Add gettokens() string function

src/gettokens.c

@@ -0,0 +1,58 @@
+#include <string.h>
+#include "ucore/string.h"
+
+//tokenize string, and exclude the quotes
+static char *qtoken(char *s, const char *sep)
+{
+    int inquote = 0;
+    char *t = s;
+    while (*t != 0 && (inquote || strchr(sep, *t) == NULL)) {
+        if (*t != '"') {
+            *s++ = *t++;
+            continue;
+        }
+
+        if (!inquote) {
+            inquote = 1;
+            t++;
+            continue;
+        }
+
+        if (t[1] != '"') {
+            t++;
+            inquote = 0;
+            continue;
+        }
+        //double quotes, merged to 1 quote 
+        t++;
+        *s++ = *t++;
+    }
+
+    if (*s != 0) {
+        *s = 0;
+        if (t == s) {
+            t++;
+        }
+    }
+   
+   return t; 
+}
+
+int gettokens(char *str, char **args, int maxargs, const char *sep)
+{
+    int nargs;
+
+    for (nargs = 0; nargs < maxargs; nargs++) {
+        while (*str != 0 && strchr(sep, *str) != NULL) {
+            *str++ = 0;
+        }
+        if (*str == 0) {
+            break;
+        }
+        args[nargs] = str;
+        str = qtoken(str, sep);
+    }
+
+    return nargs;
+}
+