add an argument for filenames

.gitignore

@@ -1,6 +1,8 @@
 *.o
-lex.yy.c
+lex.yy.*
 as.tab.*
-output.asm
-output_bin.txt
+*.asm
+!input.asm
+*.txt
 cross_assembleur
+

as.y

@@ -62,13 +62,31 @@ Instruction : tCPY tNB tNB     {increment_time();
 
 %%
 
-int main(void) {
-	file = fopen("output.asm", "w");
-	file2 = fopen("output_bin.txt", "w");
+#include <string.h>
+
+int main(int argc, char *argv[]) {
+  char *output_filename = "output_cross";
+
+  if (argc >= 2) {
+      output_filename = argv[1];
+  }
+
+  char *asm_filename = malloc(strlen(output_filename) + 5);
+  char *bin_filename = malloc(strlen(output_filename) + 9);
+  strcpy(asm_filename, output_filename);
+  strcpy(bin_filename, output_filename);
+  strcat(asm_filename, ".asm");
+  strcat(bin_filename, "_bin.txt");
+
+  file = fopen(asm_filename, "w");
+  file2 = fopen(bin_filename, "w");
   init();
   yyparse();
   flush_and_init();
   write_asm(file);
   write_code_machine(file2);
+
+  free(asm_filename);
+  free(bin_filename);
   return 0;
 }