GUACAMOLE-1686: Add convenience function for converting integer to st…

…ring.

src/libguac/guacamole/string.h

@@ -29,6 +29,23 @@
 #include <stddef.h>
 #include <string.h>
 
+/**
+ * Convert the provided integer into a string, returning the number of
+ * characters written into the destination string, or a negative value if an
+ * error occurs.
+ *
+ * @param dest
+ *     The destination string to copy the data into. This need not be initialized
+ *     before calling this function - this function will allocate the memory.
+ *
+ * @param integer
+ *     The integer to convert to a string.
+ * 
+ * @return
+ *     The number of characters written into the dest string.
+ */
+size_t guac_itoa(char* restrict dest, int integer);
+
 /**
  * Copies a limited number of bytes from the given source string to the given
  * destination buffer. The resulting buffer will always be null-terminated,

src/libguac/string.c

@@ -22,6 +22,7 @@
 #include "guacamole/mem.h"
 
 #include <stddef.h>
+#include <stdio.h>
 #include <string.h>
 
 /**
@@ -44,6 +45,19 @@
  */
 #define REMAINING(n, length) (((n) < (length)) ? 0 : ((n) - (length)))
 
+size_t guac_itoa(char* restrict dest, int integer) {
+
+    /* Determine size of string. */
+    int str_size = snprintf(dest, 0, "%u", integer);
+
+    /* Allocate the memory. */
+    dest = guac_mem_alloc(str_size + 1);
+
+    /* Do the conversion and return. */
+    return snprintf(dest, str_size, "%u", integer);
+
+}
+
 size_t guac_strlcpy(char* restrict dest, const char* restrict src, size_t n) {
 
 #ifdef HAVE_STRLCPY