A command line utility to convert a number of binary, octal, decimal or hexadecimal to the other three

makefile

files = typeconvert.c typeconvert.h

typeconvert: $(files)
	cc -o typeconvert $(files)

.PHONY: clean
clean:
	rm typeconvert

typeconvert.c

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

#include "typeconvert.h"

// https://linux.die.net/man/3/getopt


void print_help(int error)
{
    if (error)
        printf("There was an error parsing the flags!\n\n");

    printf("typeconvert: A useless-but-slightly-useful utility to convert one "
        "of binary, octal, decimal or hexadecimal to the other three\n\n");
    printf("Usage: typeconvert [options] input\n");

    printf("Options:\n");
    printf("  --bin <binary_number>\t\tShow oct, dec and hex of a binary "
                                                                    "number\n");
    printf("  --oct <octal_number>\t\tShow bin, dec and hex of an octal "
                                                                    "number\n");
    printf("  --dec <decimal_number>\tShow bin, oct and hex of a decimal "
                                                                    "number\n");
    printf("  --hex <hexadecimal_number>\tShow bin, oct and dec of a "
                                                        "hexadecimal number\n");
    printf("  --help \t\t\tShow this help message\n\n");

    printf("Examples:\n");
    printf("  typeconvert --bin 010100110\n");
    printf("  typeconvert --oct 14270\n");
    printf("  typeconvert --dec 9011\n");
    printf("  typeconvert --hex 0x1234a\n");
    printf("  typeconvert --hex 0x1234A\n");
    printf("  typeconvert --hex 1234a\n");
    printf("  typeconvert --hex 1234A\n");
    printf("  typeconvert --bin 0110 --oct 71 --dec 19 --hex 0xAf01\n\n");

    printf("https://gist.github.com/IceCereal/11016076686ae6e5a544d058518b1871"
                                                                          "\n");
    return;
}

int bin2dec(char *input)
{
    int value = 0;
    int input_length = strlen(input) - 1;

    for (int i = input_length; i >= 0; --i){
        if (input[i] == '0')
            continue;
        else if (input[i] == '1')
            value += 1 << input_length - i;
        else
            assert(0 && "input contained a character other than 0 or 1");
    }

    return value;
}

void dec2bin(int input, char *output)
{
    int output_length = strlen(output);
    int index = 0, first_1_index = -1;

    while (index != output_length) {
        if (input & 1 << (output_length - index - 1))
            output[index] = '1';
        else
            output[index] = '0';
        ++index;
    }
}

int main(int argc, char *argv[])
{
    static struct option long_options[] = {
        { "bin", required_argument, 0, BIN },
        { "oct", required_argument, 0, OCT },
        { "dec", required_argument, 0, DEC },
        { "hex", required_argument, 0, HEX },
        { "help"   , no_argument      , 0, HELP },
        { 0        , 0                , 0, 0 }
    };

    int first_input = 1;

    while (1){
        int c = getopt_long(argc, argv, "", long_options, NULL);
        if (c == -1)
            break;

        if (first_input)
            first_input = 0;
        else
            printf("===========================================\n");

        int decimal_value;
        char output[sizeof(int) * 8];
        memset(output, '0', sizeof(int) * 8);

        switch (c){
            case BIN:
                decimal_value = bin2dec(optarg);
                dec2bin(decimal_value, output);

                printf("Binary: ");
                for (int i = 0; i < sizeof(int); ++i)
                    printf("%.8s ", output + i*8);
                printf("\n");
                printf("Octal: %o \n", decimal_value);
                printf("Decimal: %d \n", decimal_value);
                printf("Hexadecimal: 0x%X \n", decimal_value);

                break;

            case OCT:
                sscanf(optarg, "%o", &decimal_value);

                dec2bin(decimal_value, output);

                printf("Binary: ");
                for (int i = 0; i < sizeof(int); ++i)
                    printf("%.8s ", output + i*8);
                printf("\n");

                printf("Octal: %o \n", decimal_value);
                printf("Decimal: %d \n", decimal_value);
                printf("Hexadecimal: 0x%X \n", decimal_value);
                break;

            case DEC:
                sscanf(optarg, "%d", &decimal_value);

                dec2bin(decimal_value, output);

                printf("Binary: ");
                for (int i = 0; i < sizeof(int); ++i)
                    printf("%.8s ", output + i*8);
                printf("\n");

                printf("Octal: %o \n", decimal_value);
                printf("Decimal: %d \n", decimal_value);
                printf("Hexadecimal: 0x%X \n", decimal_value);
                break;

            case HEX:
                sscanf(optarg, "%x", &decimal_value);

                dec2bin(decimal_value, output);

                printf("Binary: ");
                for (int i = 0; i < sizeof(int); ++i)
                    printf("%.8s ", output + i*8);
                printf("\n");

                printf("Octal: %o \n", decimal_value);
                printf("Decimal: %d \n", decimal_value);
                printf("Hexadecimal: 0x%X \n", decimal_value);
                break;

            case HELP:
                print_help(0);
                break;

            default:
                print_help(1);
                break;
        }

    }

   return 0;
}

typeconvert.h

#ifndef H_TYPECONVERT_H
#define H_TYPECONVERT_H

#define BIN   2
#define OCT   8
#define DEC  10
#define HEX  16
#define HELP 20

void print_help(int);

int bin2dec(char *input);
int oct2dec(char *input);
int hex2dec(char *input);

void dec2bin(int input, char *output);

#endif

Typeconvert.md

Use Typeconvert_V2.

Typeconvert

Why can't I find a single and simple command line utility to convert a number in one base to another base.

Yeah, it's simple to make your own program or launch a python shell to get it to print a number out in a different base or go to rapidtables.com, but why can't I find a single command line utility to do this for me. Either way, enough ranting. Here's some code.

This isn't important enough to warrant a repository and that's why it's a gist of 4 files.

Precautions:

• This assumes little endian representation.
• This has been only programmed for int (signed) because I didn't have the need to make it long so, ymmv on your system. It will not work for numbers that go out of the range of int.
• If you want to modify it in anyway, go right ahead. This is "licensed" with the do-whatever-the-heck-you-want-with-it-but-im-not-responsible-for-anything license

Compile

Run make and then move the object (typeconvert) to your /path/to/bin folder to use it as a system wide utility.

Examples

typeconvert --help

typeconvert --bin 010100110

typeconvert --oct 14270

typeconvert --dec 9011

typeconvert --hex 0x1234a

typeconvert --hex 0x1234A

typeconvert --hex 1234a

typeconvert --hex 1234A

typeconvert --bin 0110 --oct 71 --dec 19 --hex 0xAf01