From cf13cb256bd7c58a3df4ed899d3765ebd1a0a8c5 Mon Sep 17 00:00:00 2001
From: David Anderson <davea@ssl.berkeley.edu>
Date: Tue, 11 Aug 2015 14:18:06 -0700
Subject: [PATCH] lib: add function for formatting numbers w/ digit grouping

---
 lib/str_util.cpp | 31 +++++++++++++++++++++++++++++++
 lib/str_util.h   |  1 +
 2 files changed, 32 insertions(+)

diff --git a/lib/str_util.cpp b/lib/str_util.cpp
index e0f78b97ec..ad57e6151e 100644
--- a/lib/str_util.cpp
+++ b/lib/str_util.cpp
@@ -756,3 +756,34 @@ vector<string> split(string s, char delim) {
     }
     return result;
 }
+
+char *comma_print(unsigned long n) {
+    static char comma = 0;
+    static char retbuf[30];
+    char *p = &retbuf[sizeof(retbuf)-1];
+    int i = 0;
+
+    if (!comma) {
+        struct lconv *lcp = localeconv();
+        if (lcp) {
+            if (lcp->thousands_sep != NULL && *lcp->thousands_sep) {
+                comma = *lcp->thousands_sep;
+            } else {
+                comma = ',';
+            }
+        }
+    }
+
+    *p = 0;
+
+    do {
+        if (i%3 == 0 && i != 0) {
+            *--p = comma;
+        }
+        *--p = '0' + n % 10;
+        n /= 10;
+        i++;
+    } while (n);
+
+    return p;
+}
diff --git a/lib/str_util.h b/lib/str_util.h
index ea2eec7f29..e890b59a29 100644
--- a/lib/str_util.h
+++ b/lib/str_util.h
@@ -101,4 +101,5 @@ extern const char* batch_state_string(int state);
 extern void strip_translation(char* p);
 
 extern std::vector<std::string> split(std::string, char delim);
+extern char* comma_print(unsigned long);
 #endif