Null_String

 VSI Pascal provides routines  for  manipulating  null-terminated
 strings.   These  routines use the predeclared type C_STR_T as a
 pointer to a null-terminated  character  string.   The  compiler
 assumes  that  buffers are large enough to hold their values and
 null-terminated  strings  are  actually  terminated  by  a  null
 character.

Additional information available:

C_STR           MALLOC_C_STR    PAS_STR         PAS_STRCPY