xcd-rgb

xcd.c (3605B)

// SPDX-FileCopyrightText: 2017-2022 Haelwenn (lanodan) Monnier <contact+xcd-rgb@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#define _XOPEN_SOURCE 700
#include <ctype.h>  /* isprint() */
#include <errno.h>  /* errno */
#include <math.h>   /* sin() */
#include <stdint.h> /* uint8_t */
#include <stdio.h>  /* printf(), fread(), fopen(), fclose() */
#include <string.h> /* memset(), strerror() */
#ifndef M_PI
#define 3.14159265358979323846
#endif
#ifndef ARG0_XCD_RGB
const char *argv0 = "xcd-rgb";
#else
const char *argv0 = "xcd";
#endif
struct rgb
{
	int r, g, b;
};
static struct rgb
rgb_char(uint8_t i)
{
	double freq = 0.018;
	if(i == 0) return (struct rgb){64, 64, 64};
	struct rgb color;
	color.r = sin(freq * i + 0 * M_PI / 3) * 127 + 128;
	color.g = sin(freq * i + 2 * M_PI / 3) * 127 + 128;
	color.b = sin(freq * i + 4 * M_PI / 3) * 127 + 128;
	return color;
}
static int
print_hex_rgb(uint8_t c)
{
	struct rgb color = rgb_char(c);
	if(printf("\033[38;2;%d;%d;%dm%02hhx ", color.r, color.g, color.b, c) <= 0) return 1;
	return 0;
}
static int
print_xcd_reset()
{
	if(printf("\033[0m\033[48;2;0;0;0m") <= 0) return 1;
	return 0;
}
static int
print_plain_rgb(char *line, size_t len)
{
	if(print_xcd_reset() != 0) return 1;
	if(printf(" >") <= 0) return 1;
	for(size_t i = 0; i < len; i++)
	{
		struct rgb color = rgb_char(line[i]);
		if(printf(
		       "\033[38;2;%d;%d;%dm%c", color.r, color.g, color.b, isprint(line[i]) ? line[i] : '.') <=
		   0)
			return 1;
	}
	if(print_xcd_reset() != 0) return 1;
	if(printf("<") <= 0) return 1;
	return 0;
}
#define WIDTH 16
static int
concat(FILE *stream)
{
	long unsigned int bytes = 0;
	errno = 0;
	if(print_xcd_reset() != 0) goto werr;
	struct rgb pos_rgb = rgb_char(bytes);
	if(printf("\033[38;2;%d;%d;%dm0x%06lx ", pos_rgb.r, pos_rgb.g, pos_rgb.b, bytes) < 0) goto werr;
	size_t cols      = 0;
	char line[WIDTH] = "";
	char c;
	while(fread(&c, 1, 1, stream) > 0)
	{
		if(cols >= WIDTH)
		{
			print_plain_rgb(line, cols);
			memset(&line, 0, WIDTH);
			pos_rgb = rgb_char(bytes);
			if(printf("\n\033[38;2;%d;%d;%dm0x%06lx ", pos_rgb.r, pos_rgb.g, pos_rgb.b, bytes) < 0)
				goto werr;
			cols = 0;
		}
		if(print_hex_rgb(c) != 0) goto werr;
		line[cols] = c;
		cols++;
		bytes++;
	}
	// Fill the rest of the hex space with spaces
	for(; cols < WIDTH; cols++)
		if(printf("   ") <= 0) goto werr;
	if(print_plain_rgb(line, cols) != 0) goto werr;
	pos_rgb = rgb_char(bytes);
	if(printf("\n\033[38;2;%d;%d;%dm0x%06lx\n", pos_rgb.r, pos_rgb.g, pos_rgb.b, bytes) <= 0)
		goto werr;
	if(print_xcd_reset() != 0) goto werr;
	return 0;
werr:
	fprintf(stderr, "\n\033[0m%s: error: Failed writing to stdout: %s\n", argv0, strerror(errno));
	return 1;
}
int
main(int argc, char *argv[])
{
	int err = 0;
	if(argc <= 1)
	{
		err = concat(stdin);
		printf("\033[0m");
		return err;
	}
	for(int argi = 1; (err == 0) && (argi < argc); argi++)
	{
		if(strncmp(argv[argi], "-", 2) == 0)
		{
			if(concat(stdin) != 0)
			{
				err = 1;
				break;
			}
			continue;
		}
		FILE *file = fopen(argv[argi], "rb");
		if(!file)
		{
			fprintf(stderr,
			        "\n\033[0m%s: error: Failed opening file ‘%s’: %s\n",
			        argv0,
			        argv[argi],
			        strerror(errno));
			err = 1;
			break;
		}
		err += concat(file);
		if(fclose(file) != 0)
		{
			fprintf(stderr,
			        "\n\033[0m%s: error: Failed closing file ‘%s’: %s\n",
			        argv0,
			        argv[argi],
			        strerror(errno));
			err = 1;
			break;
		}
	}
	printf("\033[0m");
	return err;
}