diff --git a/src/replaceStr/main.cpp b/src/replaceStr/main.cpp
deleted file mode 100644
index 645d2be..0000000
--- a/src/replaceStr/main.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-#include <tools.hpp>
-#include <string_view>
-
-void print_help(){
-    zt::print("if you want help please add \"-h\"\n");
-}
-
-int main(const int argc,const char *argv[]){
-    if(argc==1){
-        print_help();
-        exit(-1);
-    }
-
-    std::string argv1(argv[1]);
-    if(argc==2){
-        if(argv1=="-h"){
-            zt::print("help:\n","\tThis is a simple string replacer to replace characters of the same length.\n","\t<string> <character to be replaced> <character to replace>\n","\t\t-By Zengtudor\n");
-        }else{
-            print_help();
-        }
-    }else if(argc==4){
-        std::string_view be_replaced(argv[2]),to_replace(argv[3]);
-        if(be_replaced.size()!=to_replace.size()){
-            zt::eprint("The length of last two characters are not same!\n");
-            exit(-1);
-        }
-        for(auto i: zt::Range((size_t)0,argv1.size())){
-            if(argv1[i]==be_replaced[0]){
-                for(auto j: zt::Range((size_t)0,be_replaced.size())){
-                    if(argv1[i+j]!=be_replaced[j]){
-                        goto out_of_match;
-                    }
-                }
-                for(auto j:zt::Range((size_t)0,be_replaced.size())){
-                    argv1[i+j]=to_replace[j];
-                }
-            }
-            out_of_match:;
-        }   
-    }else{
-        print_help();
-    }
-
-    zt::print(argv1,"\n");
-}
\ No newline at end of file
diff --git a/src/repstr/main.cpp b/src/repstr/main.cpp
new file mode 100644
index 0000000..129ca8d
--- /dev/null
+++ b/src/repstr/main.cpp
@@ -0,0 +1,50 @@
+#include <stdexcept>
+#include <tools.hpp>
+#include <string_view>
+
+void print_help_exit(){
+    throw std::runtime_error("if you want help please add \"-h\"\n");
+}
+
+int main(const int argc,const char *argv[]){
+    try{
+        if(argc==1){
+            print_help_exit();
+        }
+
+        std::string argv1(argv[1]);
+        if(argc==2){
+            if(argv1=="-h"){
+                zt::print("help:\n","\tThis is a simple string replacer to replace characters of the same length.\n","\t<string> <character to be replaced> <character to replace>\n","\t\t-By Zengtudor\n");
+                return 0;
+            }else{
+                print_help_exit();
+            }
+        }else if(argc==4){
+            std::string_view be_replaced(argv[2]),to_replace(argv[3]);
+            if(be_replaced.size()!=to_replace.size()){
+                throw std::runtime_error("The length of last two characters are not same!\n");
+            }
+            for(auto i: zt::Range((size_t)0,argv1.size())){
+                if(argv1[i]==be_replaced[0]){
+                    for(auto j: zt::Range((size_t)0,be_replaced.size())){
+                        if(argv1[i+j]!=be_replaced[j]){
+                            goto out_of_match;
+                        }
+                    }
+                    for(auto j:zt::Range((size_t)0,be_replaced.size())){
+                        argv1[i+j]=to_replace[j];
+                    }
+                }
+                out_of_match:;
+            }   
+        }else{
+            print_help_exit();
+        }
+
+        zt::print(argv1,"\n");
+
+    }catch(std::runtime_error &e){
+        zt::eprint("caught an error because:\n","\te.what(): ",e.what(),"\n");
+    }
+}
\ No newline at end of file
diff --git a/xmake.lua b/xmake.lua
index d295fb9..bcc6f3e 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -6,6 +6,6 @@ set_warnings("all")
 
 add_includedirs("src/tools")
 
-target("replaceStr")
+target("repstr")
     set_kind("binary")
-    add_files("./src/replaceStr/*.cpp")
\ No newline at end of file
+    add_files("./src/repstr/*.cpp")
\ No newline at end of file