From 6cdf20d9f230de54114c6ac1f2a55d99859762d7 Mon Sep 17 00:00:00 2001
From: Thomas Debesse <dev@illwieckz.net>
Date: Mon, 8 Jul 2024 01:34:40 +0200
Subject: [PATCH] examples: factorize strcpy

---
 example1/example1.cpp | 19 ++++---------------
 example2/example2.cpp | 36 +++++++++++++++++++++++++-----------
 example3/example3.cpp | 13 +++----------
 3 files changed, 32 insertions(+), 36 deletions(-)

diff --git a/example1/example1.cpp b/example1/example1.cpp
index 465ca3ac..72b65c0c 100644
--- a/example1/example1.cpp
+++ b/example1/example1.cpp
@@ -20,6 +20,7 @@
 #include "dds_defs.h"
 
 #include "crn_core.h"
+#include "crn_strutils.h"
 #include "crn_file_utils.h"
 
 // stb_image, for loading/saving image files.
@@ -313,11 +314,7 @@ int main(int argc, char* argv[]) {
       if (++i >= argc)
         return error("Expected output filename!");
 
-#if defined(_WIN32)
-      strcpy_s(out_filename, sizeof(out_filename), argv[i]);
-#else
-      strncpy(out_filename, argv[i], sizeof(out_filename));
-#endif
+      strcpy_safe(out_filename, sizeof(out_filename), argv[i]);
     } else if (!crnlib_stricmp(argv[i], "-nonsrgb"))
       srgb_colorspace = false;
     else if (!crnlib_stricmp(argv[i], "-nomips"))
@@ -482,11 +479,7 @@ int main(int argc, char* argv[]) {
     char dst_filename[FILENAME_MAX];
     crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s%s", drive.get_ptr(), dir.get_ptr(), fname.get_ptr(), output_crn ? ".crn" : ".dds");
     if (out_filename[0])
-#if defined(_WIN32)
-      strcpy_s(dst_filename, sizeof(dst_filename), out_filename);
-#else
-      strncpy(dst_filename, out_filename, sizeof(dst_filename));
-#endif
+      strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);
 
     printf("Writing %s file: %s\n", output_crn ? "CRN" : "DDS", dst_filename);
     FILE* pFile = NULL;
@@ -516,11 +509,7 @@ int main(int argc, char* argv[]) {
     char dst_filename[FILENAME_MAX];
     crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s.dds", drive.get_ptr(), dir.get_ptr(), fname.get_ptr());
     if (out_filename[0])
-#if defined(_WIN32)
-      strcpy_s(dst_filename, sizeof(dst_filename), out_filename);
-#else
-      strncpy(dst_filename, out_filename, sizeof(dst_filename));
-#endif
+      strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);
 
     printf("Writing file: %s\n", dst_filename);
     FILE* pFile = NULL;
diff --git a/example2/example2.cpp b/example2/example2.cpp
index 3c6d845d..c19bb7c5 100644
--- a/example2/example2.cpp
+++ b/example2/example2.cpp
@@ -28,11 +28,29 @@
 
 using namespace crnlib;
 
-#if defined(_WIN32)
-#define example2_strncpy(out, in, size) strcpy_s(out, size, in)
-#else
-#define example2_strncpy(out, in, size) strncpy(out, in, size)
-#endif
+// Copied from crn_strutils.cpp without asserts.
+char* example2_strcpy_safe(char* pDst, uint dst_len, const char* pSrc) {
+  if (!dst_len)
+    return pDst;
+
+  char* q = pDst;
+  char c;
+
+  do {
+    if (dst_len == 1) {
+      *q++ = '\0';
+      break;
+    }
+
+    c = *pSrc++;
+    *q++ = c;
+
+    dst_len--;
+
+  } while (c);
+
+  return pDst;
+}
 
 static int print_usage() {
   printf("Description: Transcodes .CRN to .DDS files using crn_decomp.h.\n");
@@ -96,11 +114,7 @@ int main(int argc, char* argv[]) {
       if (++i >= argc)
         return error("Expected output filename!");
 
-#if defined(_WIN32)
-      strcpy_s(out_filename, sizeof(out_filename), argv[i]);
-#else
-      strncpy(out_filename, argv[i], sizeof(out_filename));
-#endif
+      example2_strcpy_safe(out_filename, sizeof(out_filename), argv[i]);
     } else
       return error("Invalid option: %s\n", argv[i]);
   }
@@ -143,7 +157,7 @@ int main(int argc, char* argv[]) {
   // Now create the DDS file.
   char dst_filename[FILENAME_MAX];
   if (out_filename[0]) {
-    strcpy(dst_filename, out_filename);
+    example2_strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);
   } else {
     unsigned int stripped_length = UINT32_MAX;
     const char* ext_begin = strrchr(pSrc_filename, '.');
diff --git a/example3/example3.cpp b/example3/example3.cpp
index 685af177..aa11da45 100644
--- a/example3/example3.cpp
+++ b/example3/example3.cpp
@@ -19,6 +19,7 @@
 #include "dds_defs.h"
 
 #include "crn_core.h"
+#include "crn_strutils.h"
 #include "crn_file_utils.h"
 
 // stb_image, for loading/saving image files.
@@ -94,11 +95,7 @@ int main(int argc, char* argv[]) {
       if (++i >= argc)
         return error("Expected output filename!");
 
-#if defined(_WIN32)
-      strcpy_s(out_filename, sizeof(out_filename), argv[i]);
-#else
-      strncpy(out_filename, argv[i], sizeof(out_filename));
-#endif
+      strcpy_safe(out_filename, sizeof(out_filename), argv[i]);
     } else if (!crnlib_stricmp(argv[i], "-nonsrgb"))
       srgb_colorspace = false;
     else if (!crnlib_stricmp(argv[i], "-pixelformat")) {
@@ -233,11 +230,7 @@ int main(int argc, char* argv[]) {
   char dst_filename[FILENAME_MAX];
   crnlib_snprintf(dst_filename, sizeof(dst_filename), "%s%s%s.dds", drive.get_ptr(), dir.get_ptr(), fname.get_ptr());
   if (out_filename[0])
-#if defined(_WIN32)
-      strcpy_s(dst_filename, sizeof(dst_filename), out_filename);
-#else
-      strncpy(dst_filename, out_filename, sizeof(dst_filename));
-#endif
+    strcpy_safe(dst_filename, sizeof(dst_filename), out_filename);
 
   printf("Writing DDS file: %s\n", dst_filename);