ip: add iec formatted option and cleanup code

Add a new -iec option in addition to -human.
Cleanup code so the formatting of numbers is done in one function,
not 2 ways and 2 sizes.

include/utils.h

@@ -12,6 +12,7 @@
 
 extern int preferred_family;
 extern int human_readable;
+extern int use_iec;
 extern int show_stats;
 extern int show_details;
 extern int show_raw;

ip/ip.c

@@ -25,6 +25,7 @@
 
 int preferred_family = AF_UNSPEC;
 int human_readable = 0;
+int use_iec = 0;
 int show_stats = 0;
 int show_details = 0;
 int resolve_hosts = 0;
@@ -48,7 +49,7 @@ static void usage(void)
 "                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm |\n"
 "                   netns | l2tp | tcp_metrics | token | netconf }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n"
-"                    -h[uman-readable] |\n"
+"                    -h[uman-readable] | -iec |\n"
 "                    -f[amily] { inet | inet6 | ipx | dnet | bridge | link } |\n"
 "                    -4 | -6 | -I | -D | -B | -0 |\n"
 "                    -l[oops] { maximum-addr-flush-attempts } |\n"
@@ -217,6 +218,8 @@ int main(int argc, char **argv)
 		} else if (matches(opt, "-human") == 0 ||
 			   matches(opt, "-human-readable") == 0) {
 			++human_readable;
+		} else if (matches(opt, "-iec") == 0) {
+			++use_iec;
 		} else if (matches(opt, "-stats") == 0 ||
 			   matches(opt, "-statistics") == 0) {
 			++show_stats;

man/man8/ip-link.8.in

@@ -661,11 +661,23 @@ specifies what group of devices to show.
 .B up
 only display running interfaces.
 
-.SH "NOTES"
-Human readable values are calculated with SI prefixes, so with a decimal
-base, not binary. (This is unlike
-.BR ifconfig (8)
-, with uses binary prefix.) 1,000 bytes are 1 kB, 1,000 kB are 1 MB, ...
+The show command has additional formatting options:
+
+.TP
+.BR "\-s" , " \-stats", " \-statistics"
+output more statistics about packet usage.
+
+.TP
+.BR "\-d", " \-details"
+output more detailed information.
+
+.TP
+.BR "\-h", " \-human", " \-human-readble"
+output statistics with human readable values number followed by suffix
+
+.TP
+.BR "\-iec"
+print human readable rates in IEC units (ie. 1K = 1024).
 
 .SH "EXAMPLES"
 .PP