top: add -m ("memory") option

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/TODO b/TODO
index cd2aa0e..136aeb7 100644
--- a/TODO
+++ b/TODO
@@ -320,6 +320,29 @@
 
 Unicode work needed:
 
+Unicode support uses libc multibyte functions if LOCALE_SUPPORT is on
+(in this case, the code will also support many more encodings),
+or uses a limited subset of re-implemented multibyte functions
+which only understand "one byte == one char" and unicode.
+This is useful if you build against uclibc with locale support disabled.
+
+Unicode-dependent applets must call check_unicode_in_env() when they
+begin executing.
+
+Applet code may conditionalize on FEATURE_ASSUME_UNICODE
+in order to use more efficient code if unicode support is not requested.
+
+Available functions (if you need more, implement them in libbb/unicode.c
+so that they work without LOCALE_SUPPORT too):
+
+int bb_mbstrlen(str) - multibyte-aware strlen
+size_t mbstowcs(wdest, src, n)
+size_t wcstombs(dest, wsrc, n)
+size_t wcrtomb(str, wc, wstate)
+int iswspace(wc)
+int iswalnum(wc)
+int iswpunct(wc)
+
 Applets which only need to align columns on screen correctly:
 
 ls - already done, use source as an example
diff --git a/include/usage.h b/include/usage.h
index 036cf9d..907eb78 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -4566,7 +4566,7 @@
        "Defaults: SECS: 10, SIG: TERM." \
 
 #define top_trivial_usage \
-       "[-b] [-nCOUNT] [-dSECONDS]"
+       "[-b] [-nCOUNT] [-dSECONDS]" IF_FEATURE_TOPMEM(" [-m]")
 #define top_full_usage "\n\n" \
        "Provide a view of process activity in real time.\n" \
        "Read the status of all processes from /proc each SECONDS\n" \
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 17b8dd1..cab3eb7 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -147,15 +147,15 @@
 
 Special characters:
 
- "-"    A dash as the first char in a opt_complementary group forces
-        all arguments to be treated as options, even if they have
-        no leading dashes. Next char in this case can't be a digit (0-9),
-        use ':' or end of line. For example:
+ "-"    A group consisting of just a dash forces all arguments
+        to be treated as options, even if they have no leading dashes.
+        Next char in this case can't be a digit (0-9), use ':' or end of line.
+        Example:
 
-        opt_complementary = "-:w-x:x-w";
-        getopt32(argv, "wx");
+        opt_complementary = "-:w-x:x-w"; // "-w-x:x-w" would also work,
+        getopt32(argv, "wx");            // but is less readable
 
-        Allows any arguments to be given without a dash (./program w x)
+        This makes it possible to use options without a dash (./program w x)
         as well as with a dash (./program -x).
 
         NB: getopt32() will leak a small amount of memory if you use
diff --git a/procps/top.c b/procps/top.c
index 62b9c1e..92360a0 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -131,7 +131,8 @@
 	OPT_d = (1 << 0),
 	OPT_n = (1 << 1),
 	OPT_b = (1 << 2),
-	OPT_EOF = (1 << 3), /* pseudo: "we saw EOF in stdin" */
+	OPT_m = (1 << 3),
+	OPT_EOF = (1 << 4), /* pseudo: "we saw EOF in stdin" */
 };
 #define OPT_BATCH_MODE (option_mask32 & OPT_b)
 
@@ -348,29 +349,29 @@
 	jiffy_counts_t *p_jif, *p_prev_jif;
 	int i;
 
-#if ENABLE_FEATURE_TOP_SMP_CPU
+# if ENABLE_FEATURE_TOP_SMP_CPU
 	int n_cpu_lines;
-#endif
+# endif
 
 	/* using (unsigned) casts to make operations cheaper */
-#define  CALC_TOT_DIFF  ((unsigned)(p_jif->total - p_prev_jif->total) ? : 1)
+# define  CALC_TOT_DIFF  ((unsigned)(p_jif->total - p_prev_jif->total) ? : 1)
 
-#if ENABLE_FEATURE_TOP_DECIMALS
-#define CALC_STAT(xxx) char xxx[8]
-#define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
-#define FMT "%s"
-#else
-#define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
-#define SHOW_STAT(xxx) xxx
-#define FMT "%4u%% "
-#endif
+# if ENABLE_FEATURE_TOP_DECIMALS
+#  define CALC_STAT(xxx) char xxx[8]
+#  define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
+#  define FMT "%s"
+# else
+#  define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
+#  define SHOW_STAT(xxx) xxx
+#  define FMT "%4u%% "
+# endif
 
-#if !ENABLE_FEATURE_TOP_SMP_CPU
+# if !ENABLE_FEATURE_TOP_SMP_CPU
 	{
 		i = 1;
 		p_jif = &cur_jif;
 		p_prev_jif = &prev_jif;
-#else
+# else
 	/* Loop thru CPU(s) */
 	n_cpu_lines = smp_cpu_info ? num_cpus : 1;
 	if (n_cpu_lines > *lines_rem_p)
@@ -379,7 +380,7 @@
 	for (i = 0; i < n_cpu_lines; i++) {
 		p_jif = &cpu_jif[i];
 		p_prev_jif = &cpu_prev_jif[i];
-#endif
+# endif
 		total_diff = CALC_TOT_DIFF;
 
 		{ /* Need a block: CALC_STAT are declarations */
@@ -394,12 +395,12 @@
 
 			snprintf(scrbuf, scr_width,
 				/* Barely fits in 79 chars when in "decimals" mode. */
-#if ENABLE_FEATURE_TOP_SMP_CPU
+# if ENABLE_FEATURE_TOP_SMP_CPU
 				"CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
 				(smp_cpu_info ? utoa(i) : ""),
-#else
+# else
 				"CPU:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
-#endif
+# endif
 				SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
 				SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
 				/*, SHOW_STAT(steal) - what is this 'steal' thing? */
@@ -408,13 +409,13 @@
 			puts(scrbuf);
 		}
 	}
-#undef SHOW_STAT
-#undef CALC_STAT
-#undef FMT
+# undef SHOW_STAT
+# undef CALC_STAT
+# undef FMT
 	*lines_rem_p -= i;
 }
 #else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
-#define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
+# define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
 #endif
 
 static unsigned long display_header(int scr_width, int *lines_rem_p)
@@ -528,15 +529,15 @@
 	lines_rem--;
 
 #if ENABLE_FEATURE_TOP_DECIMALS
-#define UPSCALE 1000
-#define CALC_STAT(name, val) div_t name = div((val), 10)
-#define SHOW_STAT(name) name.quot, '0'+name.rem
-#define FMT "%3u.%c"
+# define UPSCALE 1000
+# define CALC_STAT(name, val) div_t name = div((val), 10)
+# define SHOW_STAT(name) name.quot, '0'+name.rem
+# define FMT "%3u.%c"
 #else
-#define UPSCALE 100
-#define CALC_STAT(name, val) unsigned name = (val)
-#define SHOW_STAT(name) name
-#define FMT "%4u%%"
+# define UPSCALE 100
+# define CALC_STAT(name, val) unsigned name = (val)
+# define SHOW_STAT(name) name
+# define FMT "%4u%%"
 #endif
 	/*
 	 * MEM% = s->vsz/MemTotal
@@ -646,9 +647,9 @@
 	tcsetattr_stdin_TCSANOW(&initial_settings);
 	if (ENABLE_FEATURE_CLEAN_UP) {
 		clearmems();
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 		free(prev_hist);
-#endif
+# endif
 	}
 }
 
@@ -895,7 +896,7 @@
 
 	pfd[0].fd = 0;
 	pfd[0].events = POLLIN;
-#endif /* FEATURE_USE_TERMIOS */
+#endif
 
 	INIT_G();
 
@@ -909,10 +910,15 @@
 #endif
 
 	/* all args are options; -n NUM */
-	opt_complementary = "-";
-	col = getopt32(argv, "d:n:b", &str_interval, &str_iterations);
+	opt_complementary = "-"; /* options can be specified w/o dash */
+	col = getopt32(argv, "d:n:b"IF_FEATURE_TOPMEM("m"), &str_interval, &str_iterations);
+#if ENABLE_FEATURE_TOPMEM
+	if (col & OPT_m) /* -m (busybox specific) */
+		scan_mask = TOPMEM_MASK;
+#endif
 	if (col & OPT_d) {
-		/* work around for "-d 1" -> "-d -1" done by getopt32 */
+		/* work around for "-d 1" -> "-d -1" done by getopt32
+		 * (opt_complementary == "-" does this) */
 		if (str_interval[0] == '-')
 			str_interval++;
 		/* Need to limit it to not overflow poll timeout */
@@ -934,7 +940,7 @@
 
 	bb_signals(BB_FATAL_SIGS, sig_catcher);
 	tcsetattr_stdin_TCSANOW(&new_settings);
-#endif /* FEATURE_USE_TERMIOS */
+#endif
 
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 	sort_function[0] = pcpu_sort;
@@ -942,7 +948,7 @@
 	sort_function[2] = time_sort;
 #else
 	sort_function[0] = mem_sort;
-#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
+#endif
 
 	while (1) {
 		procps_status_t *p = NULL;
@@ -956,7 +962,7 @@
 			sleep(interval);
 			continue;
 		}
-#endif /* FEATURE_USE_TERMIOS */
+#endif
 		if (col > LINE_BUF_SIZE-2) /* +2 bytes for '\n', NUL, */
 			col = LINE_BUF_SIZE-2;
 
@@ -1015,7 +1021,7 @@
 			qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
 #else
 			qsort(top, ntop, sizeof(top_status_t), (void*)(sort_function[0]));
-#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
+#endif
 		}
 #if ENABLE_FEATURE_TOPMEM
 		else { /* TOPMEM */
@@ -1058,12 +1064,12 @@
 			if (c == 'm') {
 				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 				sort_function[0] = mem_sort;
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 				sort_function[1] = pcpu_sort;
 				sort_function[2] = time_sort;
-#endif
+# endif
 			}
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
 			if (c == 'p') {
 				IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
 				sort_function[0] = pcpu_sort;
@@ -1076,7 +1082,7 @@
 				sort_function[1] = mem_sort;
 				sort_function[2] = pcpu_sort;
 			}
-#if ENABLE_FEATURE_TOPMEM
+#  if ENABLE_FEATURE_TOPMEM
 			if (c == 's') {
 				scan_mask = TOPMEM_MASK;
 				free(prev_hist);
@@ -1086,8 +1092,8 @@
 			}
 			if (c == 'r')
 				inverted ^= 1;
-#endif
-#if ENABLE_FEATURE_TOP_SMP_CPU
+#  endif
+#  if ENABLE_FEATURE_TOP_SMP_CPU
 			/* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
 			if (c == 'c' || c == '1') {
 				/* User wants to toggle per cpu <> aggregate */
@@ -1104,8 +1110,8 @@
 				smp_cpu_info = !smp_cpu_info;
 				get_jiffy_counts();
 			}
-#endif
-#endif
+#  endif
+# endif
 		}
 #endif /* FEATURE_USE_TERMIOS */
 	} /* end of "while (1)" */