From 30a978beca03b02af601ed488c521778979b84da Mon Sep 17 00:00:00 2001
From: thetek <git@thetek.de>
Date: Wed, 15 Feb 2023 09:37:20 +0100
Subject: [PATCH] feat: (str) str_find, str_pos

---
 lib/inc/str.h |  3 +++
 lib/str.c     | 35 +++++++++++++++++++++++++++++++++++
 test/main.c   |  5 +++++
 3 files changed, 43 insertions(+)

diff --git a/lib/inc/str.h b/lib/inc/str.h
index 92d9c69..bfbed58 100644
--- a/lib/inc/str.h
+++ b/lib/inc/str.h
@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#include <sys/types.h>
 
 /* represents a string, where length and capacity are stored alongside the string data. */
 typedef struct
@@ -25,5 +26,7 @@ bool str_starts_with (const str_t *str, const char *find); /* check if a str_t s
 bool str_starts_with_len (const str_t *str, const char *find, size_t len); /* check if a str_t string starts with a cstring of given length. */
 bool str_ends_with (const str_t *str, const char *find); /* check if a str_t string ends with a cstring. */
 bool str_ends_with_len (const str_t *str, const char *find, size_t len); /* check if a str_t string ends with a cstring of given length. */
+char *str_find (const str_t *str, const char *find); /* find a substring in a str_t string as a pointer. */
+ssize_t str_pos (const str_t *str, const char *find); /* find the index of a substring in a str_t string. */
 
 #endif // CUTILS_STR_H_
diff --git a/lib/str.c b/lib/str.c
index c8ff4ad..7326782 100644
--- a/lib/str.c
+++ b/lib/str.c
@@ -208,3 +208,38 @@ str_ends_with_len (const str_t *str, const char *find, size_t len)
 {
     return strcmp (str->str + str->len - len, find) == 0;
 }
+
+/**
+ * find a substring in a str_t string. a pointer to the beginning of the
+ * substring is returned.
+ *
+ * @param   str: the str_t string to search in
+ * @param   find: the cstring to search for
+ *
+ * @return  beginning of found substring as pointer, or NULL if not found
+ */
+inline char *
+str_find (const str_t *str, const char *find)
+{
+    return strstr (str->str, find);
+}
+
+/**
+ * find a substring in a str_t string. the starting index of the substring is
+ * returned.
+ *
+ * @param   str: the str_t string to search in
+ * @param   find: the cstring to search for
+ *
+ * @return  beginning of found substring as string index, or -1 if not found
+ */
+ssize_t
+str_pos (const str_t *str, const char *find)
+{
+    char *pos;
+
+    pos = str_find (str, find);
+    if (pos)
+        return pos - str->str;
+    return -1;
+}
diff --git a/test/main.c b/test/main.c
index 7e21aec..c1b807f 100644
--- a/test/main.c
+++ b/test/main.c
@@ -95,6 +95,11 @@ test_str (void)
     test_add (&group, test_assert (!str_starts_with (&str, "foo")), "str_starts_with false");
     test_add (&group, test_assert (str_ends_with (&str, "elit.")), "str_ends_with true");
     test_add (&group, test_assert (!str_ends_with (&str, "bar")), "str_ends_with false");
+
+    test_add (&group, test_assert (str_find (&str, "ipsum") == str.str + 6), "str_find success");
+    test_add (&group, test_assert (str_find (&str, "foo") == NULL), "str_find failure");
+    test_add (&group, test_assert (str_pos (&str, "ipsum") == 6), "str_pos success");
+    test_add (&group, test_assert (str_pos (&str, "foo") == -1), "str_pos failure");
     str_free (&str);
 
     return test_group_get_results (&group);