busybox/procps/nmeter.c

/*
** 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
//TODO: use sysinfo libc call/syscall, if appropriate
// (faster than open/read/close):
// sysinfo({uptime=15017, loads=[5728, 15040, 16480]
//  totalram=2107416576, freeram=211525632, sharedram=0, bufferram=157204480}
//  totalswap=134209536, freeswap=134209536, procs=157})

#include <time.h>
#include "libbb.h"

typedef unsigned long long ullong;

enum {  /* Preferably use powers of 2 */
	PROC_MIN_FILE_SIZE = 256,
	PROC_MAX_FILE_SIZE = 16 * 1024,
};

typedef struct proc_file {
	char *file;
	int file_sz;
	smallint last_gen;
} proc_file;

static const char *const proc_name[] = {
	"stat",		// Must match the order of proc_file's!
	"loadavg",
	"net/dev",
	"meminfo",
	"diskstats",
	"sys/fs/file-nr"
};

struct globals {
	// Sample generation flip-flop
	smallint gen;
	// Linux 2.6? (otherwise assumes 2.4)
	smallint is26;
	// 1 if sample delay is not an integer fraction of a second
	smallint need_seconds;
	char *cur_outbuf;
	const char *final_str;
	int delta;
	int deltanz;
	struct timeval tv;
#define first_proc_file proc_stat
	proc_file proc_stat;	// Must match the order of proc_name's!
	proc_file proc_loadavg;
	proc_file proc_net_dev;
	proc_file proc_meminfo;
	proc_file proc_diskstats;
	proc_file proc_sys_fs_filenr;
};
#define G (*ptr_to_globals)
#define gen                (G.gen               )
#define is26               (G.is26              )
#define need_seconds       (G.need_seconds      )
#define cur_outbuf         (G.cur_outbuf        )
#define final_str          (G.final_str         )
#define delta              (G.delta             )
#define deltanz            (G.deltanz           )
#define tv                 (G.tv                )
#define proc_stat          (G.proc_stat         )
#define proc_loadavg       (G.proc_loadavg      )
#define proc_net_dev       (G.proc_net_dev      )
#define proc_meminfo       (G.proc_meminfo      )
#define proc_diskstats     (G.proc_diskstats    )
#define proc_sys_fs_filenr (G.proc_sys_fs_filenr)
#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
	cur_outbuf = outbuf; \
	final_str = "\n"; \
	deltanz = delta = 1000000; \
} while (0)

// We depend on this being a char[], not char* - we take sizeof() of it
#define outbuf bb_common_bufsiz1

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) {
		xwrite(STDOUT_FILENO, 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 void readfile_z(proc_file *pf, const char* fname)
{
// open_read_close() will do two reads in order to be sure we are at EOF,
// and we don't need/want that.
	int fd;
	int sz, rdsz;
	char *buf;

	sz = pf->file_sz;
	buf = pf->file;
	if (!buf) {
		buf = xmalloc(PROC_MIN_FILE_SIZE);
		sz = PROC_MIN_FILE_SIZE;
	}
 again:
	fd = xopen(fname, O_RDONLY);
	buf[0] = '\0';
	rdsz = read(fd, buf, sz-1);
	close(fd);
	if (rdsz > 0) {
		if (rdsz == sz-1 && sz < PROC_MAX_FILE_SIZE) {
			sz *= 2;
			buf = xrealloc(buf, sz);
			goto again;
		}
		buf[rdsz] = '\0';
	}
	pf->file_sz = sz;
	pf->file = buf;
}

static const char* get_file(proc_file *pf)
{
	if (pf->last_gen != gen) {
		pf->last_gen = gen;
		readfile_z(pf, proc_name[pf - &first_proc_file]);
	}
	return pf->file;
}

static 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 = rd; // for compiler
	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 buf[5];

	/* see http://en.wikipedia.org/wiki/Tera */
	smart_ulltoa4(ul, buf, " kmgtpezy");
	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 UNUSED_PARAM)
{
}

static s_stat* init_literal(void)
{
	s_stat *s = xzalloc(sizeof(*s));
	s->collect = collect_literal;
	return (s_stat*)s;
}

static s_stat* init_delay(const char *param)
{
	delta = strtoul(param, NULL, 0) * 1000; /* param can be "" */
	deltanz = delta > 0 ? delta : 1;
	need_seconds = (1000000%deltanz) != 0;
	return NULL;
}

static s_stat* init_cr(const char *param UNUSED_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 = xzalloc(sizeof(*s));
	s->collect = collect_cpu;
	sz = strtoul(param, NULL, 0); /* param can be "" */
	if (sz < 10) sz = 10;
	if (sz > 1000) sz = 1000;
	s->bar = xzalloc(sz+1);
	/*s->bar[sz] = '\0'; - xzalloc did it */
	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 = xzalloc(sizeof(*s));
	s->collect = collect_int;
	if (param[0] == '\0') {
		s->no = 1;
	} else {
		int n = xatoi_u(param);
		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 UNUSED_PARAM)
{
	ctx_stat *s = xzalloc(sizeof(*s));
	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 UNUSED_PARAM)
{
	blk_stat *s = xzalloc(sizeof(*s));
	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 UNUSED_PARAM)
{
	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 = xzalloc(sizeof(*s));
	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 = xzalloc(sizeof(*s));

	if (!device || !device[0])
		bb_show_usage();
	s->collect = collect_if;

	s->device = device;
	s->device_colon = xasprintf("%s:", device);
	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 == 't') {
		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 = xzalloc(sizeof(*s));
	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 UNUSED_PARAM)
{
	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 UNUSED_PARAM)
{
	swp_stat *s = xzalloc(sizeof(*s));
	s->collect = collect_swp;
	return (s_stat*)s;
}


S_STAT(fd_stat)
S_STAT_END(fd_stat)

static void collect_fd(fd_stat *s UNUSED_PARAM)
{
	ullong data[2];

	if (rdval(get_file(&proc_sys_fs_filenr), "", data, 1, 2)) {
		put_question_marks(4);
		return;
	}

	scale(data[0] - data[1]);
}

static s_stat* init_fd(const char *param UNUSED_PARAM)
{
	fd_stat *s = xzalloc(sizeof(*s));
	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 = xzalloc(sizeof(*s));

	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 ^= 1;
	while (s) {
		put(s->label);
		s->collect(s);
		s = s->next;
	}
}


typedef s_stat* init_func(const char *param);

static const char options[] ALIGN1 = "ncmsfixptbdr";
static init_func *const 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) MAIN_EXTERNALLY_VISIBLE;
int nmeter_main(int argc, char **argv)
{
	char buf[32];
	s_stat *first = NULL;
	s_stat *last = NULL;
	s_stat *s;
	char *cur, *prev;

	INIT_G();

	xchdir("/proc");

	if (argc != 2)
		bb_show_usage();

	if (open_read_close("version", buf, sizeof(buf)-1) > 0) {
		buf[sizeof(buf)-1] = '\0';
		is26 = (strstr(buf, " 2.4.") == NULL);
	}

	// 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] == '%') {	// %%
			overlapping_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 = NULL; - all initXXX funcs use xzalloc */
			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 = NULL; - all initXXX funcs use xzalloc */
		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, NULL);
		usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
	}

	while (1) {
		gettimeofday(&tv, NULL);
		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, NULL);
			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;*/
}
1	niro	816	/*
2			** Licensed under the GPL v2, see the file LICENSE in this tarball
3			**
4			** Based on nanotop.c from floppyfw project
5			**
6			** Contact me: vda.linux@googlemail.com */
7
8			//TODO:
9			// simplify code
10			// /proc/locks
11			// /proc/stat:
12			// disk_io: (3,0):(22272,17897,410702,4375,54750)
13			// btime 1059401962
14			//TODO: use sysinfo libc call/syscall, if appropriate
15			// (faster than open/read/close):
16			// sysinfo({uptime=15017, loads=[5728, 15040, 16480]
17			// totalram=2107416576, freeram=211525632, sharedram=0, bufferram=157204480}
18			// totalswap=134209536, freeswap=134209536, procs=157})
19
20			#include <time.h>
21			#include "libbb.h"
22
23			typedef unsigned long long ullong;
24
25			enum { /* Preferably use powers of 2 */
26			PROC_MIN_FILE_SIZE = 256,
27			PROC_MAX_FILE_SIZE = 16 * 1024,
28			};
29
30			typedef struct proc_file {
31			char *file;
32			int file_sz;
33			smallint last_gen;
34			} proc_file;
35
36			static const char *const proc_name[] = {
37			"stat", // Must match the order of proc_file's!
38			"loadavg",
39			"net/dev",
40			"meminfo",
41			"diskstats",
42			"sys/fs/file-nr"
43			};
44
45			struct globals {
46			// Sample generation flip-flop
47			smallint gen;
48			// Linux 2.6? (otherwise assumes 2.4)
49			smallint is26;
50			// 1 if sample delay is not an integer fraction of a second
51			smallint need_seconds;
52			char *cur_outbuf;
53			const char *final_str;
54			int delta;
55			int deltanz;
56			struct timeval tv;
57			#define first_proc_file proc_stat
58			proc_file proc_stat; // Must match the order of proc_name's!
59			proc_file proc_loadavg;
60			proc_file proc_net_dev;
61			proc_file proc_meminfo;
62			proc_file proc_diskstats;
63			proc_file proc_sys_fs_filenr;
64			};
65			#define G (*ptr_to_globals)
66			#define gen (G.gen )
67			#define is26 (G.is26 )
68			#define need_seconds (G.need_seconds )
69			#define cur_outbuf (G.cur_outbuf )
70			#define final_str (G.final_str )
71			#define delta (G.delta )
72			#define deltanz (G.deltanz )
73			#define tv (G.tv )
74			#define proc_stat (G.proc_stat )
75			#define proc_loadavg (G.proc_loadavg )
76			#define proc_net_dev (G.proc_net_dev )
77			#define proc_meminfo (G.proc_meminfo )
78			#define proc_diskstats (G.proc_diskstats )
79			#define proc_sys_fs_filenr (G.proc_sys_fs_filenr)
80			#define INIT_G() do { \
81			SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
82			cur_outbuf = outbuf; \
83			final_str = "\n"; \
84			deltanz = delta = 1000000; \
85			} while (0)
86
87			// We depend on this being a char[], not char* - we take sizeof() of it
88			#define outbuf bb_common_bufsiz1
89
90			static inline void reset_outbuf(void)
91			{
92			cur_outbuf = outbuf;
93			}
94
95			static inline int outbuf_count(void)
96			{
97			return cur_outbuf - outbuf;
98			}
99
100			static void print_outbuf(void)
101			{
102			int sz = cur_outbuf - outbuf;
103			if (sz > 0) {
104			xwrite(STDOUT_FILENO, outbuf, sz);
105			cur_outbuf = outbuf;
106			}
107			}
108
109			static void put(const char *s)
110			{
111			int sz = strlen(s);
112			if (sz > outbuf + sizeof(outbuf) - cur_outbuf)
113			sz = outbuf + sizeof(outbuf) - cur_outbuf;
114			memcpy(cur_outbuf, s, sz);
115			cur_outbuf += sz;
116			}
117
118			static void put_c(char c)
119			{
120			if (cur_outbuf < outbuf + sizeof(outbuf))
121			*cur_outbuf++ = c;
122			}
123
124			static void put_question_marks(int count)
125			{
126			while (count--)
127			put_c('?');
128			}
129
130			static void readfile_z(proc_file pf, const char fname)
131			{
132			// open_read_close() will do two reads in order to be sure we are at EOF,
133			// and we don't need/want that.
134			int fd;
135			int sz, rdsz;
136			char *buf;
137
138			sz = pf->file_sz;
139			buf = pf->file;
140			if (!buf) {
141			buf = xmalloc(PROC_MIN_FILE_SIZE);
142			sz = PROC_MIN_FILE_SIZE;
143			}
144			again:
145			fd = xopen(fname, O_RDONLY);
146			buf[0] = '\0';
147			rdsz = read(fd, buf, sz-1);
148			close(fd);
149			if (rdsz > 0) {
150			if (rdsz == sz-1 && sz < PROC_MAX_FILE_SIZE) {
151			sz *= 2;
152			buf = xrealloc(buf, sz);
153			goto again;
154			}
155			buf[rdsz] = '\0';
156			}
157			pf->file_sz = sz;
158			pf->file = buf;
159			}
160
161			static const char* get_file(proc_file *pf)
162			{
163			if (pf->last_gen != gen) {
164			pf->last_gen = gen;
165			readfile_z(pf, proc_name[pf - &first_proc_file]);
166			}
167			return pf->file;
168			}
169
170			static ullong read_after_slash(const char *p)
171			{
172			p = strchr(p, '/');
173			if (!p) return 0;
174			return strtoull(p+1, NULL, 10);
175			}
176
177			enum conv_type { conv_decimal, conv_slash };
178
179			// Reads decimal values from line. Values start after key, for example:
180			// "cpu 649369 0 341297 4336769..." - key is "cpu" here.
181			// Values are stored in vec[]. arg_ptr has list of positions
182			// we are interested in: for example: 1,2,5 - we want 1st, 2nd and 5th value.
183			static int vrdval(const char* p, const char* key,
184			enum conv_type conv, ullong *vec, va_list arg_ptr)
185			{
186			int indexline;
187			int indexnext;
188
189			p = strstr(p, key);
190			if (!p) return 1;
191
192			p += strlen(key);
193			indexline = 1;
194			indexnext = va_arg(arg_ptr, int);
195			while (1) {
196			while (p == ' ' \|\| p == '\t') p++;
197			if (p == '\n' \|\| p == '\0') break;
198
199			if (indexline == indexnext) { // read this value
200			*vec++ = conv==conv_decimal ?
201			strtoull(p, NULL, 10) :
202			read_after_slash(p);
203			indexnext = va_arg(arg_ptr, int);
204			}
205			while (*p > ' ') p++; // skip over value
206			indexline++;
207			}
208			return 0;
209			}
210
211			// Parses files with lines like "cpu0 21727 0 15718 1813856 9461 10485 0 0":
212			// rdval(file_contents, "string_to_find", result_vector, value#, value#...)
213			// value# start with 1
214			static int rdval(const char* p, const char* key, ullong *vec, ...)
215			{
216			va_list arg_ptr;
217			int result;
218
219			va_start(arg_ptr, vec);
220			result = vrdval(p, key, conv_decimal, vec, arg_ptr);
221			va_end(arg_ptr);
222
223			return result;
224			}
225
226			// Parses files with lines like "... ... ... 3/148 ...."
227			static int rdval_loadavg(const char* p, ullong *vec, ...)
228			{
229			va_list arg_ptr;
230			int result;
231
232			va_start(arg_ptr, vec);
233			result = vrdval(p, "", conv_slash, vec, arg_ptr);
234			va_end(arg_ptr);
235
236			return result;
237			}
238
239			// Parses /proc/diskstats
240			// 1 2 3 4 5 6(rd) 7 8 9 10(wr) 11 12 13 14
241			// 3 0 hda 51292 14441 841783 926052 25717 79650 843256 3029804 0 148459 3956933
242			// 3 1 hda1 0 0 0 0 <- ignore if only 4 fields
243			static int rdval_diskstats(const char* p, ullong *vec)
244			{
245			ullong rd = rd; // for compiler
246			int indexline = 0;
247			vec[0] = 0;
248			vec[1] = 0;
249			while (1) {
250			indexline++;
251			while (p == ' ' \|\| p == '\t') p++;
252			if (*p == '\0') break;
253			if (*p == '\n') {
254			indexline = 0;
255			p++;
256			continue;
257			}
258			if (indexline == 6) {
259			rd = strtoull(p, NULL, 10);
260			} else if (indexline == 10) {
261			vec[0] += rd; // TODO: *sectorsize (don't know how to find out sectorsize)
262			vec[1] += strtoull(p, NULL, 10);
263			while (p != '\n' && p != '\0') p++;
264			continue;
265			}
266			while (*p > ' ') p++; // skip over value
267			}
268			return 0;
269			}
270
271			static void scale(ullong ul)
272			{
273			char buf[5];
274
275			/* see http://en.wikipedia.org/wiki/Tera */
276			smart_ulltoa4(ul, buf, " kmgtpezy");
277			buf[4] = '\0';
278			put(buf);
279			}
280
281
282			#define S_STAT(a) \
283			typedef struct a { \
284			struct s_stat *next; \
285			void (collect)(struct a s); \
286			const char *label;
287			#define S_STAT_END(a) } a;
288
289			S_STAT(s_stat)
290			S_STAT_END(s_stat)
291
292			static void collect_literal(s_stat *s UNUSED_PARAM)
293			{
294			}
295
296			static s_stat* init_literal(void)
297			{
298			s_stat s = xzalloc(sizeof(s));
299			s->collect = collect_literal;
300			return (s_stat*)s;
301			}
302
303			static s_stat* init_delay(const char *param)
304			{
305			delta = strtoul(param, NULL, 0) * 1000; /* param can be "" */
306			deltanz = delta > 0 ? delta : 1;
307			need_seconds = (1000000%deltanz) != 0;
308			return NULL;
309			}
310
311			static s_stat* init_cr(const char *param UNUSED_PARAM)
312			{
313			final_str = "\r";
314			return (s_stat*)0;
315			}
316
317
318			// user nice system idle iowait irq softirq (last 3 only in 2.6)
319			//cpu 649369 0 341297 4336769 11640 7122 1183
320			//cpuN 649369 0 341297 4336769 11640 7122 1183
321			enum { CPU_FIELDCNT = 7 };
322			S_STAT(cpu_stat)
323			ullong old[CPU_FIELDCNT];
324			int bar_sz;
325			char *bar;
326			S_STAT_END(cpu_stat)
327
328
329			static void collect_cpu(cpu_stat *s)
330			{
331			ullong data[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
332			unsigned frac[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
333			ullong all = 0;
334			int norm_all = 0;
335			int bar_sz = s->bar_sz;
336			char *bar = s->bar;
337			int i;
338
339			if (rdval(get_file(&proc_stat), "cpu ", data, 1, 2, 3, 4, 5, 6, 7)) {
340			put_question_marks(bar_sz);
341			return;
342			}
343
344			for (i = 0; i < CPU_FIELDCNT; i++) {
345			ullong old = s->old[i];
346			if (data[i] < old) old = data[i]; //sanitize
347			s->old[i] = data[i];
348			all += (data[i] -= old);
349			}
350
351			if (all) {
352			for (i = 0; i < CPU_FIELDCNT; i++) {
353			ullong t = bar_sz * data[i];
354			norm_all += data[i] = t / all;
355			frac[i] = t % all;
356			}
357
358			while (norm_all < bar_sz) {
359			unsigned max = frac[0];
360			int pos = 0;
361			for (i = 1; i < CPU_FIELDCNT; i++) {
362			if (frac[i] > max) max = frac[i], pos = i;
363			}
364			frac[pos] = 0; //avoid bumping up same value twice
365			data[pos]++;
366			norm_all++;
367			}
368
369			memset(bar, '.', bar_sz);
370			memset(bar, 'S', data[2]); bar += data[2]; //sys
371			memset(bar, 'U', data[0]); bar += data[0]; //usr
372			memset(bar, 'N', data[1]); bar += data[1]; //nice
373			memset(bar, 'D', data[4]); bar += data[4]; //iowait
374			memset(bar, 'I', data[5]); bar += data[5]; //irq
375			memset(bar, 'i', data[6]); bar += data[6]; //softirq
376			} else {
377			memset(bar, '?', bar_sz);
378			}
379			put(s->bar);
380			}
381
382
383			static s_stat* init_cpu(const char *param)
384			{
385			int sz;
386			cpu_stat s = xzalloc(sizeof(s));
387			s->collect = collect_cpu;
388			sz = strtoul(param, NULL, 0); /* param can be "" */
389			if (sz < 10) sz = 10;
390			if (sz > 1000) sz = 1000;
391			s->bar = xzalloc(sz+1);
392			/s->bar[sz] = '\0'; - xzalloc did it /
393			s->bar_sz = sz;
394			return (s_stat*)s;
395			}
396
397
398			S_STAT(int_stat)
399			ullong old;
400			int no;
401			S_STAT_END(int_stat)
402
403			static void collect_int(int_stat *s)
404			{
405			ullong data[1];
406			ullong old;
407
408			if (rdval(get_file(&proc_stat), "intr", data, s->no)) {
409			put_question_marks(4);
410			return;
411			}
412
413			old = s->old;
414			if (data[0] < old) old = data[0]; //sanitize
415			s->old = data[0];
416			scale(data[0] - old);
417			}
418
419			static s_stat* init_int(const char *param)
420			{
421			int_stat s = xzalloc(sizeof(s));
422			s->collect = collect_int;
423			if (param[0] == '\0') {
424			s->no = 1;
425			} else {
426			int n = xatoi_u(param);
427			s->no = n + 2;
428			}
429			return (s_stat*)s;
430			}
431
432
433			S_STAT(ctx_stat)
434			ullong old;
435			S_STAT_END(ctx_stat)
436
437			static void collect_ctx(ctx_stat *s)
438			{
439			ullong data[1];
440			ullong old;
441
442			if (rdval(get_file(&proc_stat), "ctxt", data, 1)) {
443			put_question_marks(4);
444			return;
445			}
446
447			old = s->old;
448			if (data[0] < old) old = data[0]; //sanitize
449			s->old = data[0];
450			scale(data[0] - old);
451			}
452
453			static s_stat* init_ctx(const char *param UNUSED_PARAM)
454			{
455			ctx_stat s = xzalloc(sizeof(s));
456			s->collect = collect_ctx;
457			return (s_stat*)s;
458			}
459
460
461			S_STAT(blk_stat)
462			const char* lookfor;
463			ullong old[2];
464			S_STAT_END(blk_stat)
465
466			static void collect_blk(blk_stat *s)
467			{
468			ullong data[2];
469			int i;
470
471			if (is26) {
472			i = rdval_diskstats(get_file(&proc_diskstats), data);
473			} else {
474			i = rdval(get_file(&proc_stat), s->lookfor, data, 1, 2);
475			// Linux 2.4 reports bio in Kbytes, convert to sectors:
476			data[0] *= 2;
477			data[1] *= 2;
478			}
479			if (i) {
480			put_question_marks(9);
481			return;
482			}
483
484			for (i=0; i<2; i++) {
485			ullong old = s->old[i];
486			if (data[i] < old) old = data[i]; //sanitize
487			s->old[i] = data[i];
488			data[i] -= old;
489			}
490			scale(data[0]512); // TODO: sectorsize
491			put_c(' ');
492			scale(data[1]*512);
493			}
494
495			static s_stat* init_blk(const char *param UNUSED_PARAM)
496			{
497			blk_stat s = xzalloc(sizeof(s));
498			s->collect = collect_blk;
499			s->lookfor = "page";
500			return (s_stat*)s;
501			}
502
503
504			S_STAT(fork_stat)
505			ullong old;
506			S_STAT_END(fork_stat)
507
508			static void collect_thread_nr(fork_stat *s UNUSED_PARAM)
509			{
510			ullong data[1];
511
512			if (rdval_loadavg(get_file(&proc_loadavg), data, 4)) {
513			put_question_marks(4);
514			return;
515			}
516			scale(data[0]);
517			}
518
519			static void collect_fork(fork_stat *s)
520			{
521			ullong data[1];
522			ullong old;
523
524			if (rdval(get_file(&proc_stat), "processes", data, 1)) {
525			put_question_marks(4);
526			return;
527			}
528
529			old = s->old;
530			if (data[0] < old) old = data[0]; //sanitize
531			s->old = data[0];
532			scale(data[0] - old);
533			}
534
535			static s_stat* init_fork(const char *param)
536			{
537			fork_stat s = xzalloc(sizeof(s));
538			if (*param == 'n') {
539			s->collect = collect_thread_nr;
540			} else {
541			s->collect = collect_fork;
542			}
543			return (s_stat*)s;
544			}
545
546
547			S_STAT(if_stat)
548			ullong old[4];
549			const char *device;
550			char *device_colon;
551			S_STAT_END(if_stat)
552
553			static void collect_if(if_stat *s)
554			{
555			ullong data[4];
556			int i;
557
558			if (rdval(get_file(&proc_net_dev), s->device_colon, data, 1, 3, 9, 11)) {
559			put_question_marks(10);
560			return;
561			}
562
563			for (i=0; i<4; i++) {
564			ullong old = s->old[i];
565			if (data[i] < old) old = data[i]; //sanitize
566			s->old[i] = data[i];
567			data[i] -= old;
568			}
569			put_c(data[1] ? '*' : ' ');
570			scale(data[0]);
571			put_c(data[3] ? '*' : ' ');
572			scale(data[2]);
573			}
574
575			static s_stat* init_if(const char *device)
576			{
577			if_stat s = xzalloc(sizeof(s));
578
579			if (!device \|\| !device[0])
580			bb_show_usage();
581			s->collect = collect_if;
582
583			s->device = device;
584			s->device_colon = xasprintf("%s:", device);
585			return (s_stat*)s;
586			}
587
588
589			S_STAT(mem_stat)
590			char opt;
591			S_STAT_END(mem_stat)
592
593			// "Memory" value should not include any caches.
594			// IOW: neither "ls -laR /" nor heavy read/write activity
595			// should affect it. We'd like to also include any
596			// long-term allocated kernel-side mem, but it is hard
597			// to figure out. For now, bufs, cached & slab are
598			// counted as "free" memory
599			//2.6.16:
600			//MemTotal: 773280 kB
601			//MemFree: 25912 kB - genuinely free
602			//Buffers: 320672 kB - cache
603			//Cached: 146396 kB - cache
604			//SwapCached: 0 kB
605			//Active: 183064 kB
606			//Inactive: 356892 kB
607			//HighTotal: 0 kB
608			//HighFree: 0 kB
609			//LowTotal: 773280 kB
610			//LowFree: 25912 kB
611			//SwapTotal: 131064 kB
612			//SwapFree: 131064 kB
613			//Dirty: 48 kB
614			//Writeback: 0 kB
615			//Mapped: 96620 kB
616			//Slab: 200668 kB - takes 7 Mb on my box fresh after boot,
617			// but includes dentries and inodes
618			// (== can take arbitrary amount of mem)
619			//CommitLimit: 517704 kB
620			//Committed_AS: 236776 kB
621			//PageTables: 1248 kB
622			//VmallocTotal: 516052 kB
623			//VmallocUsed: 3852 kB
624			//VmallocChunk: 512096 kB
625			//HugePages_Total: 0
626			//HugePages_Free: 0
627			//Hugepagesize: 4096 kB
628			static void collect_mem(mem_stat *s)
629			{
630			ullong m_total = 0;
631			ullong m_free = 0;
632			ullong m_bufs = 0;
633			ullong m_cached = 0;
634			ullong m_slab = 0;
635
636			if (rdval(get_file(&proc_meminfo), "MemTotal:", &m_total, 1)) {
637			put_question_marks(4);
638			return;
639			}
640			if (s->opt == 't') {
641			scale(m_total << 10);
642			return;
643			}
644
645			if (rdval(proc_meminfo.file, "MemFree:", &m_free , 1)
646			\|\| rdval(proc_meminfo.file, "Buffers:", &m_bufs , 1)
647			\|\| rdval(proc_meminfo.file, "Cached:", &m_cached, 1)
648			\|\| rdval(proc_meminfo.file, "Slab:", &m_slab , 1)
649			) {
650			put_question_marks(4);
651			return;
652			}
653
654			m_free += m_bufs + m_cached + m_slab;
655			switch (s->opt) {
656			case 'f':
657			scale(m_free << 10); break;
658			default:
659			scale((m_total - m_free) << 10); break;
660			}
661			}
662
663			static s_stat* init_mem(const char *param)
664			{
665			mem_stat s = xzalloc(sizeof(s));
666			s->collect = collect_mem;
667			s->opt = param[0];
668			return (s_stat*)s;
669			}
670
671
672			S_STAT(swp_stat)
673			S_STAT_END(swp_stat)
674
675			static void collect_swp(swp_stat *s UNUSED_PARAM)
676			{
677			ullong s_total[1];
678			ullong s_free[1];
679			if (rdval(get_file(&proc_meminfo), "SwapTotal:", s_total, 1)
680			\|\| rdval(proc_meminfo.file, "SwapFree:" , s_free, 1)
681			) {
682			put_question_marks(4);
683			return;
684			}
685			scale((s_total[0]-s_free[0]) << 10);
686			}
687
688			static s_stat* init_swp(const char *param UNUSED_PARAM)
689			{
690			swp_stat s = xzalloc(sizeof(s));
691			s->collect = collect_swp;
692			return (s_stat*)s;
693			}
694
695
696			S_STAT(fd_stat)
697			S_STAT_END(fd_stat)
698
699			static void collect_fd(fd_stat *s UNUSED_PARAM)
700			{
701			ullong data[2];
702
703			if (rdval(get_file(&proc_sys_fs_filenr), "", data, 1, 2)) {
704			put_question_marks(4);
705			return;
706			}
707
708			scale(data[0] - data[1]);
709			}
710
711			static s_stat* init_fd(const char *param UNUSED_PARAM)
712			{
713			fd_stat s = xzalloc(sizeof(s));
714			s->collect = collect_fd;
715			return (s_stat*)s;
716			}
717
718
719			S_STAT(time_stat)
720			int prec;
721			int scale;
722			S_STAT_END(time_stat)
723
724			static void collect_time(time_stat *s)
725			{
726			char buf[sizeof("12:34:56.123456")];
727			struct tm* tm;
728			int us = tv.tv_usec + s->scale/2;
729			time_t t = tv.tv_sec;
730
731			if (us >= 1000000) {
732			t++;
733			us -= 1000000;
734			}
735			tm = localtime(&t);
736
737			sprintf(buf, "%02d:%02d:%02d", tm->tm_hour, tm->tm_min, tm->tm_sec);
738			if (s->prec)
739			sprintf(buf+8, ".%0*d", s->prec, us / s->scale);
740			put(buf);
741			}
742
743			static s_stat* init_time(const char *param)
744			{
745			int prec;
746			time_stat s = xzalloc(sizeof(s));
747
748			s->collect = collect_time;
749			prec = param[0] - '0';
750			if (prec < 0) prec = 0;
751			else if (prec > 6) prec = 6;
752			s->prec = prec;
753			s->scale = 1;
754			while (prec++ < 6)
755			s->scale *= 10;
756			return (s_stat*)s;
757			}
758
759			static void collect_info(s_stat *s)
760			{
761			gen ^= 1;
762			while (s) {
763			put(s->label);
764			s->collect(s);
765			s = s->next;
766			}
767			}
768
769
770			typedef s_stat* init_func(const char *param);
771
772			static const char options[] ALIGN1 = "ncmsfixptbdr";
773			static init_func *const init_functions[] = {
774			init_if,
775			init_cpu,
776			init_mem,
777			init_swp,
778			init_fd,
779			init_int,
780			init_ctx,
781			init_fork,
782			init_time,
783			init_blk,
784			init_delay,
785			init_cr
786			};
787
788			int nmeter_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
789			int nmeter_main(int argc, char **argv)
790			{
791			char buf[32];
792			s_stat *first = NULL;
793			s_stat *last = NULL;
794			s_stat *s;
795			char cur, prev;
796
797			INIT_G();
798
799			xchdir("/proc");
800
801			if (argc != 2)
802			bb_show_usage();
803
804			if (open_read_close("version", buf, sizeof(buf)-1) > 0) {
805			buf[sizeof(buf)-1] = '\0';
806			is26 = (strstr(buf, " 2.4.") == NULL);
807			}
808
809			// Can use argv[1] directly, but this will mess up
810			// parameters as seen by e.g. ps. Making a copy...
811			cur = xstrdup(argv[1]);
812			while (1) {
813			char param, p;
814			prev = cur;
815			again:
816			cur = strchr(cur, '%');
817			if (!cur)
818			break;
819			if (cur[1] == '%') { // %%
820			overlapping_strcpy(cur, cur + 1);
821			cur++;
822			goto again;
823			}
824			*cur++ = '\0'; // overwrite %
825			if (cur[0] == '[') {
826			// format: %[foptstring]
827			cur++;
828			p = strchr(options, cur[0]);
829			param = cur+1;
830			while (cur[0] != ']') {
831			if (!cur[0])
832			bb_show_usage();
833			cur++;
834			}
835			*cur++ = '\0'; // overwrite [
836			} else {
837			// format: %NNNNNNf
838			param = cur;
839			while (cur[0] >= '0' && cur[0] <= '9')
840			cur++;
841			if (!cur[0])
842			bb_show_usage();
843			p = strchr(options, cur[0]);
844			*cur++ = '\0'; // overwrite format char
845			}
846			if (!p)
847			bb_show_usage();
848			s = init_functions[p-options](param);
849			if (s) {
850			s->label = prev;
851			/s->next = NULL; - all initXXX funcs use xzalloc /
852			if (!first)
853			first = s;
854			else
855			last->next = s;
856			last = s;
857			} else {
858			// %NNNNd or %r option. remove it from string
859			strcpy(prev + strlen(prev), cur);
860			cur = prev;
861			}
862			}
863			if (prev[0]) {
864			s = init_literal();
865			s->label = prev;
866			/s->next = NULL; - all initXXX funcs use xzalloc /
867			if (!first)
868			first = s;
869			else
870			last->next = s;
871			last = s;
872			}
873
874			// Generate first samples but do not print them, they're bogus
875			collect_info(first);
876			reset_outbuf();
877			if (delta >= 0) {
878			gettimeofday(&tv, NULL);
879			usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
880			}
881
882			while (1) {
883			gettimeofday(&tv, NULL);
884			collect_info(first);
885			put(final_str);
886			print_outbuf();
887
888			// Negative delta -> no usleep at all
889			// This will hog the CPU but you can have REALLY GOOD
890			// time resolution ;)
891			// TODO: detect and avoid useless updates
892			// (like: nothing happens except time)
893			if (delta >= 0) {
894			int rem;
895			// can be commented out, will sacrifice sleep time precision a bit
896			gettimeofday(&tv, NULL);
897			if (need_seconds)
898			rem = delta - ((ullong)tv.tv_sec*1000000 + tv.tv_usec) % deltanz;
899			else
900			rem = delta - tv.tv_usec%deltanz;
901			// Sometimes kernel wakes us up just a tiny bit earlier than asked
902			// Do not go to very short sleep in this case
903			if (rem < delta/128) {
904			rem += delta;
905			}
906			usleep(rem);
907			}
908			}
909
910			/return 0;/
911			}