error_infile_open()
{
	fprintf(stderr, "Couldn't open the input file\n");
}

void print_pretty(char offset, int act_read_bytes, uint8_t* buffer, FILE* out_file)
{
    // prints read bytes and hex in intuitive format
    fprintf(out_file, "%016lld ", offset);

    for (int i = 0; i < LEN_LINE; i++)
    {
	if (i < act_read_bytes)
	{
	    fprintf(out_file, " %02X", buffer[i]);
	}
	else{
	    fprintf(out_file, "   ");
	}
    }

    fprintf(out_file, " |");
    for (int i = 0; i < act_read_bytes; i++)
    {
	if (buffer[i] > 31 && buffer[i] < 127) 
	    fprintf(out_file, "%c", buffer[i]);
	else fprintf(out_file, ".");
    }

    fprintf(out_file, "|\n");
};

void bin2hex(FILE* in_file, FILE* out_file)
{
    // allocate approriate memory for buffer 
    uint8_t* buffer = (uint8_t*)malloc(LEN_LINE);

    int offset = 0x0000000000000001;
    while(!feof(in_file))
    {
	int read_bytes = LEN_LINE;

	int act_read_bytes = fread(buffer, sizeof(uint8_t), read_bytes, in_file);
	if (act_read_bytes > 0)
	{
	    print_pretty(offset, act_read_bytes, buffer, out_file);
	    offset += act_read_bytes;
	}
	else break;
    }

    free(buffer);
}

void hex2bin(FILE* in_file, FILE* out_file)
{
    int count = 0;
    char curr_char, curr_char_value, curr_byte=0;

    fseek(in_file, OFFSET, SEEK_CUR);
    while (!feof(in_file))
    {
	int n = fread(&curr_char, sizeof(char), 1, in_file);
	if (n == 0) break;

	if (curr_char == '\n')
	{
	    fseek(in_file, OFFSET, SEEK_CUR);
	}
	else if (curr_char == '|')
	{
	    fseek(in_file, 16+1, SEEK_CUR);
	    continue;
	}
	else if (curr_char >= '0' && curr_char <= '9')
	    curr_char_value = curr_char - '0';
	else if (curr_char >= 'A' && curr_char <= 'F')
	    curr_char_value = curr_char - 'A' + 0xa;
	else continue;

	curr_byte = (curr_byte << 2) + curr_char_value;

	if (count)
	    fprintf(out_file, "%c", curr_byte);

	count = count+1;
	count = count%2;
    }
}