ip: Add color output option

It is hard to quickly find what you are looking for in the output of the
ip command. Color helps.

This patch adds a '-c' flag to highlight these with individual colors:
  - interface name
  - ip address
  - mac address
  - up/down state
Signed-off-by: Mathias Nyman <m.nyman@iki.fi>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>

include/color.h

+#ifndef __COLOR_H__
+#define __COLOR_H__ 1
+
+enum color_attr {
+	COLOR_IFNAME,
+	COLOR_MAC,
+	COLOR_INET,
+	COLOR_INET6,
+	COLOR_OPERSTATE_UP,
+	COLOR_OPERSTATE_DOWN
+};
+
+void enable_color(void);
+int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...);
+
+#endif

ip/ip.c

@@ -23,6 +23,7 @@
 #include "utils.h"
 #include "ip_common.h"
 #include "namespace.h"
+#include "color.h"
 
 int preferred_family = AF_UNSPEC;
 int human_readable = 0;
@@ -56,7 +57,7 @@ static void usage(void)
 "                    -4 | -6 | -I | -D | -B | -0 |\n"
 "                    -l[oops] { maximum-addr-flush-attempts } |\n"
 "                    -o[neline] | -t[imestamp] | -ts[hort] | -b[atch] [filename] |\n"
-"                    -rc[vbuf] [size] | -n[etns] name | -a[ll] }\n");
+"                    -rc[vbuf] [size] | -n[etns] name | -a[ll] | -c[olor]}\n");
 	exit(-1);
 }
 
@@ -257,6 +258,8 @@ int main(int argc, char **argv)
 				exit(-1);
 			}
 			rcvbuf = size;
+		} else if (matches(opt, "-color") == 0) {
+			enable_color();
 		} else if (matches(opt, "-help") == 0) {
 			usage();
 		} else if (matches(opt, "-netns") == 0) {

ip/ipaddress.c

@@ -34,6 +34,7 @@
 #include "utils.h"
 #include "ll_map.h"
 #include "ip_common.h"
+#include "color.h"
 
 enum {
 	IPADD_LIST,
@@ -136,8 +137,15 @@ static void print_operstate(FILE *f, __u8 state)
 {
 	if (state >= sizeof(oper_states)/sizeof(oper_states[0]))
 		fprintf(f, "state %#x ", state);
+	else {
+		fprintf(f, "state ");
+		if (strcmp(oper_states[state], "UP") == 0)
+			color_fprintf(f, COLOR_OPERSTATE_UP, "%s ", oper_states[state]);
+		else if (strcmp(oper_states[state], "DOWN") == 0)
+			color_fprintf(f, COLOR_OPERSTATE_DOWN, "%s ", oper_states[state]);
 		else
-		fprintf(f, "state %s ", oper_states[state]);
+			fprintf(f, "%s ", oper_states[state]);
+	}
 }
 
 int get_operstate(const char *name)
@@ -606,7 +614,8 @@ int print_linkinfo(const struct sockaddr_nl *who,
 	if (n->nlmsg_type == RTM_DELLINK)
 		fprintf(fp, "Deleted ");
 
-	fprintf(fp, "%d: %s", ifi->ifi_index,
+	fprintf(fp, "%d: ", ifi->ifi_index);
+	color_fprintf(fp, COLOR_IFNAME, "%s",
 		tb[IFLA_IFNAME] ? rta_getattr_str(tb[IFLA_IFNAME]) : "<nil>");
 
 	if (tb[IFLA_LINK]) {
@@ -666,7 +675,8 @@ int print_linkinfo(const struct sockaddr_nl *who,
 		fprintf(fp, "    link/%s ", ll_type_n2a(ifi->ifi_type, b1, sizeof(b1)));
 
 		if (tb[IFLA_ADDRESS]) {
-			fprintf(fp, "%s", ll_addr_n2a(RTA_DATA(tb[IFLA_ADDRESS]),
+			color_fprintf(fp, COLOR_MAC, "%s",
+					ll_addr_n2a(RTA_DATA(tb[IFLA_ADDRESS]),
 						RTA_PAYLOAD(tb[IFLA_ADDRESS]),
 						ifi->ifi_type,
 						b1, sizeof(b1)));
@@ -849,6 +859,17 @@ int print_addrinfo(const struct sockaddr_nl *who, struct nlmsghdr *n,
 		fprintf(fp, "    family %d ", ifa->ifa_family);
 
 	if (rta_tb[IFA_LOCAL]) {
+		if (ifa->ifa_family == AF_INET)
+			color_fprintf(fp, COLOR_INET, "%s", format_host(ifa->ifa_family,
+						RTA_PAYLOAD(rta_tb[IFA_LOCAL]),
+						RTA_DATA(rta_tb[IFA_LOCAL]),
+						abuf, sizeof(abuf)));
+		else if (ifa->ifa_family == AF_INET6)
+			color_fprintf(fp, COLOR_INET6, "%s", format_host(ifa->ifa_family,
+						RTA_PAYLOAD(rta_tb[IFA_LOCAL]),
+						RTA_DATA(rta_tb[IFA_LOCAL]),
+						abuf, sizeof(abuf)));
+		else
 			fprintf(fp, "%s", format_host(ifa->ifa_family,
 						RTA_PAYLOAD(rta_tb[IFA_LOCAL]),
 						RTA_DATA(rta_tb[IFA_LOCAL]),

lib/Makefile

@@ -7,7 +7,7 @@ endif
 CFLAGS += -fPIC
 
 UTILOBJ=utils.o rt_names.o ll_types.o ll_proto.o ll_addr.o inet_proto.o namespace.o \
-	names.o
+	names.o color.o
 
 NLOBJ=libgenl.o ll_map.o libnetlink.o
 

lib/color.c

+#include <stdio.h>
+#include <stdarg.h>
+
+#include "color.h"
+
+enum color {
+	C_RED,
+	C_GREEN,
+	C_YELLOW,
+	C_BLUE,
+	C_MAGENTA,
+	C_CYAN,
+	C_WHITE,
+	C_CLEAR
+};
+
+static const char * const color_codes[] = {
+	"\e[31m",
+	"\e[32m",
+	"\e[33m",
+	"\e[34m",
+	"\e[35m",
+	"\e[36m",
+	"\e[37m",
+	"\e[0m",
+	NULL,
+};
+
+static enum color attr_colors[] = {
+	C_CYAN,
+	C_YELLOW,
+	C_MAGENTA,
+	C_BLUE,
+	C_GREEN,
+	C_RED
+};
+
+static int color_is_enabled;
+
+void enable_color(void)
+{
+	color_is_enabled = 1;
+}
+
+int color_fprintf(FILE *fp, enum color_attr attr, const char *fmt, ...)
+{
+	int ret = 0;
+	va_list args;
+
+	va_start(args, fmt);
+
+	if (!color_is_enabled) {
+		ret = vfprintf(fp, fmt, args);
+		goto end;
+	}
+
+	ret += fprintf(fp, "%s", color_codes[attr_colors[attr]]);
+	ret += vfprintf(fp, fmt, args);
+	ret += fprintf(fp, "%s", color_codes[C_CLEAR]);
+
+end:
+	va_end(args);
+	return ret;
+}

man/man8/ip.8

@@ -33,7 +33,8 @@ ip \- show / manipulate routing, devices, policy routing and tunnels
 .BR inet " | " inet6 " | " ipx " | " dnet " | " link " } | "
 \fB\-o\fR[\fIneline\fR] |
 \fB\-n\fR[\fIetns\fR] name |
-\fB\-a\fR[\fIll\fR] }
+\fB\-a\fR[\fIll\fR] |
+\fB\-c\fR[\fIolor\fR] }
 
 
 .SH OPTIONS
@@ -165,6 +166,10 @@ to
 .BR "\-a" , " \-all"
 executes specified command over all objects, it depends if command supports this option.
 
+.TP
+.BR "\-c" , " -color"
+Use color output.
+
 .SH IP - COMMAND SYNTAX
 
 .SS