Add strnchr() and crlf2nl()

Signed-off-by: Simon Rozman <simon@rozman.si>

include/stdex/sal.h

@@ -33,6 +33,9 @@
 #ifndef _In_z_count_
 #define _In_z_count_(p)
 #endif
+#ifndef _In_reads_or_z_
+#define _In_reads_or_z_(p)
+#endif
 
 #ifndef _Inout_
 #define _Inout_
@@ -48,6 +51,9 @@
 #ifndef _Out_opt_
 #define _Out_opt_
 #endif
+#ifndef _Out_writes_z_
+#define _Out_writes_z_(p)
+#endif
 
 #ifndef _Success_
 #define _Success_(p)

include/stdex/string.h

@@ -0,0 +1,71 @@
+/*
+    SPDX-License-Identifier: MIT
+    Copyright © 2016-2022 Amebis
+*/
+
+#pragma once
+
+#include "sal.h"
+
+namespace stdex
+{
+    ///
+    /// Calculate zero-terminated string length.
+    ///
+    /// \param[in] str  String
+    ///
+    /// \return Number of characters excluding zero terminator in the string.
+    ///
+    template <class T>
+    inline size_t strlen(_In_z_ const T* str)
+    {
+        size_t i;
+        for (i = 0; str[i]; i++);
+        return i;
+    }
+
+    ///
+    /// Finds a character in a string.
+    ///
+    /// \param[in] str    String
+    /// \param[in] chr    Character to search for
+    /// \param[in] count  Maximum number of characters in string str to search for
+    ///
+    /// \return Pointer to the first occurence of chr character or NULL if not found.
+    ///
+    template <class T>
+    inline const T* strnchr(
+        _In_reads_or_z_(count) const T* str,
+        _In_ T chr,
+        _In_ size_t count)
+    {
+        for (size_t i = 0; i < count && str[i]; i++)
+            if (str[i] == chr) return str + i;
+        return NULL;
+    }
+
+    ///
+    /// Convert CRLF to LF
+    /// Source and destination strings may point to the same buffer for inline conversion.
+    ///
+    /// \param[in] dst  Destination string - must be same or longer than src
+    /// \param[in] src  Source string
+    ///
+    /// \return Number of characters excluding zero terminator in the dst string after the operation.
+    ///
+    template <class T>
+    inline size_t crlf2nl(_Out_writes_z_(strlen(src)) T* dst, _In_z_ const T* src)
+    {
+        size_t i, j;
+        for (i = j = 0; src[j];) {
+            if (src[j] != (T)'\r' || src[j + 1] != (T)'\n')
+                dst[i++] = src[j++];
+            else {
+                dst[i++] = (T)'\n';
+                j += 2;
+            }
+        }
+        dst[i] = (T)0;
+        return i;
+    }
+}