path: root/lib/colors.c

/*
 * Copyright (C) 2012 Ondrej Oprala <ooprala@redhat.com>
 *
 * This file may be distributed under the terms of the
 * GNU Lesser General Public License.
 */
#include <c.h>
#include <assert.h>

#include "colors.h"

static int ul_color_term_ok;

int colors_init(int mode)
{
	switch (mode) {
	case UL_COLORMODE_AUTO:
		ul_color_term_ok = isatty(STDOUT_FILENO);
		break;
	case UL_COLORMODE_ALWAYS:
		ul_color_term_ok = 1;
		break;
	case UL_COLORMODE_NEVER:
	default:
		ul_color_term_ok = 0;
	}
	return ul_color_term_ok;
}

void color_enable(const char *color_scheme)
{
	if (ul_color_term_ok && color_scheme)
		fputs(color_scheme, stdout);
}

void color_disable(void)
{
	if (ul_color_term_ok)
		fputs(UL_COLOR_RESET, stdout);
}

int colormode_from_string(const char *str)
{
	size_t i;
	static const char *modes[] = {
		[UL_COLORMODE_AUTO]   = "auto",
		[UL_COLORMODE_NEVER]  = "never",
		[UL_COLORMODE_ALWAYS] = "always"
	};

	if (!str || !*str)
		return -EINVAL;

	assert(ARRAY_SIZE(modes) == __UL_NCOLORMODES);

	for (i = 0; i < ARRAY_SIZE(modes); i++) {
		if (strcasecmp(str, modes[i]) == 0)
			return i;
	}

	return -EINVAL;
}

int colormode_or_err(const char *str, const char *errmsg)
{
	const char *p = str && *str == '=' ? str + 1 : str;
	int colormode;

	colormode = colormode_from_string(p);
	if (colormode < 0)
		errx(EXIT_FAILURE, "%s: '%s'", errmsg, p);

	return colormode;
}


#ifdef TEST_PROGRAM
# include <getopt.h>
int main(int argc, char *argv[])
{
	static const struct option longopts[] = {
		{ "colors", optional_argument, 0, 'c' },
		{ NULL, 0, 0, 0 }
	};
	int c, mode = UL_COLORMODE_NEVER;	/* default */

	while ((c = getopt_long(argc, argv, "c::", longopts, NULL)) != -1) {
		switch (c) {
		case 'c':
			mode = UL_COLORMODE_AUTO;
			if (optarg)
				mode = colormode_or_err(optarg, "unsupported color mode");
			break;
		}
	}

	colors_init(mode);
	color_enable(UL_COLOR_RED);
	printf("Hello World!");
	color_disable();
	return EXIT_SUCCESS;
}
#endif