The first
step to
take is to avoid many problems by using good programming and debugging
techniques. Your programs should check for a returned error after
each system call and print any that occur. For example, the following
program lines print an error message for read:
cc=read(sock,buffer,1000);
if (cc<0) {
perror ("reading message")
exit(1)
} |
Refer to the perror(3C) man
page for more information
. Also refer to the appropriate man page for information about errors
returned by the BSD Sockets system calls such as read.
You can also compile your program with the debugging option
(-g) and use one of the debuggers (e.g. cdb
or xdb) to help debug the programs.
It is possible that you could assign a reserved port address
and cause a service to fail. For example, if the nftdaemon
is not running, and you assign its port, when you try to start the
nftdaemon, it fails. See the
/etc/services
file for the list of reserved ports.
