CS 330 Class 7

1
CS 330 Class 7

• Programming plan for Oct 15, 2007
• start PHP
• logistics
• Reading (Williams and Lane)
• heavy emphasis on string manipulation. Why?
• picking apart user input, file names, urls
• use text as you need it
• Supplement Programming PHP in TA office
• Reference www.php.net

2
Begin PHP

• Syntax similar to C
• Embedded between lt?php ?gt or lt? ?gt
• .php file extension
• time.php
• ltbodygt
• lt?php echo date("his a", time()) ?gt
• lt!-- time() is the current time, date formats
  it --gt
• lt/bodygt
• lt/htmlgt
• echo prints to the page

3
More on time()

• What would this produce ?
• lt?php echo time() ?gt //(time2.php)
• The seconds since 1/1/70 GMT
• Used for time stamping
• Many functions for converting between this and
  dates
• Problem stored as 32 bit integer and runs out in
  2038
• microtime() for generating subseconds

4
Passing Data to the Server

• Passed with the HTTP header
• environment variables describing host and
  client environments
• form variables describing data sent with a form
• Environment variables stored in the associative
  array
• _ENV (preferred) or
• HTTP_ENV_VARS
• env1.php
• ltbodygt
• Server name lt?php echo _ENV'SERVER_NAME'?
  gtltbr /gt
• Running on port lt?php echo _ENV'SERVER_PORT'?
  gt ltbr /gt
• Server software lt?php echo _ENV'SERVER_SOFTWARE
  '?gt ltbr /gt
• Server protocol lt?php echo _ENV'SERVER_PROTOCOL
  '?gt ltbr /gt
• lt/bodygt
• env2.php
• lt?php phpinfo() ?gt //phpinfo is a built-in
  function
• an array whose subscripts are text

5

• Restricting Page Access
• restrict.php
• lt?php
• restrict access depending on user domain
• remoteaddr _ENV'REMOTE_ADDR'
• if (ereg(remoteaddr, '10\.3/'))
• header('Location examples.htm')
• else
• echo "Access restricted to Wells campus",
  "\n\n"
• ?gt
• What do you think ereg is?

6
Server Variables

• server.php
• lthtmlgt
• ltheadgt
• lttitlegtServer Variableslt/titlegt
• lt/headgt
• ltbodygt
• lt?php
• foreach (_SERVER as key gtval)
• echo '_SERVER'. key ." valltbr /gt"
• ?gt
• lt/bodygt
• lt/htmlgt
• Syntax
• foreach goes through each element in _SERVER
• keygtval val is the value associated with
  subscript key
• 'contents' are literal, "contents" are interpreted

7
Echoing Form Information (Via Get)

• form1.php (triggered by form1.htm)
• lthtmlgtltheadgtlttitlegtSimple Form Processinglt/titlegtlt
  /headgt
• ltbodygt
• lth2gtSimple Form Processinglt/h2gt
• lthrgt
• The query string is 'lt?php echo
  _ENV'QUERY_STRING' ?gt'
• ltbr /gtltbr /gt
• Form variable 'Name' has value lt?php echo
  _GET'Name' ?gt
• ltbr /gtltbr /gt
• lt?php form split ("",_ENV'QUERY_STRING')
  ?gt
• The field lt?php echo form'0'?gt
• ltbr /gt
• The data lt?php echo form'1' ?gt
• lthrgt
• lt/bodygt
• lt/htmlgt

8

• Good News if you know the fields, you don't
  need "split"
• form2.php (from form2.htm)
• lthtmlgt
• ltheadgtlttitlegtForm2lt/titlegtlt/headgt
• ltbodygt
• lth2gtForm Processing 2lt/h2gt
• lthrgt
• The query string is 'lt?php echo
  _ENV'QUERY_STRING' ?gt'ltbr /gt
• Form variable 'Name' has value 'lt?php echo
  _GET'Name'?gt'ltbr /gt
• Form variable 'Field' has value 'lt?php echo
  _GET'Field'?gt'
• lthrgt
• lt/body
• lt/htmlgt

9

• form2p.php (from form2p.htm)
• lthtmlgt
• ltheadgtlttitlegtForm 2 Postlt/titlegtlt/headgt
• ltbodygt
• lth2gtForm Processing 2, Postlt/h2gt
• lthrgt
• Form variable 'Name' has value 'lt?php echo
  _POST'Name'?gt'ltbr /gt
• Form variable 'Field' has value 'lt?php echo
  _POST'Field'?gt'
• lthrgt
• lt/bodygt
• lt/htmlgt

10
Logistics

• On your machine download php from
  http//www.php.net/
• On max.wells.edu (24.39.181.217, 10.3.6.111)
• you each have a directory home/yourname
• my files are in /carol/php
• More Professor Zhu