Create a simple custom string library.

src/libk/string.c

@@ -0,0 +1,105 @@
+#include <stdbool.h>
+#include <libc/string.h>
+#include <libk/assert.h>
+#include <kernel/kmalloc.h>
+#include "string.h"
+
+string *string_split(const_string str, const_string delimiter)
+{
+  size_t length = strlen(str);
+  string *parts = kmalloc(length + 5);
+  string substr;
+  int count = 0;
+
+  for (size_t i = 0; i < strlen(str); i++)
+  {
+    substr = string_substring_range(str, i, length);
+
+    int pos = string_find(substr, delimiter);
+    kfree(substr);
+
+    // TODO: This a hackish and buggy in some cases. (For example: ',,,,' with ',')
+    if (pos == -1)
+    {
+      pos = length;
+    }
+
+    parts[count++] = string_substring(str, i, pos);
+
+    i += pos;
+  }
+
+  parts[count] = NULL;
+
+  return parts;
+}
+
+string string_normalize_spaces(const_string str)
+{
+  string result = kmalloc(string_length(str));
+  char c = 0;
+  int r = 0;
+
+  for (size_t i = 0; i < string_length(result); i++)
+  {
+    while (c == ' ') //replaces two or more spaces by a single space
+    {
+      c = str[i++];
+      if (c != ' ')
+        result[r++] = c;
+    }
+  }
+
+  return result;
+}
+
+// TODO: Should use a better algorithm here.
+int string_find(const_string str, const_string needle)
+{
+  for (size_t i = 0; i < strlen(str); i++)
+  {
+    bool found = true;
+
+    for (size_t j = 0; j < strlen(needle); j++)
+    {
+      if (str[i] != needle[j])
+      {
+        found = false;
+
+        break;
+      }
+    }
+
+    if (found)
+    {
+      return i;
+    }
+  }
+
+  return -1;
+}
+
+string string_substring(const_string str, int start, int length)
+{
+  ASSERT(length > 0);
+
+  string substr = kmalloc(length + 1);
+
+  memcpy(substr, &str[start], length);
+
+  substr[length] = '\0';
+
+  return substr;
+}
+
+string string_substring_range(const_string str, int start, int end)
+{
+  ASSERT(start < end);
+
+  return string_substring(str, start, end - start);
+}
+
+size_t string_length(const_string str)
+{
+  return strlen(str);
+}

src/libk/string.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stddef.h>
+
+typedef char *string;
+typedef const char *const_string;
+
+string *string_split(const_string str, const_string delimiter);
+string string_normalize_spaces(const_string str);
+int string_find(const_string str, const_string needle);
+string string_substring(const_string str, int start, int length);
+string string_substring_range(const_string str, int start, int end);
+size_t string_length(const_string str);