file reading, tarfs directory listing

1 files changed, 21 insertions, 0 deletions

diff --git a/include/mercury/kernel/utility.hpp b/include/mercury/kernel/utility.hpp
index f12101a..1648e67 100644
--- a/include/mercury/kernel/utility.hpp
+++ b/include/mercury/kernel/utility.hpp
@@ -29,6 +29,27 @@ namespace mercury::kernel::utility {
     return len;
   }
 
+  //if c appears in str, this returns the index of the last time it appears.
+  //otherwise, this returns len.
+  static inline unsigned find_last(const char *str, unsigned len, char c) {
+    for (unsigned i = len; i > 0; --i)
+      if (str[i - 1] == c)
+        return i - 1;
+    return len;
+  }
+
+  //str1 starts with str2
+  static inline bool starts_with(
+    const char *str1, unsigned str1_len, const char *str2, unsigned str2_len
+  ) {
+    if (str1_len < str2_len)
+      return false;
+    for (unsigned i = 0; i < str2_len; ++i)
+      if (str1[i] != str2[i])
+        return false;
+    return true;
+  }
+
   template <class value_t>
   struct list {