kern: lib: Add strdup()

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 59 insertions, 0 deletions

diff --git a/src/sys/include/lib/string.h b/src/sys/include/lib/string.h
index 3da8b5f..e7c9905 100644
--- a/src/sys/include/lib/string.h
+++ b/src/sys/include/lib/string.h
@@ -68,6 +68,13 @@ int snprintf(char *s, size_t size, const char *fmt, ...);
  */
 char *itoa(int64_t value, char *buf, int base);
 
+/*
+ * Duplicate a string onto heap
+ *
+ * @s: String to duplicate
+ */
+char *strdup(const char *s);
+
 __END_DECLS
 
 #endif  /* !_LIB_STRING_H */
diff --git a/src/sys/lib/string/strdup.c b/src/sys/lib/string/strdup.c
new file mode 100644
index 0000000..297479e
--- /dev/null
+++ b/src/sys/lib/string/strdup.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <os/kalloc.h>
+#include <string.h>
+
+char *
+strdup(const char *s)
+{
+    size_t len;
+    char *new_str = NULL;
+
+    if (s == NULL) {
+        return NULL;
+    }
+
+    len = strlen(s);
+    new_str = kalloc(len + 1);
+    if (new_str == NULL) {
+        return NULL;
+    }
+
+    memcpy(new_str, s, len + 1);
+    return new_str;
+}