#include<stdio.h>
char *stcat(char *s,char *t)
{
if((s==NULL)||(t==NULL))
perror("error");
char *pt=s;
while(*s!='\0') s++;
while(*t!='\0') *s++=*t++;
*s='\0';
return pt;
}
int main()
{
char s[100]="markyuan";
char t[]="aaaaaaaaaaa";
printf("strlen(*s)=%s\n",s);
char *cat=stcat(s,t);
printf("strlen(*s)=%s\n",s);
printf("%s\n",'\0');
}