src/utils.h: adding rtrim,ltrim,trim functions.

src/utils.cpp

@@ -21,6 +21,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
+#include <algorithm>
+#include <cctype>
 #include "utils.h"
 
 std::vector<std::string> strsplit(const std::string& str, const std::string& delim) {
@@ -41,3 +43,22 @@ void strtolower(std::string& str) {
 
 	std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c){ return std::tolower(c); });
 }
+
+std::string& ltrim(std::string& str)
+{
+  auto it = std::find_if(str.begin(), str.end(), [](char ch){ return !std::isspace(ch); });
+  str.erase(str.begin(), it);
+  return str;
+}
+
+std::string& rtrim(std::string& str)
+{
+  auto it = std::find_if(str.rbegin(), str.rend(), [](char ch){ return !std::isspace(ch); });
+  str.erase(it.base(), str.end());
+  return str;
+}
+
+
+std::string& trim(std::string& str) {
+	return ltrim(rtrim(str));
+}