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       asp - find an host IP address by its name


       asp  [-uv] [-f | [-d dir] [-e ext]] [-a addresses] [-r repetitions] [-s
       send_delay] [-w wait_time] [-p port] hostname
       asp -V


       Asp finds the IP address of an Internet connected  host.  In  order  to
       find  it,  the  peer  hostname  (not  the  FQDN),  and the range of its
       possible IP addresses need to be specified. Those IP addresses could be
       simple  IP addresses as or "metaip" addresses as
       or 127.0.0.*: the former is a simple way to avoid  to  type  a  lot  of
       consecutive addresses, the latter is short for

       In  order  to  simplify  the  management  of  the  associations between
       hostnames and addresses, asp searches in a specified directory  a  text
       file  containing  the possible IP addresses of the looked for host. The
       name of the text file has to be formed by the hostname followed  by  an
       optional extension of your choice.

       For  example to find the author’s dynamic IP address, obviously if I am
       on line, you can provide my metaip address on standard input  with  the

              echo "
    " | asp -f atomic

       or you can put my metaip address in a file called atomic in your ~/.asp
       directory, like this:

              echo "
    " > ~/.asp/atomic

       and then you can simply do:

              asp atomic


       -u     Update the file /etc/hosts with the IP address  of  hostname  or
              delete  the  possible  old  entry  if  the address is not found.
              Obviously the file have to by writable by the user.

       -v     Include  more  verbiage  to  make  output  readable  by  humans.
              Default  consists  only  of  dotted  quad  IP  address, which is
              intended for output substitution in scripts.

       -f     Force the reading of addresses from standard input instead  that
              from the hostname’s file.

       -d dir
              Set  the  directory  containing  the  addresses file referred by
              hostname to dir.  Default is ~/.asp.

       -e ext
              Set addresses files extension to ext.  Default is no  extension.

       -a addresses
              Set  the  number  of  queries  to  send  before  make a pause of
              send_delay seconds. Default is 12 queries.

       -r repetitions
              Set the number of times to try the same address.  Default  is  3

       -s send_delay
              Delay  the  sending  of  the  next group of addresses send_delay
              seconds. Default is 2 seconds.

       -w wait_time
              Wait the peer reply for wait_time seconds. Default is 5 seconds.

       -p port
              Specify  an alternative port number. For default the port number
              is obtained searching the asp entry in /etc/services.

       -V     Show version information.


       ASPCMD This variable could be used to store your preferred settings. An
              option  set  in this environment variable could be overridden or
              toggled from command line.


       UDP is an unreliable protocol, therefore there is a chance you will not
       find  the  host even if it is on line. Anyway, if you are sure that the
       peer is on line and asp aware, you could adjust the various  parameters
       until  you  get a reply. At last you will find the correct settings for
       your particular needs. This until the RDM communication style  will  be
       implemented under Linux.

       Obviously  the  hostname  has  to  be  unique  among  the  possible  IP
       addresses: asp will hook to the first correct reply.


       Stenio Brunetta <>

       Comments and suggestions are welcome.


       Steven N. Hirsch <> for v1.3 bug fix and for the verbose
       Colin Phipps <> for the tmpnam security issue.