From 17c6b30949ce7d4a293862ec8f9b873e17fe0cd8 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Thu, 17 Oct 2019 20:38:19 +0200
Subject: Optimized string functions

---
 src/kernel/lib/lib.h    |  6 ++----
 src/kernel/lib/string.c | 35 ++++++++++++++---------------------
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/src/kernel/lib/lib.h b/src/kernel/lib/lib.h
index 03b4a3e..6963498 100644
--- a/src/kernel/lib/lib.h
+++ b/src/kernel/lib/lib.h
@@ -22,17 +22,15 @@ size_t strcmp(const char *s1, const char *s2);
  * Append the data of src to dest
  * @param dest The string destination pointer
  * @param src The string pointer that will get appended
- * @return The modified dest pointer
  */
-char *strcat(char *dest, const char *src);
+void strcat(char *dest, const char *src);
 
 /**
  * Copy the data of src to dest
  * @param dest The copying destination pointer (gets replaced)
  * @param src The string pointer that will get copied
- * @return The modified dest pointer
  */
-char *strcpy(char *dest, const char *src);
+void strcpy(char *dest, const char *src);
 
 /**
  * Copy n data from src to dest
diff --git a/src/kernel/lib/string.c b/src/kernel/lib/string.c
index 1e41d15..11e6021 100644
--- a/src/kernel/lib/string.c
+++ b/src/kernel/lib/string.c
@@ -8,29 +8,22 @@ size_t strlen(const char *str) {
 }
 
 size_t strcmp(const char *s1, const char *s2) {
-    while (*s1 && (*s1 == *s2)) {
-        s1++;
-        s2++;
-    }
-    return *(const unsigned char *) s1 - *(const unsigned char *) s2;
+    size_t s_a = strlen(s1);
+    for (size_t i = 0; i < s_a; i++) if (s1[i] != s2[i]) return 1;
+    return 0;
 }
 
-char *strcat(char *dest, const char *src) {
-    unsigned int i = 0;
-    unsigned int j = 0;
-    for (i = 0; dest[i] != 0; i++) {}
-    for (j = 0; src[j] != 0; j++) {
-        dest[i + j] = src[j];
-    }
-    dest[i + j] = 0;
-    return dest;
+void strcat(char *dest, const char *src) {
+    size_t s_dest = strlen(dest);
+    size_t s_orig = strlen(src);
+
+    for (size_t i = 0; i < s_orig; i++) dest[s_dest + i] = src[i];
+    dest[s_dest + s_orig] = 0;
 }
 
-char *strcpy(char *dest, const char *src) {
-    unsigned int i = 0;
-    for (i = 0; src[i] != 0; i++) {
-        dest[i] = src[i];
-    }
-    dest[i] = 0;
-    return dest;
+void strcpy(char *dest, const char *src) {
+    size_t s_orig = strlen(src);
+
+    for (size_t i = 0; i < s_orig; i++) dest[i] = src[i];
+    dest[s_orig] = 0;
 }
-- 
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