add fmt_human and fmt_humank

CHANGES

@@ -11,6 +11,7 @@
   fix typos in several man pages (Hynek Schlawack)
   add stralloc versions of textcode API (Kai Ruemmler)
   add html to textcode ('<' to '&lt;' etc)
+  add fmt_human and fmt_humank (format numbers ala ls -H/-h)
 
 0.14:
   avoid bus errors in byte_copy

fmt.h

@@ -69,4 +69,10 @@ unsigned int fmt_pad(char* dest,const char* src,unsigned int srclen,unsigned int
  * characters written. */
 unsigned int fmt_fill(char* dest,unsigned int srclen,unsigned int padlen,unsigned int maxlen);
 
+/* 1 -> "1", 4900 -> "4.9k", 2300000 -> "2.3M" */
+unsigned int fmt_human(char* dest,unsigned long long l);
+
+/* 1 -> "1", 4900 -> "4.8k", 2300000 -> "2.2M" */
+unsigned int fmt_humank(char* dest,unsigned long long l);
+
 #endif

fmt/fmt_human.c

@@ -0,0 +1,26 @@
+#include "fmt.h"
+
+unsigned int fmt_human(char* dest,unsigned long long l) {
+  char unit;
+  int i;
+  if (l<1000) return fmt_ulong(dest,l);
+  if (l>1000000000000ull) {
+    l=(l+50000000000ull)/100000000000ull;
+    unit='T';
+  } else if (l>1000000000) {
+    l=(l+50000000)/100000000;
+    unit='G';
+  } else if (l>1000000) {
+    l=(l+50000)/100000;
+    unit='M';
+  } else if (l>1000) {
+    l=(l+50)/100;
+    unit='k';
+  }
+  if (!dest) return fmt_ulong(0,l)+2;
+  i=fmt_ulong(dest,l/10);
+  dest[i]='.';
+  dest[i+1]=(l%10)+'0';
+  dest[i+2]=unit;
+  return i+3;
+}

fmt/fmt_humank.c

@@ -0,0 +1,26 @@
+#include "fmt.h"
+
+unsigned int fmt_humank(char* dest,unsigned long long l) {
+  char unit;
+  int i;
+  if (l<1000) return fmt_ulong(dest,l);
+  if (l>1024*1024*1024*1024ull) {
+    l=(l+(1024*1024*1024*1024ull/20))/(1024*1024*1024*1024ull/10);
+    unit='T';
+  } else if (l>1024*1024*1024) {
+    l=(l+(1024*1024*1024/20))/(1024*1024*1024/10);
+    unit='G';
+  } else if (l>1024*1024) {
+    l=(l+(1024*1024/20))/(1024*1024/10);
+    unit='M';
+  } else if (l>1024) {
+    l=(l+(1024/20))/(1024/10);
+    unit='k';
+  }
+  if (!dest) return fmt_ulong(0,l)+2;
+  i=fmt_ulong(dest,l/10);
+  dest[i]='.';
+  dest[i+1]=(l%10)+'0';
+  dest[i+2]=unit;
+  return i+3;
+}