ps: fix overflow in USER and VSZ columns

function                                             old     new   delta
smart_ulltoa4                                          -     280    +280
smart_ulltoa5                                        283     408    +125
ulltoa6_and_space                                      -      25     +25
scale                                                 28      38     +10
bbunpack                                             358     366      +8
ps_main                                              259     261      +2
glob3                                                 35      37      +2
fill_bounds                                          172     174      +2
process_stdin                                        456     446     -10
smart_ulltoa6                                        406       -    -406
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 6/1 up/down: 454/-416)           Total: 38 bytes

1 files changed, 61 insertions, 8 deletions

diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 6d8eac4b6..6d50bf9bc 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -282,10 +282,10 @@ void xsetenv(const char *key, const char *value)
                 bb_error_msg_and_die(bb_msg_memory_exhausted);
 }
 
-// Converts unsigned long long value into compact 4-char
-// representation. Examples: "1234", "1.2k", " 27M", "123T"
-// Fifth char is always '\0'
-void smart_ulltoa5(unsigned long long ul, char buf[5])
+/* Converts unsigned long long value into compact 4-char
+ * representation. Examples: "1234", "1.2k", " 27M", "123T"
+ * String is not terminated (buf[4] is untouched) */
+void smart_ulltoa4(unsigned long long ul, char buf[5], const char *scale)
 {
         const char *fmt;
         char c;
@@ -327,13 +327,66 @@ void smart_ulltoa5(unsigned long long ul, char buf[5])
                         buf[1] = '.';
                 }
                 buf[2] = "0123456789"[v];
-                // see http://en.wikipedia.org/wiki/Tera
-                // (small letters stand out better versus numbers)
-                buf[3] = " kmgtpezy"[idx];
+                buf[3] = scale[idx]; /* typically scale = " kmgt..." */
         }
-        buf[4] = '\0';
 }
 
+/* Converts unsigned long long value into compact 5-char representation.
+ * String is not terminated (buf[5] is untouched) */
+void smart_ulltoa5(unsigned long long ul, char buf[6], const char *scale)
+{
+        const char *fmt;
+        char c;
+        unsigned v, u, idx = 0;
+
+        if (ul > 99999) { // do not scale if 99999 or less
+                ul *= 10;
+                do {
+                        ul /= 1024;
+                        idx++;
+                } while (ul >= 100000);
+        }
+        v = ul; // ullong divisions are expensive, avoid them
+
+        fmt = " 123456789";
+        u = v / 10;
+        v = v % 10;
+        if (!idx) {
+                // 99999 or less: use "12345" format
+                // u is value/10, v is last digit
+                c = buf[0] = " 123456789"[u/1000];
+                if (c != ' ') fmt = "0123456789";
+                c = buf[1] = fmt[u/100%10];
+                if (c != ' ') fmt = "0123456789";
+                c = buf[2] = fmt[u/10%10];
+                if (c != ' ') fmt = "0123456789";
+                buf[3] = fmt[u%10];
+                buf[4] = "0123456789"[v];
+        } else {
+                // value has been scaled into 0..9999.9 range
+                // u is value, v is 1/10ths (allows for 92.1M format)
+                if (u >= 100) {
+                        // value is >= 100: use "1234M', " 123M" formats
+                        c = buf[0] = " 123456789"[u/1000];
+                        if (c != ' ') fmt = "0123456789";
+                        c = buf[1] = fmt[u/100%10];
+                        if (c != ' ') fmt = "0123456789";
+                        v = u % 10;
+                        u = u / 10;
+                        buf[2] = fmt[u%10];
+                } else {
+                        // value is < 100: use "92.1M" format
+                        c = buf[0] = " 123456789"[u/10];
+                        if (c != ' ') fmt = "0123456789";
+                        buf[1] = fmt[u%10];
+                        buf[2] = '.';
+                }
+                buf[3] = "0123456789"[v];
+                buf[4] = scale[idx]; /* typically scale = " kmgt..." */
+        }
+}
+
+
 // Convert unsigned integer to ascii, writing into supplied buffer.
 // A truncated result contains the first few digits of the result ala strncpy.
 // Returns a pointer past last generated digit, does _not_ store NUL.