Adds strclr() and strlclr()

string.asm

@@ -4,6 +4,8 @@ section	.text
 	global	strlcpy
 	global	strcat
 	global	strcmp
+	global	strclr
+	global	strlclr
 
 ;----- strlen(char* str) -----;
 ; return value: amount of characters before EOS was found
@@ -123,3 +125,35 @@ strcmp:
 	.quit:
 	leave
 	ret
+;----- strclr(char* str) -----;
+; Replaces all characters of a string with \0 untill EOS is found
+; returns amount of changed characters
+strclr:
+	push	rbp
+	mov	rbp, rsp
+
+	call	strlen
+	mov	rcx, rax
+	mov	rdx, rax
+	xor	rax, rax
+	cld
+    rep	stosb
+	mov	rax, rdx
+
+	leave
+	ret
+;----- strlclr(char* str, int size) -----;
+; Replaces characters of a string with \0, using arg size
+; <!> DANGEROUS FUNCTION, it might exceed string boundaries if used incorrectly. Use strclr() instead!
+; Function has no return value, rax is unmodified
+strlclr:
+	push	rbp
+	mov	rbp, rsp
+
+	mov	rcx, rsi
+	xor	rax, rax
+	cld
+    rep	stosb
+
+	leave
+	ret