C/stdio.h/getchar

    
//Header file:     #include <stdio.h>  
//Declaration:     int getchar(void); 
//Return:          returns EOF on error. 

  #include <stdio.h>
  int main(void)
  {
    char s[256], *p;
    p = s;
    printf("input char:");
    while((*p++ = getchar())!= "\n");
    *p = "\0"; /* add null terminator */
    printf(s);
    return 0;
  }
         
/*
input char:123
123
*/