From 1778dbde853e9c2eab8122b19bf6e3671e2cca99 Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Thu, 14 Jun 2018 10:48:44 +0200
Subject: [PATCH] fmt: Add fmt_strnlen function
---
sys/fmt/fmt.c | 9 +++++++++
sys/include/fmt.h | 11 +++++++++++
2 files changed, 20 insertions(+)
diff --git a/sys/fmt/fmt.c b/sys/fmt/fmt.c
index e75c7487a3..5ea21e8b8e 100644
--- a/sys/fmt/fmt.c
+++ b/sys/fmt/fmt.c
@@ -83,6 +83,15 @@ size_t fmt_strlen(const char *str)
return (tmp - str);
}
+size_t fmt_strnlen(const char *str, size_t maxlen)
+{
+ const char *tmp = str;
+ while(*tmp && maxlen--) {
+ tmp++;
+ }
+ return (tmp - str);
+}
+
size_t fmt_str(char *out, const char *str)
{
int len = 0;
diff --git a/sys/include/fmt.h b/sys/include/fmt.h
index d88608b2c9..229f939611 100644
--- a/sys/include/fmt.h
+++ b/sys/include/fmt.h
@@ -294,6 +294,17 @@ size_t fmt_float(char *out, float f, unsigned precision);
*/
size_t fmt_strlen(const char *str);
+/**
+ * @brief Count at most @p maxlen characters until '\0' (exclusive) in @p str
+ *
+ * @param[in] str Pointer to string
+ * @param[in] maxlen Maximum number of chars to count
+ *
+ * @return nr of characters in string @p str points to, or @p maxlen if no
+ * null terminator is found within @p maxlen chars
+ */
+size_t fmt_strnlen(const char *str, size_t maxlen);
+
/**
* @brief Copy null-terminated string (excluding terminating \0)
*
--
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