The following limitations must be observed when you code control processing in C language:

• None of the following functions can be used; using them might result in serious adverse effects on the HiRDB operation:
  
  • Process manipulation functions, such as fork(), exit(), abort(), and exec()
  • sleep(),select(),wait()
  • Stack manipulation functions (such as setjmp() and longjmp())
  • Shared memory manipulation functions
  • Semaphore manipulation functions
  • Socket manipulation functions
  • System resource manipulation functions (such as setrlimit)
  • mmap(),munmap()
  • gethostent(),sethostent(),endhostent(),gethostbyname(),gethostbyaddr(),herror()
  • tempnam(),tmpnam()
  • pstat()
  • system()
• Do not create threads.
• Do not use GUI.
• SQL statements cannot be specified.
• Do not manipulate files.
• Do not use special files (such as PIPE).
• Do not use the standard input, standard output, or standard error output.
• Do not use recursive function calls.
• None of the following names is permitted as global variable and function names:
  
  • Names beginning with the upper-case letters SQL, Y, or Z
  • Names beginning with the lower-case letters p_, pd, yy, or z
  • Names beginning with the lower-case letter _p
  • Names beginning with the lower-case letters da, dbr, or dp
• Do not set or change environment variables.
• Do not perform signal manipulation.
• Do not change the system date or time.
• If you allocate memory, make sure that the memory is released when the routine terminates.
• The stack size cannot exceed 4,096 bytes.