Index

1. Stage 4: creating an expect script to telnet

• run the telnet command to login to a remote machine
• note the output carefully:

• Trying 192.168.0.1...
  Connected to merlin.
  Escape character is ’^]’.
  Debian GNU/Linux 2.2 merlin
  merlin login: foobar
  Password:
  Last login: Mon Mar  4 11:50:37 2002

2. Expect script considerations

• consider what happens if the wrong username or password is issued:

• telnet merlin
  Trying 192.168.0.1...
  Connected to merlin.
  Escape character is ’^]’.
  Debian GNU/Linux 2.2 merlin
  merlin login: foobar
  Password:
  Login incorrect
  merlin login:
  Login timed out after 60 seconds.
  Connection closed by foreign host.

• how should our expect script catch this case?
  

3. Tutorial/Lab/Assignment help

• write an expect script which takes 3 or 4 arguments
  • first argument is the machinename
  • second argument is the username
  • third argument is the password
  • optional fourth argument is -a if the telnet session is to be closed
    • in this case consider making your expect script exit with 0 if login was successful and exit with a 1 if it failed

4. Tutorial/Lab/Assignment help

• modify your autotel script to obey the -h option (as specified in the assignment)
• now modify your autotel script to call your expect script with the appropriate parameters
• now modify the autotel script to obey the -a option
  • in this case it should check the exit code from the expect script

5. autoftp revisited (part 1)

• #!/bin/sh
  
  scriptname=$0   # $0 is the name of the program
  verbose=no
  probeonly=no
  TMP=/tmp/auto.$$
  
  
  function usage () {
     cat <<EOF
  Usage: $scriptname [-p] [-v] [-h] filename
     -p   probes the ftp sites and check urls in
          filename
     -v   executes and prints out verbose messages
     -h   displays basic help
  EOF
     exit 0
  }

6. autoftp revisited (part 2)

• #
  #  findSiteDirFile - given a line $1 in the form
  #                    site/dir/file extract the
  #                    site dir and file components
  
  
  function findSiteDirFile () {
     j=1
     SITE=‘echo $1 | cut -d ’/’ -f 1‘
     rest=‘echo $1 | cut -d ’/’ -f 2-‘
     if [ "‘echo $rest | \
          cut -f 1 -d ’/’‘" = "$rest" ]
     then
        FILE=$rest
        DIR="/"
     else
        while [ "‘echo $rest | \
                cut -f $j -d ’/’‘" != "" ]
        do
           j=‘expr $j + 1‘
        done
        j=‘expr $j - 1‘
        FILE=‘echo $rest | cut -f $j -d ’/’‘
        j=‘expr $j - 1‘
        DIR=‘echo $rest | cut -f -$j -d ’/’‘
     fi
  }

7. autoftp revisited (part 3)

• function scanURLs () {
     cut -d ’#’ -f1 $1 > $TMP
     n=‘wc -l $TMP | cut -b 0-7‘
     i=1
     while [ $i -le $n ]
     do
        line=‘head -$i $TMP | tail -1‘
        if [ "$line" != "" ]
        then
            findSiteDirFile $line
            echo "site is" $SITE "file is" $FILE \
                 "dir is" $DIR
            exp7.exp $SITE $DIR $FILE
        fi
        i=‘expr $i + 1‘
     done
  }

8. autoftp revisited (part 4)

• while getopts ":pvh" opt; do
     case $opt in
  
     v )  verbose=yes ;;
     p )  probeonly=yes ;;
     h )  usage ;;
     \?)  usage ;;
     esac
  done
  
  shift $(($OPTIND - 1))
  
  PATH=$PATH:.
  scanURLs $1
  
  /bin/rm -f $TMP

9. autoftp in action!

• fred@merlin:$ ./autoftp4.sh autoftprc
  site is guenevere file is m2f_4.2-1_i386.deb \
  dir is pub/deb/dists/unstable/contrib/binary-i386
  spawn ftp guenevere
  Connected to guenevere.
  220 guenevere FTP server (Version wu-2.6.0(1).
  Name (guenevere:fred): anonymous
  331 Guest login ok, send your complete e-mail \
  address as password.
  Password:
  230-Welcome, archive user anonymous@merlin !
  230 Guest login ok, access restrictions apply.
  Remote system type is UNIX.
  Using binary mode to transfer files.
  ftp> binary
  200 Type set to I.
  ftp> cd pub/deb/dists/unstable/contrib/binary-i386
  250 CWD command successful.
  ftp> get m2f_4.2-1_i386.deb
  local: m2f_4.2-1_i386.deb
  200 PORT command successful.
  150 Opening BINARY mode data connection for
  m2f_4.2-1_i386.deb (1663122 bytes).
  226 Transfer complete.
  1663122 bytes received in 0.62 secs (2622.1 kB/s)
  ftp> quit
  221-You have transferred 1663122 bytes in 1 files.
  221-Total traffic was 1664135 bytes
  in 1 transfers.
  221-Thank you for using the FTP service.
  221 Goodbye.

10. autoftp

• will now download files from a remote site
  • currently it is always verbose
  • alter the script to silence the output unless the -v option is present
• think how you would implement the probe only -p switch
  • we leave this as an exercise for the reader

Index

This document was produced using groff-1.19.