usr: libc: Add strtok()

Ported from OpenBSD

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

2 files changed, 84 insertions, 0 deletions

diff --git a/lib/libc/include/string.h b/lib/libc/include/string.h
index 4ac384b..8ba2b4e 100644
--- a/lib/libc/include/string.h
+++ b/lib/libc/include/string.h
@@ -34,6 +34,8 @@
 #include <stdint.h>
 
 size_t strlen(const char *s);
+char *strtok(char *s, const char *delim);
+
 void *memset(void *dst, int c, size_t n);
 int memcmp(const void *s1, const void *s2, size_t n);
 
diff --git a/lib/libc/src/string/strtok.c b/lib/libc/src/string/strtok.c
new file mode 100644
index 0000000..f01dcd6
--- /dev/null
+++ b/lib/libc/src/string/strtok.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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 Hyra 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 <string.h>
+
+static char *
+__strtok(char *s, const char *delim, char **last)
+{
+    const char *spanp;
+    char *tok;
+    int c, sc;
+
+    if (s == NULL && (s = *last) == NULL) {
+        return NULL;
+    }
+
+cont:
+    c = *s++;
+    for (spanp = delim; (sc = *spanp++) != 0;) {
+        if (c == sc)
+            goto cont;
+    }
+
+    if (c == 0) {
+        *last = NULL;
+        return NULL;
+    }
+
+    tok = s - 1;
+
+    /* Scan tokens */
+    for (;;) {
+        c = *s++;
+        spanp = delim;
+        do {
+            if ((sc = *spanp++) == c) {
+                if (c == 0)
+                    s = NULL;
+                else
+                    s[-1] = '\0';
+                *last = s;
+                return (tok);
+            }
+        } while (sc != 0);
+    }
+
+    __builtin_unreachable();
+}
+
+char *
+strtok(char *s, const char *delim)
+{
+    static char *last;
+
+    return __strtok(s, delim, &last);
+}