color: use "light" colors for dark background

COLORFGBG environment variable is used to detect dark background.

Idea and a bit of code is borrowed from Vim, thanks.

Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
This commit is contained in:
Petr Vorel 2017-03-01 21:52:33 +01:00 committed by Stephen Hemminger
parent d896797c7b
commit 54eab4c79a
2 changed files with 46 additions and 1 deletions

View File

@ -12,6 +12,7 @@ enum color_attr {
};
void enable_color(void);
void set_color_palette(void);
int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...);
enum color_attr ifa_family_color(__u8 ifa_family);
enum color_attr oper_state_color(__u8 state);

View File

@ -1,5 +1,7 @@
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <linux/if.h>
@ -14,6 +16,13 @@ enum color {
C_MAGENTA,
C_CYAN,
C_WHITE,
C_BOLD_RED,
C_BOLD_GREEN,
C_BOLD_YELLOW,
C_BOLD_BLUE,
C_BOLD_MAGENTA,
C_BOLD_CYAN,
C_BOLD_WHITE,
C_CLEAR
};
@ -25,25 +34,59 @@ static const char * const color_codes[] = {
"\e[35m",
"\e[36m",
"\e[37m",
"\e[1;31m",
"\e[1;32m",
"\e[1;33m",
"\e[1;34m",
"\e[1;35m",
"\e[1;36m",
"\e[1;37m",
"\e[0m",
NULL,
};
static enum color attr_colors[] = {
/* light background */
C_CYAN,
C_YELLOW,
C_MAGENTA,
C_BLUE,
C_GREEN,
C_RED,
C_CLEAR,
/* dark background */
C_BOLD_CYAN,
C_BOLD_YELLOW,
C_BOLD_MAGENTA,
C_BOLD_BLUE,
C_BOLD_GREEN,
C_BOLD_RED,
C_CLEAR
};
static int is_dark_bg;
static int color_is_enabled;
void enable_color(void)
{
color_is_enabled = 1;
set_color_palette();
}
void set_color_palette(void)
{
char *p = getenv("COLORFGBG");
/*
* COLORFGBG environment variable usually contains either two or three
* values separated by semicolons; we want the last value in either case.
* If this value is 0-6 or 8, background is dark.
*/
if (p && (p = strrchr(p, ';')) != NULL
&& ((p[1] >= '0' && p[1] <= '6') || p[1] == '8')
&& p[2] == '\0')
is_dark_bg = 1;
}
int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...)
@ -58,7 +101,8 @@ int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...)
goto end;
}
ret += fprintf(fp, "%s", color_codes[attr_colors[attr]]);
ret += fprintf(fp, "%s",
color_codes[attr_colors[is_dark_bg ? attr + 7 : attr]]);
ret += vfprintf(fp, fmt, args);
ret += fprintf(fp, "%s", color_codes[C_CLEAR]);