/in/foo.c: In function 'fun':
/in/foo.c:5:18: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
     char* temp = str1;
                  ^~~~
/in/foo.c:6:9: warning: unused variable 'l1' [-Wunused-variable]
     int l1 = strlen(str1);
         ^~
/in/foo.c: In function 'main':
/in/foo.c:19:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(str1,1500,stdin);
     ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:19:5: error: too many arguments to function 'gets'
     gets(str1,1500,stdin);
     ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:20:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(str2, 300, stdin);
     ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:20:5: error: too many arguments to function 'gets'
     gets(str2, 300, stdin);
     ^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~