Espresso 0.0.2c

lib/espresso/kstring.c

@@ -0,0 +1,58 @@
+#include <stdlib.h>
+#include <types.h>
+#include <string.h>
+
+
+/*
+A custom standard for strings for use in the Espresso kernel.
+*/
+
+struct kstring {
+  size_t s_len;
+  char* data; /* NOT null-terminated */
+};
+
+/*
+if the length of initial_data is more than initial_len, only initial_len bytes will be copied.
+if the length of initial_data is less then initial_len, the rest of the bytes are zeroed.
+if initial_data is null, no data is copied and the string in set to zero.
+*/
+struct kstring* make_kstring(size_t initial_len, const char* initial_data)
+{
+  struct kstring* str = malloc(sizeof(struct kstring));
+
+  if (!str)
+  {
+    return NULL;
+  }
+
+  str->s_len = initial_len;
+  str->data = malloc(initial_len);
+
+  if (!str->data)
+  {
+    return NULL;
+  }
+  
+  memset(str->data, 0, initial_len);
+
+  if (initial_data)
+  {
+    size_t slen = strlen(initial_data);
+
+    if (slen < initial_len)
+    {
+      strncpy(str->data, initial_data, slen);
+    }
+    else if (slen > initial_len)
+    {
+      strncpy(str->data, initial_data, initial_len);
+    }
+    else
+    {
+      strcpy(str->data, initial_data);
+    }
+  }
+
+  return str;
+}