text: #include <linux/kernel.h>
  #include "cache.h"
  #include "color.h"
  
  int perf_use_color_default = -1;
  
  static int parse_color(const char *name, int len)
  {
  	static const char * const color_names[] = {
  		"normal", "black", "red", "green", "yellow",
  		"blue", "magenta", "cyan", "white"
  	};
  	char *end;
  	int i;
  
  	for (i = 0; i < (int)ARRAY_SIZE(color_names); i++) {
  		const char *str = color_names[i];
  		if (!strncasecmp(name, str, len) && !str[len])
  			return i - 1;
  	}
  	i = strtol(name, &end, 10);
  	if (end - name == len && i >= -1 && i <= 255)
  		return i;
  	return -2;
  }
  
  static int parse_attr(const char *name, int len)
  {
  	static const int attr_values[] = { 1, 2, 4, 5, 7 };
  	static const char * const attr_names[] = {
  		"bold", "dim", "ul", "blink", "reverse"
  	};
  	unsigned int i;
  
  	for (i = 0; i < ARRAY_SIZE(attr_names); i++) {
  		const char *str = attr_names[i];
  		if (!strncasecmp(name, str, len) && !str[len])
  			return attr_values[i];
  	}
  	return -1;
  }
  
  void color_parse(const char *value, const char *var, char *dst)
  {
  	color_parse_mem(value, strlen(value), var, dst);
  }
  
  void color_parse_mem(const char *value, int value_len, const char *var,
  		char *dst)
  {
  	const char *ptr = value;
  	int len = value_len;
  	int attr = -1;
  	int fg = -2;
  	int bg = -2;
  
  	if (!strncasecmp(value, "reset", len)) {
  		strcpy(dst, PERF_COLOR_RESET);
  		return;
  	}
  
  	/* [fg [bg]] [attr] */
  	while (len > 0) {
  		const char *word = ptr;
  		int val, wordlen = 0;
  
  		while (len > 0 && !isspace(word[wordlen])) {
  			wordlen++;
  			len--;
  		}
  
  		ptr = word + wordlen;
  		while (len > 0 && isspace(*ptr)) {
  			ptr++;
  			len--;
  		}
  
  		val = parse_color(word, wordlen);
  		if (val >= -1) {
  			if (fg == -2) {
  				fg = val;
  				continue;
  			}
  			if (bg == -2) {
  				bg = val;
  				continue;
  			}
  			goto bad;
  		}
  		val = parse_attr(word, wordlen);
  		if (val < 0 || attr != -1)
  			goto bad;
  		attr = val;
  	}
  
  	if (attr >= 0 || fg >= 0 || bg >= 0) {
  		int sep = 0;
  
  		*dst++ = '\033';
  		*dst++ = '[';
  		if (attr >= 0) {
  			*dst++ = '0' + attr;
  			sep++;
  		}
  		if (fg >= 0) {
  			if (sep++)
  				*dst++ = ';';
  			if (fg < 8) {
  				*dst++ = '3';
  				*dst++ = '0' + fg;
  			} else {
  				dst += sprintf(dst, "38;5;%d", fg);
  			}
  		}
  		if (bg >= 0) {
  			if (sep++)
  				*dst++ = ';';
  			if (bg < 8) {
  				*dst++ = '4';
  				*dst++ = '0' + bg;
  			} else {
  				dst += sprintf(dst, "48;5;%d", bg);
  			}
  		}
  		*dst++ = 'm';
  	}
  	*dst = 0;
  	return;
  bad:
  	die("bad color value '%.*s' for variable '%s'", value_len, value, var);
  }
  
  int perf_config_colorbool(const char *var, const char *value, int stdout_is_tty)
  {
  	if (value) {
  		if (!strcasecmp(value, "never"))
  			return 0;
  		if (!strcasecmp(value, "always"))
  			return 1;
  		if (!strcasecmp(value, "auto"))
  			goto auto_color;
  	}
  
  	/* Missing or explicit false to turn off colorization */
  	if (!perf_config_bool(var, value))
  		return 0;
  
  	/* any normal truth value defaults to 'auto' */
   auto_color:
  	if (stdout_is_tty < 0)
  		stdout_is_tty = isatty(1);
  	if (stdout_is_tty || (pager_in_use() && pager_use_color)) {
  		char *term = getenv("TERM");
  		if (term && strcmp(term, "dumb"))
  			return 1;
  	}
  	return 0;
  }
  
  int perf_color_default_config(const char *var, const char *value, void *cb)
  {
  	if (!strcmp(var, "color.ui")) {
  		perf_use_color_default = perf_config_colorbool(var, value, -1);
  		return 0;
  	}
  
  	return perf_default_config(var, value, cb);
  }
  
  static int __color_vsnprintf(char *bf, size_t size, const char *color,
  			     const char *fmt, va_list args, const char *trail)
  {
  	int r = 0;
  
  	/*
  	 * Auto-detect:
  	 */
  	if (perf_use_color_default < 0) {
  		if (isatty(1) || pager_in_use())
  			perf_use_color_default = 1;
  		else
  			perf_use_color_default = 0;
  	}
  
  	if (perf_use_color_default && *color)
  		r += scnprintf(bf, size, "%s", color);
  	r += vscnprintf(bf + r, size - r, fmt, args);
  	if (perf_use_color_default && *color)
  		r += scnprintf(bf + r, size - r, "%s", PERF_COLOR_RESET);
  	if (trail)
  		r += scnprintf(bf + r, size - r, "%s", trail);
  	return r;
  }
  
  static int __color_vfprintf(FILE *fp, const char *color, const char *fmt,
  		va_list args, const char *trail)
  {
  	int r = 0;
  
  	/*
  	 * Auto-detect:
  	 */
  	if (perf_use_color_default < 0) {
  		if (isatty(fileno(fp)) || pager_in_use())
  			perf_use_color_default = 1;
  		else
  			perf_use_color_default = 0;
  	}
  
  	if (perf_use_color_default && *color)
  		r += fprintf(fp, "%s", color);
  	r += vfprintf(fp, fmt, args);
  	if (perf_use_color_default && *color)
  		r += fprintf(fp, "%s", PERF_COLOR_RESET);
  	if (trail)
  		r += fprintf(fp, "%s", trail);
  	return r;
  }
  
  int color_vsnprintf(char *bf, size_t size, const char *color,
  		    const char *fmt, va_list args)
  {
  	return __color_vsnprintf(bf, size, color, fmt, args, NULL);
  }
  
  int color_vfprintf(FILE *fp, const char *color, const char *fmt, va_list args)
  {
  	return __color_vfprintf(fp, color, fmt, args, NULL);
  }
  
  int color_snprintf(char *bf, size_t size, const char *color,
  		   const char *fmt, ...)
  {
  	va_list args;
  	int r;
  
  	va_start(args, fmt);
  	r = color_vsnprintf(bf, size, color, fmt, args);
  	va_end(args);
  	return r;
  }
  
  int color_fprintf(FILE *fp, const char *color, const char *fmt, ...)
  {
  	va_list args;
  	int r;
  
  	va_start(args, fmt);
  	r = color_vfprintf(fp, color, fmt, args);
  	va_end(args);
  	return r;
  }
  
  int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...)
  {
  	va_list args;
  	int r;
  	va_start(args, fmt);
  	r = __color_vfprintf(fp, color, fmt, args, "\n");
  	va_end(args);
  	return r;
  }
  
  /*
   * This function splits the buffer by newlines and colors the lines individually.
   *
   * Returns 0 on success.
   */
  int color_fwrite_lines(FILE *fp, const char *color,
  		size_t count, const char *buf)
  {
  	if (!*color)
  		return fwrite(buf, count, 1, fp) != 1;
  
  	while (count) {
  		char *p = memchr(buf, '\n', count);
  
  		if (p != buf && (fputs(color, fp) < 0 ||
  				fwrite(buf, p ? (size_t)(p - buf) : count, 1, fp) != 1 ||
  				fputs(PERF_COLOR_RESET, fp) < 0))
  			return -1;
  		if (!p)
  			return 0;
  		if (fputc('\n', fp) < 0)
  			return -1;
  		count -= p + 1 - buf;
  		buf = p + 1;
  	}
  	return 0;
  }
  
  const char *get_percent_color(double percent)
  {
  	const char *color = PERF_COLOR_NORMAL;
  
  	/*
  	 * We color high-overhead entries in red, mid-overhead
  	 * entries in green - and keep the low overhead places
  	 * normal:
  	 */
  	if (percent >= MIN_RED)
  		color = PERF_COLOR_RED;
  	else {
  		if (percent > MIN_GREEN)
  			color = PERF_COLOR_GREEN;
  	}
  	return color;
  }
  
  int percent_color_fprintf(FILE *fp, const char *fmt, double percent)
  {
  	int r;
  	const char *color;
  
  	color = get_percent_color(percent);
  	r = color_fprintf(fp, color, fmt, percent);
  
  	return r;
  }
  
  int percent_color_snprintf(char *bf, size_t size, const char *fmt, ...)
  {
  	va_list args;
  	double percent;
  	const char *color;
  
  	va_start(args, fmt);
  	percent = va_arg(args, double);
  	va_end(args);
  	color = get_percent_color(percent);
  	return color_snprintf(bf, size, color, fmt, percent);
  }
  