top: use poll instead of select for waiting on one descriptor

smart_ulltoa5: make it more cryptic. -50 bytes.

function                                             old     new   delta
passwd_main                                         1095    1103      +8
getNum                                               557     565      +8
buffer_fill_and_print                                 73      76      +3
udhcpc_main                                         2393    2395      +2
mkfs_minix_main                                     3071    3070      -1
dname_enc                                            377     373      -4
expmeta                                              480     472      -8
smart_ulltoa5                                        334     283     -51
top_main                                             911     815     -96
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/5 up/down: 21/-160)          Total: -139 bytes
   text    data     bss     dec     hex filename
 770872    1063   10788  782723   bf183 busybox_old
 770732    1063   10788  782583   bf0f7 busybox_unstripped

3 files changed, 48 insertions, 38 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 89a1695fa..678c56109 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -27,6 +27,7 @@
 #include <stddef.h>
 #include <string.h>
 /* #include <strings.h> - said to be obsolete */
+#include <sys/poll.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index fa9fc10d6..140c7bb6f 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -284,35 +284,44 @@ void smart_ulltoa5(unsigned long long ul, char buf[5])
 {
 	const char *fmt;
 	char c;
-	unsigned v,idx = 0;
-	ul *= 10;
-	if (ul > 9999*10) { // do not scale if 9999 or less
-		while (ul >= 10000) {
+	unsigned v, u, idx = 0;
+
+	if (ul > 9999) { // do not scale if 9999 or less
+		ul *= 10;
+		do {
 			ul /= 1024;
 			idx++;
-		}
+		} while (ul >= 10000);
 	}
 	v = ul; // ullong divisions are expensive, avoid them
 
 	fmt = " 123456789";
-	if (!idx) {		// 9999 or less: use 1234 format
-		c = buf[0] = " 123456789"[v/10000];
+	u = v / 10;
+	v = v % 10;
+	if (!idx) {
+		// 9999 or less: use "1234" format
+		// u is value/10, v is last digit
+		c = buf[0] = " 123456789"[u/100];
 		if (c != ' ') fmt = "0123456789";
-		c = buf[1] = fmt[v/1000%10];
+		c = buf[1] = fmt[u/10%10];
 		if (c != ' ') fmt = "0123456789";
-		buf[2] = fmt[v/100%10];
-		buf[3] = "0123456789"[v/10%10];
+		buf[2] = fmt[u%10];
+		buf[3] = "0123456789"[v];
 	} else {
-		if (v >= 10*10) {	// scaled value is >=10: use 123M format
-			c = buf[0] = " 123456789"[v/1000];
+		// u is value, v is 1/10ths (allows for 9.2M format)
+		if (u >= 10) {
+			// value is >= 10: use "123M', " 12M" formats
+			c = buf[0] = " 123456789"[u/100];
 			if (c != ' ') fmt = "0123456789";
-			buf[1] = fmt[v/100%10];
-			buf[2] = "0123456789"[v/10%10];
-		} else {	// scaled value is <10: use 1.2M format
-			buf[0] = "0123456789"[v/10];
+			v = u % 10;
+			u = u / 10;
+			buf[1] = fmt[u%10];
+		} else {
+			// value is < 10: use "9.2M" format
+			buf[0] = "0123456789"[u];
 			buf[1] = '.';
-			buf[2] = "0123456789"[v%10];
 		}
+		buf[2] = "0123456789"[v];
 		// see http://en.wikipedia.org/wiki/Tera
 		buf[3] = " kMGTPEZY"[idx];
 	}
@@ -470,7 +479,8 @@ char *xasprintf(const char *format, ...)
 	va_end(p);
 #endif
 
-	if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
+	if (r < 0)
+		bb_error_msg_and_die(bb_msg_memory_exhausted);
 	return string_ptr;
 }
 
diff --git a/procps/top.c b/procps/top.c
index c02a959e0..abc7a4363 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -448,7 +448,7 @@ static void display_status(int count, int scr_width)
 #endif
 
 		if (s->vsz >= 100*1024)
-			sprintf(vsz_str_buf, "%6ldM", s->vsz/1024);
+			sprintf(vsz_str_buf, "%6ldm", s->vsz/1024);
 		else
 			sprintf(vsz_str_buf, "%7ld", s->vsz);
 		// PID PPID USER STAT VSZ %MEM [%CPU] COMMAND
@@ -519,23 +519,29 @@ int top_main(int argc, char **argv);
 int top_main(int argc, char **argv)
 {
 	int count, lines, col;
-	unsigned interval = 5; /* default update rate is 5 seconds */
-	unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
+	unsigned interval;
+	int iterations = -1; /* infinite */
 	char *sinterval, *siterations;
 #if ENABLE_FEATURE_USE_TERMIOS
 	struct termios new_settings;
-	struct timeval tv;
-	fd_set readfds;
+	struct pollfd pfd[1];
 	unsigned char c;
+
+	pfd[0].fd = 0;
+	pfd[0].events = POLLIN;
 #endif /* FEATURE_USE_TERMIOS */
 
-	interval = 5;
+	interval = 5; /* default update rate is 5 seconds */
 
 	/* do normal option parsing */
 	opt_complementary = "-";
 	getopt32(argv, "d:n:b", &sinterval, &siterations);
-	if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
-	if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
+	if (option_mask32 & 0x1) {
+		/* Need to limit it to not overflow poll timeout */
+		interval = xatou16(sinterval); // -d
+	}
+	if (option_mask32 & 0x2)
+		iterations = xatoi_u(siterations); // -n
 	//if (option_mask32 & 0x4) // -b
 
 	/* change to /proc */
@@ -584,9 +590,8 @@ int top_main(int argc, char **argv)
 				| PSSCAN_UTIME
 				| PSSCAN_STATE
 				| PSSCAN_COMM
-				| PSSCAN_SID
 				| PSSCAN_UIDGID
-		))) {
+		)) != NULL) {
 			int n = ntop;
 			top = xrealloc(top, (++ntop) * sizeof(*top));
 			top[n].pid = p->pid;
@@ -622,15 +627,9 @@ int top_main(int argc, char **argv)
 		/* show status for each of the processes */
 		display_status(count, col);
 #if ENABLE_FEATURE_USE_TERMIOS
-		tv.tv_sec = interval;
-		tv.tv_usec = 0;
-		FD_ZERO(&readfds);
-		FD_SET(0, &readfds);
-		select(1, &readfds, NULL, NULL, &tv);
-		if (FD_ISSET(0, &readfds)) {
-			if (read(0, &c, 1) <= 0) {   /* signal */
-				return EXIT_FAILURE;
-			}
+		if (poll(pfd, 1, interval * 1000) != 0) {
+			if (read(0, &c, 1) != 1)    /* signal */
+				break;
 			if (c == 'q' || c == initial_settings.c_cc[VINTR])
 				break;
 			if (c == 'M') {
@@ -662,7 +661,7 @@ int top_main(int argc, char **argv)
 #endif
 			}
 		}
-		if (!--iterations)
+		if (iterations >= 0 && !--iterations)
 			break;
 #else
 		sleep(interval);