nmeter: new applet. ~4k

Fix build proble on x86_64

8 files changed, 933 insertions, 13 deletions

diff --git a/Makefile.flags b/Makefile.flags
index a6ad10bf6..200cf70c7 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -13,7 +13,6 @@ CPPFLAGS += \
 	-D"BB_VER=KBUILD_STR($(BB_VER))" -DBB_BT=AUTOCONF_TIMESTAMP \
 	-Wall -Wstrict-prototypes -Wshadow -Werror \
 	-funsigned-char -fno-builtin-strlen -finline-limit=0 -static-libgcc \
-	-Os -mpreferred-stack-boundary=2 \
-	-falign-functions=1 -falign-jumps=1 -falign-loops=1 \
+	-Os -falign-functions=1 -falign-jumps=1 -falign-loops=1 \
 	-fomit-frame-pointer -ffunction-sections -fdata-sections \
 	-funsigned-char -fno-builtin-strlen \
diff --git a/arch/i386/Makefile b/arch/i386/Makefile
index b9af293a0..0a235921c 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -2,4 +2,4 @@
 # Build system
 # ==========================================================================
 
-CPPFLAGS += -march=i386
+CPPFLAGS += -march=i386 -mpreferred-stack-boundary=2
diff --git a/include/applets.h b/include/applets.h
index 328848478..3b759de20 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -207,6 +207,7 @@ USE_NAMEIF(APPLET(nameif, _BB_DIR_SBIN, _BB_SUID_NEVER))
 USE_NC(APPLET(nc, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_NETSTAT(APPLET(netstat, _BB_DIR_BIN, _BB_SUID_NEVER))
 USE_NICE(APPLET(nice, _BB_DIR_BIN, _BB_SUID_NEVER))
+USE_NMETER(APPLET(nmeter, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_NOHUP(APPLET(nohup, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_NSLOOKUP(APPLET(nslookup, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_OD(APPLET(od, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
diff --git a/include/usage.h b/include/usage.h
index ef348a2a9..b119c55c1 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2172,6 +2172,30 @@ USE_FEATURE_MDEV_CONFIG( \
 	"Options:\n" \
 	"\t-n ADJUST\tAdjust the scheduling priority by ADJUST"
 
+#define nmeter_trivial_usage \
+	"format_string"
+#define nmeter_full_usage \
+	"Nmeter monitors your system in real time.\n\n" \
+	"Format specifiers:\n" \
+	"%Nc or %[cN]	monitor CPU. N - bar size, default 10\n" \
+	"		(displays: S:system U:user N:niced D:iowait I:irq i:softirq)\n" \
+	"%[niface]	monitor network interface 'iface'\n" \
+	"%m		monitor allocated memory\n" \
+	"%[mf]		monitor free memory\n" \
+	"%[mt]		monitor total memory\n" \
+	"%s		monitor allocated swap\n" \
+	"%f		monitor number of used file descriptors\n" \
+	"%Ni		monitor total/specific IRQ rate\n" \
+	"%x		monitor context switch rate\n" \
+	"%p		monitor forks\n" \
+	"%[pn]		monitor # of processes\n" \
+	"%b		monitor block io\n" \
+	"%Nt		show time (with N decimal points)\n" \
+	"%Nd		milliseconds between updates (default=1000)\n" \
+	"%r		print <cr> instead of <lf> at EOL"
+#define nmeter_example_usage \
+	"nmeter '%250d%t %20c int %i bio %b mem %m forks%p'"
+
 #define nohup_trivial_usage \
 	"COMMAND [ARGS]"
 #define nohup_full_usage \
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index de765a32d..84281105c 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -114,10 +114,9 @@ int xopen3(const char *pathname, int flags, int mode)
 void xread(int fd, void *buf, size_t count)
 {
 	while (count) {
-		ssize_t size;
-
-		if ((size = safe_read(fd, buf, count)) < 1)
-			bb_error_msg_and_die("Short read");
+		ssize_t size = safe_read(fd, buf, count);
+		if (size < 1)
+			bb_error_msg_and_die("short read");
 		count -= size;
 		buf = ((char *) buf) + size;
 	}
@@ -127,10 +126,9 @@ void xread(int fd, void *buf, size_t count)
 void xwrite(int fd, void *buf, size_t count)
 {
 	while (count) {
-		ssize_t size;
-
-		if ((size = safe_write(fd, buf, count)) < 1)
-			bb_error_msg_and_die("Short write");
+		ssize_t size = safe_write(fd, buf, count);
+		if (size < 1)
+			bb_error_msg_and_die("short write");
 		count -= size;
 		buf = ((char *) buf) + size;
 	}
@@ -149,7 +147,7 @@ unsigned char xread_char(int fd)
 
 	xread(fd, &tmp, 1);
 
-	return(tmp);
+	return tmp;
 }
 
 // Die with supplied error message if this FILE * has ferror set.
@@ -220,7 +218,7 @@ int wait4pid(int pid)
 
 void xsetenv(const char *key, const char *value)
 {
-	if(setenv(key, value, 1))
+	if (setenv(key, value, 1))
 		bb_error_msg_and_die(bb_msg_memory_exhausted);
 }
 
diff --git a/miscutils/Config.in b/miscutils/Config.in
index 311c7135c..5d0ec8a42 100644
--- a/miscutils/Config.in
+++ b/miscutils/Config.in
@@ -278,6 +278,12 @@ config MT
 	  to advance or rewind a tape past a specified number of archive
 	  files on the tape.
 
+config NMETER
+	bool "nmeter"
+	default n
+	help
+	  nmeter prints various system parameters continuously.
+
 config READAHEAD
         bool "readahead"
 	default n
diff --git a/miscutils/Kbuild b/miscutils/Kbuild
index 1c9e9fded..3173e1dab 100644
--- a/miscutils/Kbuild
+++ b/miscutils/Kbuild
@@ -18,6 +18,7 @@ lib-$(CONFIG_LESS)        += less.o
 lib-$(CONFIG_MAKEDEVS)    += makedevs.o
 lib-$(CONFIG_MOUNTPOINT)  += mountpoint.o
 lib-$(CONFIG_MT)          += mt.o
+lib-$(CONFIG_NMETER)      += nmeter.o
 lib-$(CONFIG_READAHEAD)   += readahead.o
 lib-$(CONFIG_RUNLEVEL)    += runlevel.o
 lib-$(CONFIG_RX)          += rx.o
diff --git a/miscutils/nmeter.c b/miscutils/nmeter.c
new file mode 100644
index 000000000..e83de38ec
--- /dev/null
+++ b/miscutils/nmeter.c
@@ -0,0 +1,891 @@
+/*
+** Licensed under the GPL v2, see the file LICENSE in this tarball
+**
+** Based on nanotop.c from floppyfw project
+**
+** Contact me: vda.linux@googlemail.com */
+
+//TODO:
+// simplify code
+// /proc/locks
+// /proc/stat:
+// disk_io: (3,0):(22272,17897,410702,4375,54750)
+// btime 1059401962
+
+#include "busybox.h"
+#include <time.h>
+
+typedef unsigned long long ullong;
+typedef unsigned long ulong;
+
+enum { proc_file_size = 4096 };
+
+typedef struct proc_file {
+	char *name;
+	int gen;
+	char *file;
+} proc_file;
+
+static proc_file proc_stat = { "/proc/stat", -1 };
+static proc_file proc_loadavg = { "/proc/loadavg", -1 };
+static proc_file proc_net_dev = { "/proc/net/dev", -1 };
+static proc_file proc_meminfo = { "/proc/meminfo", -1 };
+static proc_file proc_diskstats = { "/proc/diskstats", -1 };
+// Sample #
+static int gen = -1;
+// Linux 2.6? (otherwise assumes 2.4)
+static int is26 = 0;
+static struct timeval tv;
+static int delta = 1000000;
+static int deltanz = 1000000;
+static int need_seconds = 0;
+static char *final_str = "\n";
+
+// We depend on this being a char[], not char* - we take sizeof() of it
+#define outbuf bb_common_bufsiz1
+static char *cur_outbuf = outbuf;
+
+
+static inline void reset_outbuf(void)
+{
+	cur_outbuf = outbuf;
+}
+
+static inline int outbuf_count(void)
+{
+	return cur_outbuf - outbuf;
+}
+
+static void print_outbuf(void)
+{
+	int sz = cur_outbuf - outbuf;
+	if (sz > 0) {
+		write(1, outbuf, sz);
+		cur_outbuf = outbuf;
+	}
+}
+
+static void put(const char *s)
+{
+	int sz = strlen(s);
+	if (sz > outbuf + sizeof(outbuf) - cur_outbuf)
+		sz = outbuf + sizeof(outbuf) - cur_outbuf;
+	memcpy(cur_outbuf, s, sz);
+	cur_outbuf += sz;
+}
+
+static void put_c(char c)
+{
+	if (cur_outbuf < outbuf + sizeof(outbuf))
+		*cur_outbuf++ = c;
+}
+
+static void put_question_marks(int count)
+{
+	while (count--)
+		put_c('?');
+}
+
+static int readfile_z(char *buf, int sz, const char* fname)
+{
+	int fd;
+	fd = xopen(fname, O_RDONLY);
+	// We are not checking for short reads (valid only because
+	// we are reading /proc files)
+	sz = read(fd, buf, sz-1);
+	close(fd);
+	if (sz < 0) {
+		buf[0] = '\0';
+		return 1;
+	}
+	buf[sz] = '\0';
+	return 0;
+}
+
+static const char* get_file(proc_file *pf)
+{
+	if (pf->gen != gen) {
+		pf->gen = gen;
+		// We allocate proc_file_size bytes. This wastes memory,
+		// but allows us to allocate only once (at first sample)
+		// per proc file, and reuse buffer for each sample
+		if (!pf->file)
+			pf->file = (char*)xmalloc(proc_file_size);
+		readfile_z(pf->file, proc_file_size, pf->name);
+	}
+	return pf->file;
+}
+
+static inline ullong read_after_slash(const char *p)
+{
+	p = strchr(p, '/');
+	if (!p) return 0;
+	return strtoull(p+1, NULL, 10);
+}
+
+enum conv_type { conv_decimal, conv_slash };
+
+// Reads decimal values from line. Values start after key, for example:
+// "cpu  649369 0 341297 4336769..." - key is "cpu" here.
+// Values are stored in vec[]. arg_ptr has list of positions
+// we are interested in: for example: 1,2,5 - we want 1st, 2nd and 5th value.
+static int vrdval(const char* p, const char* key,
+	enum conv_type conv, ullong *vec, va_list arg_ptr)
+{
+	int indexline;
+	int indexnext;
+
+	p = strstr(p, key);
+	if (!p) return 1;
+
+	p += strlen(key);
+	indexline = 1;
+	indexnext = va_arg(arg_ptr, int);
+	while (1) {
+		while (*p == ' ' || *p == '\t') p++;
+		if (*p == '\n' || *p == '\0') break;
+
+		if (indexline == indexnext) { // read this value
+			*vec++ = conv==conv_decimal ?
+				strtoull(p, NULL, 10) :
+				read_after_slash(p);
+			indexnext = va_arg(arg_ptr, int);
+		}
+		while (*p > ' ') p++; // skip over value
+		indexline++;
+	}
+	return 0;
+}
+
+// Parses files with lines like "cpu0 21727 0 15718 1813856 9461 10485 0 0":
+// rdval(file_contents, "string_to_find", result_vector, value#, value#...)
+// value# start with 1
+static int rdval(const char* p, const char* key, ullong *vec, ...)
+{
+	va_list arg_ptr;
+	int result;
+
+	va_start(arg_ptr, vec);
+	result = vrdval(p, key, conv_decimal, vec, arg_ptr);
+	va_end(arg_ptr);
+
+	return result;
+}
+
+// Parses files with lines like "... ... ... 3/148 ...."
+static int rdval_loadavg(const char* p, ullong *vec, ...)
+{
+	va_list arg_ptr;
+	int result;
+
+	va_start(arg_ptr, vec);
+	result = vrdval(p, "", conv_slash, vec, arg_ptr);
+	va_end(arg_ptr);
+
+	return result;
+}
+
+// Parses /proc/diskstats
+//   1  2 3   4	 5        6(rd)  7      8     9     10(wr) 11     12 13     14
+//   3  0 hda 51292 14441 841783 926052 25717 79650 843256 3029804 0 148459 3956933
+//   3  1 hda1 0 0 0 0 <- ignore if only 4 fields
+static int rdval_diskstats(const char* p, ullong *vec)
+{
+	ullong rd = 0; // to avoid "warning: 'rd' might be used uninitialized"
+	int indexline = 0;
+	vec[0] = 0;
+	vec[1] = 0;
+	while (1) {
+		indexline++;
+		while (*p == ' ' || *p == '\t') p++;
+		if (*p == '\0') break;
+		if (*p == '\n') {
+			indexline = 0;
+			p++;
+			continue;
+		}
+		if (indexline == 6) {
+			rd = strtoull(p, NULL, 10);
+		} else if (indexline == 10) {
+			vec[0] += rd;  // TODO: *sectorsize (don't know how to find out sectorsize)
+			vec[1] += strtoull(p, NULL, 10);
+			while (*p != '\n' && *p != '\0') p++;
+			continue;
+		}
+		while (*p > ' ') p++; // skip over value
+	}
+	return 0;
+}
+
+static void scale(ullong ul)
+{
+	char *fmt;
+	char buf[5];
+	char c;
+	unsigned v,idx = 0;
+	ul *= 10;
+	if (ul > 9999*10) { // do not scale if 9999 or less
+		while (ul >= 10000) {
+			ul /= 1024;
+			idx++;
+		}
+	}
+	v = ul; // ullong divisions are expensive, avoid them
+
+	fmt = " 123456789";
+	if (!idx) {		// 9999 or less: use 1234 format
+		c = buf[0] = " 123456789"[v/10000];
+		if (c!=' ') fmt = "0123456789";
+		c = buf[1] = fmt[v/1000%10];
+		if (c!=' ') fmt = "0123456789";
+		buf[2] = fmt[v/100%10];
+		buf[3] = "0123456789"[v/10%10];
+	} else {
+		if (v>=10*10) {	// scaled value is >=10: use 123M format
+			c = buf[0] = " 123456789"[v/1000];
+			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];
+			buf[1] = '.';
+			buf[2] = "0123456789"[v%10];
+		}
+		// see http://en.wikipedia.org/wiki/Tera
+		buf[3] = " kMGTPEZY"[idx];
+	}
+	buf[4] = '\0';
+	put(buf);
+}
+
+
+#define S_STAT(a) \
+typedef struct a { \
+	struct s_stat *next; \
+	void (*collect)(struct a *s); \
+	const char *label;
+#define S_STAT_END(a) } a;
+
+S_STAT(s_stat)
+S_STAT_END(s_stat)
+
+static void collect_literal(s_stat *s)
+{
+}
+
+static s_stat* init_literal(void)
+{
+	s_stat *s = xmalloc(sizeof(s_stat));
+	s->collect = collect_literal;
+	return (s_stat*)s;
+}
+
+static s_stat* init_delay(const char *param)
+{
+	delta = strtol(param, NULL, 0)*1000;
+	deltanz = delta > 0 ? delta : 1;
+	need_seconds = (1000000%deltanz) != 0;
+	return (s_stat*)0;
+}
+
+static s_stat* init_cr(const char *param)
+{
+	final_str = "\r";
+	return (s_stat*)0;
+}
+
+
+//     user nice system idle  iowait irq  softirq (last 3 only in 2.6)
+//cpu  649369 0 341297 4336769 11640 7122 1183
+//cpuN 649369 0 341297 4336769 11640 7122 1183
+enum { CPU_FIELDCNT = 7 };
+S_STAT(cpu_stat)
+	ullong old[CPU_FIELDCNT];
+	int bar_sz;
+	char *bar;
+S_STAT_END(cpu_stat)
+
+
+static void collect_cpu(cpu_stat *s)
+{
+	ullong data[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
+	unsigned frac[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
+	ullong all = 0;
+	int norm_all = 0;
+	int bar_sz = s->bar_sz;
+	char *bar = s->bar;
+	int i;
+
+	if (rdval(get_file(&proc_stat), "cpu ", data, 1, 2, 3, 4, 5, 6, 7)) {
+		put_question_marks(bar_sz);
+		return;
+	}
+
+	for (i=0; i<CPU_FIELDCNT; i++) {
+		ullong old = s->old[i];
+		if (data[i] < old) old = data[i];		//sanitize
+		s->old[i] = data[i];
+		all += (data[i] -= old);
+	}
+
+	if (all) {
+		for (i=0; i<CPU_FIELDCNT; i++) {
+			ullong t = bar_sz * data[i];
+			norm_all += data[i] = t / all;
+			frac[i] = t % all;
+		}
+
+		while (norm_all < bar_sz) {
+			unsigned max = frac[0];
+			int pos = 0;
+			for (i=1; i<CPU_FIELDCNT; i++) {
+				if (frac[i] > max) max = frac[i], pos = i;
+			}
+			frac[pos] = 0;	//avoid bumping up same value twice
+			data[pos]++;
+			norm_all++;
+		}
+
+		memset(bar, '.', bar_sz);
+		memset(bar, 'S', data[2]); bar += data[2]; //sys
+		memset(bar, 'U', data[0]); bar += data[0]; //usr
+		memset(bar, 'N', data[1]); bar += data[1]; //nice
+		memset(bar, 'D', data[4]); bar += data[4]; //iowait
+		memset(bar, 'I', data[5]); bar += data[5]; //irq
+		memset(bar, 'i', data[6]); bar += data[6]; //softirq
+	} else {
+		memset(bar, '?', bar_sz);
+	}
+	put(s->bar);
+}
+
+
+static s_stat* init_cpu(const char *param)
+{
+	int sz;
+	cpu_stat *s = xmalloc(sizeof(cpu_stat));
+	s->collect = collect_cpu;
+	sz = strtol(param, NULL, 0);
+	if (sz < 10) sz = 10;
+	if (sz > 1000) sz = 1000;
+	s->bar = xmalloc(sz+1);
+	s->bar[sz] = '\0';
+	s->bar_sz = sz;
+	return (s_stat*)s;
+}
+
+
+S_STAT(int_stat)
+	ullong old;
+	int no;
+S_STAT_END(int_stat)
+
+static void collect_int(int_stat *s)
+{
+	ullong data[1];
+	ullong old;
+
+	if (rdval(get_file(&proc_stat), "intr", data, s->no)) {
+		put_question_marks(4);
+		return;
+	}
+
+	old = s->old;
+	if (data[0] < old) old = data[0];		//sanitize
+	s->old = data[0];
+	scale(data[0] - old);
+}
+
+static s_stat* init_int(const char *param)
+{
+	int_stat *s = xmalloc(sizeof(int_stat));
+	s->collect = collect_int;
+	if (param[0]=='\0') {
+		s->no = 1;
+	} else {
+		int n = strtoul(param, NULL, 0);
+		s->no = n+2;
+	}
+	return (s_stat*)s;
+}
+
+
+S_STAT(ctx_stat)
+	ullong old;
+S_STAT_END(ctx_stat)
+
+static void collect_ctx(ctx_stat *s)
+{
+	ullong data[1];
+	ullong old;
+
+	if (rdval(get_file(&proc_stat), "ctxt", data, 1)) {
+		put_question_marks(4);
+		return;
+	}
+
+	old = s->old;
+	if (data[0] < old) old = data[0];		//sanitize
+	s->old = data[0];
+	scale(data[0] - old);
+}
+
+static s_stat* init_ctx(const char *param)
+{
+	ctx_stat *s = xmalloc(sizeof(ctx_stat));
+	s->collect = collect_ctx;
+	return (s_stat*)s;
+}
+
+
+S_STAT(blk_stat)
+	const char* lookfor;
+	ullong old[2];
+S_STAT_END(blk_stat)
+
+static void collect_blk(blk_stat *s)
+{
+	ullong data[2];
+	int i;
+
+	if (is26) {
+		i = rdval_diskstats(get_file(&proc_diskstats), data);
+	} else {
+		i = rdval(get_file(&proc_stat), s->lookfor, data, 1, 2);
+		// Linux 2.4 reports bio in Kbytes, convert to sectors:
+		data[0] *= 2;
+		data[1] *= 2;
+	}
+	if (i) {
+		put_question_marks(9);
+		return;
+	}
+
+	for (i=0; i<2; i++) {
+		ullong old = s->old[i];
+		if (data[i] < old) old = data[i];		//sanitize
+		s->old[i] = data[i];
+		data[i] -= old;
+	}
+	scale(data[0]*512); // TODO: *sectorsize
+	put_c(' ');
+	scale(data[1]*512);
+}
+
+static s_stat* init_blk(const char *param)
+{
+	blk_stat *s = xmalloc(sizeof(blk_stat));
+	s->collect = collect_blk;
+	s->lookfor = "page";
+	return (s_stat*)s;
+}
+
+
+S_STAT(fork_stat)
+	ullong old;
+S_STAT_END(fork_stat)
+
+static void collect_thread_nr(fork_stat *s)
+{
+	ullong data[1];
+
+	if (rdval_loadavg(get_file(&proc_loadavg), data, 4)) {
+		put_question_marks(4);
+		return;
+	}
+	scale(data[0]);
+}
+
+static void collect_fork(fork_stat *s)
+{
+	ullong data[1];
+	ullong old;
+
+	if (rdval(get_file(&proc_stat), "processes", data, 1)) {
+		put_question_marks(4);
+		return;
+	}
+
+	old = s->old;
+	if (data[0] < old) old = data[0];	//sanitize
+	s->old = data[0];
+	scale(data[0] - old);
+}
+
+static s_stat* init_fork(const char *param)
+{
+	fork_stat *s = xmalloc(sizeof(fork_stat));
+	if (*param == 'n') {
+		s->collect = collect_thread_nr;
+	} else {
+		s->collect = collect_fork;
+	}
+	return (s_stat*)s;
+}
+
+
+S_STAT(if_stat)
+	ullong old[4];
+	const char *device;
+	char *device_colon;
+S_STAT_END(if_stat)
+
+static void collect_if(if_stat *s)
+{
+	ullong data[4];
+	int i;
+
+	if (rdval(get_file(&proc_net_dev), s->device_colon, data, 1, 3, 9, 11)) {
+		put_question_marks(10);
+		return;
+	}
+
+	for (i=0; i<4; i++) {
+		ullong old = s->old[i];
+		if (data[i] < old) old = data[i];		//sanitize
+		s->old[i] = data[i];
+		data[i] -= old;
+	}
+	put_c(data[1] ? '*' : ' ');
+	scale(data[0]);
+	put_c(data[3] ? '*' : ' ');
+	scale(data[2]);
+}
+
+static s_stat* init_if(const char *device)
+{
+	if_stat *s = xmalloc(sizeof(if_stat));
+
+	if (!device || !device[0])
+		bb_show_usage();
+	s->collect = collect_if;
+
+	s->device = device;
+	s->device_colon = xmalloc(strlen(device)+2);
+	strcpy(s->device_colon, device);
+	strcat(s->device_colon, ":");
+	return (s_stat*)s;
+}
+
+
+S_STAT(mem_stat)
+	char opt;
+S_STAT_END(mem_stat)
+
+// "Memory" value should not include any caches.
+// IOW: neither "ls -laR /" nor heavy read/write activity
+//      should affect it. We'd like to also include any
+//      long-term allocated kernel-side mem, but it is hard
+//      to figure out. For now, bufs, cached & slab are
+//      counted as "free" memory
+//2.6.16:
+//MemTotal:       773280 kB
+//MemFree:         25912 kB - genuinely free
+//Buffers:        320672 kB - cache
+//Cached:         146396 kB - cache
+//SwapCached:          0 kB
+//Active:         183064 kB
+//Inactive:       356892 kB
+//HighTotal:           0 kB
+//HighFree:            0 kB
+//LowTotal:       773280 kB
+//LowFree:         25912 kB
+//SwapTotal:      131064 kB
+//SwapFree:       131064 kB
+//Dirty:              48 kB
+//Writeback:           0 kB
+//Mapped:          96620 kB
+//Slab:           200668 kB - takes 7 Mb on my box fresh after boot,
+//                            but includes dentries and inodes
+//                            (== can take arbitrary amount of mem)
+//CommitLimit:    517704 kB
+//Committed_AS:   236776 kB
+//PageTables:       1248 kB
+//VmallocTotal:   516052 kB
+//VmallocUsed:      3852 kB
+//VmallocChunk:   512096 kB
+//HugePages_Total:     0
+//HugePages_Free:      0
+//Hugepagesize:     4096 kB
+static void collect_mem(mem_stat *s)
+{
+	ullong m_total = 0;
+	ullong m_free = 0;
+	ullong m_bufs = 0;
+	ullong m_cached = 0;
+	ullong m_slab = 0;
+
+	if (rdval(get_file(&proc_meminfo), "MemTotal:", &m_total, 1)) {
+		put_question_marks(4);
+		return;
+	}
+	if (s->opt == 'f') {
+		scale(m_total << 10);
+		return;
+	}
+
+	if (rdval(proc_meminfo.file, "MemFree:", &m_free  , 1)
+	 || rdval(proc_meminfo.file, "Buffers:", &m_bufs  , 1)
+	 || rdval(proc_meminfo.file, "Cached:",  &m_cached, 1)
+	 || rdval(proc_meminfo.file, "Slab:",    &m_slab  , 1)
+	) {
+		put_question_marks(4);
+		return;
+	}
+
+	m_free += m_bufs + m_cached + m_slab;
+	switch(s->opt) {
+	case 'f':
+		scale(m_free << 10); break;
+	default:
+		scale((m_total - m_free) << 10); break;
+	}
+}
+
+static s_stat* init_mem(const char *param)
+{
+	mem_stat *s = xmalloc(sizeof(mem_stat));
+	s->collect = collect_mem;
+	s->opt = param[0];
+	return (s_stat*)s;
+}
+
+
+S_STAT(swp_stat)
+S_STAT_END(swp_stat)
+
+static void collect_swp(swp_stat *s)
+{
+	ullong s_total[1];
+	ullong s_free[1];
+	if (rdval(get_file(&proc_meminfo), "SwapTotal:", s_total, 1)
+	 || rdval(proc_meminfo.file,       "SwapFree:" , s_free,  1)
+	) {
+		put_question_marks(4);
+		return;
+	}
+	scale((s_total[0]-s_free[0]) << 10);
+}
+
+static s_stat* init_swp(const char *param)
+{
+	swp_stat *s = xmalloc(sizeof(swp_stat));
+	s->collect = collect_swp;
+	return (s_stat*)s;
+}
+
+
+S_STAT(fd_stat)
+S_STAT_END(fd_stat)
+
+static void collect_fd(fd_stat *s)
+{
+	char file[4096];
+	ullong data[2];
+
+	readfile_z(file, sizeof(file), "/proc/sys/fs/file-nr");
+	if (rdval(file, "", data, 1, 2)) {
+		put_question_marks(4);
+		return;
+	}
+
+	scale(data[0] - data[1]);
+}
+
+static s_stat* init_fd(const char *param)
+{
+	fd_stat *s = xmalloc(sizeof(fd_stat));
+	s->collect = collect_fd;
+	return (s_stat*)s;
+}
+
+
+S_STAT(time_stat)
+	int prec;
+	int scale;
+S_STAT_END(time_stat)
+
+static void collect_time(time_stat *s)
+{
+	char buf[sizeof("12:34:56.123456")];
+	struct tm* tm;
+	int us = tv.tv_usec + s->scale/2;
+	time_t t = tv.tv_sec;
+
+	if (us >= 1000000) {
+		t++;
+		us -= 1000000;
+	}
+	tm = localtime(&t);
+
+	sprintf(buf, "%02d:%02d:%02d", tm->tm_hour, tm->tm_min, tm->tm_sec);
+	if (s->prec)
+		sprintf(buf+8, ".%0*d", s->prec, us / s->scale);
+	put(buf);
+}
+
+static s_stat* init_time(const char *param)
+{
+	int prec;
+	time_stat *s = xmalloc(sizeof(time_stat));
+
+	s->collect = collect_time;
+	prec = param[0]-'0';
+	if (prec < 0) prec = 0;
+	else if (prec > 6) prec = 6;
+	s->prec = prec;
+	s->scale = 1;
+	while (prec++ < 6)
+		s->scale *= 10;
+	return (s_stat*)s;
+}
+
+static void collect_info(s_stat *s)
+{
+	gen++;
+	while (s) {
+		put(s->label);
+		s->collect(s);
+		s = s->next;
+	}
+}
+
+
+typedef s_stat* init_func(const char *param);
+
+static const char options[] = "ncmsfixptbdr";
+static init_func* init_functions[] = {
+	init_if,
+	init_cpu,
+	init_mem,
+	init_swp,
+	init_fd,
+	init_int,
+	init_ctx,
+	init_fork,
+	init_time,
+	init_blk,
+	init_delay,
+	init_cr,
+};
+
+int nmeter_main(int argc, char* argv[])
+{
+	char buf[32];
+	s_stat *first = NULL;
+	s_stat *last = NULL;
+	s_stat *s;
+	char *cur, *prev;
+	int fd;
+
+	if (argc != 2)
+		bb_show_usage();
+
+	fd = xopen("/proc/version", O_RDONLY);
+	if (read(fd, buf, sizeof(buf)) > 0)
+		is26 = (strstr(buf, "Linux version 2.4.")==NULL);
+	close(fd);
+
+	// Can use argv[1] directly, but this will mess up
+	// parameters as seen by e.g. ps. Making a copy...
+	cur = xstrdup(argv[1]);
+	while (1) {
+		char *param, *p;
+		prev = cur;
+again:
+		cur = strchr(cur, '%');
+		if (!cur)
+			break;
+		if (cur[1]=='%') {	// %%
+			strcpy(cur, cur+1);
+			cur++;
+			goto again;
+		}
+		*cur++ = '\0';		// overwrite %
+		if (cur[0] == '[') {
+			// format: %[foptstring]
+			cur++;
+			p = strchr(options, cur[0]);
+			param = cur+1;
+			while (cur[0] != ']') {
+				if (!cur[0])
+					bb_show_usage();
+				cur++;
+			}
+			*cur++ = '\0';	// overwrite [
+		} else {
+			// format: %NNNNNNf
+			param = cur;
+			while (cur[0] >= '0' && cur[0] <= '9')
+				cur++;
+			if (!cur[0])
+				bb_show_usage();
+			p = strchr(options, cur[0]);
+			*cur++ = '\0';	// overwrite format char
+		}
+		if (!p)
+			bb_show_usage();
+		s = init_functions[p-options](param);
+		if (s) {
+			s->label = prev;
+			s->next = 0;
+			if (!first)
+				first = s;
+			else
+				last->next = s;
+			last = s;
+		} else {
+			// %NNNNd or %r option. remove it from string
+			strcpy(prev + strlen(prev), cur);
+			cur = prev;
+		}
+	}
+	if (prev[0]) {
+		s = init_literal();
+		s->label = prev;
+		s->next = 0;
+		if (!first)
+			first = s;
+		else
+			last->next = s;
+		last = s;
+	}
+
+	// Generate first samples but do not print them, they're bogus
+	collect_info(first);
+	reset_outbuf();
+	if (delta >= 0) {
+		gettimeofday(&tv, 0);
+		usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
+	}
+
+	while (1) {
+		gettimeofday(&tv, 0);
+		collect_info(first);
+		put(final_str);
+		print_outbuf();
+
+		// Negative delta -> no usleep at all
+		// This will hog the CPU but you can have REALLY GOOD
+		// time resolution ;)
+		// TODO: detect and avoid useless updates
+		// (like: nothing happens except time)
+		if (delta >= 0) {
+			int rem;
+			// can be commented out, will sacrifice sleep time precision a bit
+			gettimeofday(&tv, 0);
+			if (need_seconds)
+				rem = delta - ((ullong)tv.tv_sec*1000000+tv.tv_usec)%deltanz;
+			else
+				rem = delta - tv.tv_usec%deltanz;
+			// Sometimes kernel wakes us up just a tiny bit earlier than asked
+			// Do not go to very short sleep in this case
+			if (rem < delta/128) {
+				rem += delta;
+			}
+			usleep(rem);
+		}
+	}
+
+	return 0;
+}