Files

• Files can be very useful in some applications

Files

• Working with files involves several functions, for example:
  • fopen($fileName, $mode) - returns a resource to the file or false, if it was unable to open file
  • fgets($resource) - returns a string up to a CRLF or EOF, if it runs out of data to read false is returned
  • fwrite($resource, $content) - returns number of bytes written or false
  • fclose($resource) - returns true if the file is successfully close, false if not
• Should always close the file resource when you are finished

Modes

• Modes
  • r - Read
  • w - Write (erase file if exists, create if not)
  • a - Append (create if does not exists, appends to end)
• Other modes exist but are not frequently used

Example File

• Name this file callList.csv

Dictum Eu Company,1-194-286-3041
Proin Industries,1-319-137-9279
Enim Sit Industries,1-562-872-9219
Phasellus In Corp,1-128-930-9807
Dolor Quam Elementum PC,1-928-801-9652
Nibh Lacinia Orci PC,1-332-594-5321
Donec Porttitor Tellus Company,1-873-991-8646
Ut Dolor Consulting,1-514-308-9570
Suspendisse Ac Metus PC,1-466-488-2655
Lorem Incorporated,1-778-863-7253
Curabitur Consequat Incorporated,1-496-807-1201
Non Company,1-383-777-6247
Enim Inc,1-441-333-2507
Quisque Libero Industries,1-821-364-5581
At Pretium Aliquet Incorporated,1-651-831-1982
Mi Consulting,1-358-903-2637
Lacus Varius LLP,1-493-938-0338
Nibh Dolor Foundation,1-706-129-8454
Risus Associates,1-657-994-6688
Viverra LLC,1-857-231-3877
Nunc Corp,1-652-403-0424
Praesent Luctus Curabitur Foundation,1-363-243-2228
Risus PC,1-110-328-3877
Eleifend Nunc Risus Associates,1-873-927-9209
Vel Convallis LLP,1-430-846-6335

Opening

• To open the file for reading
  • fopen() the file by providing the location and mode
  • Check if it is a resource
    • It is possible that the file does not exist, can not be accessed, etc…
      
  • Don’t forget to later close

$callList = fopen("callList.csv", "r");

if(!is_resource($callList))
{
    echo "Could not open file";
    exit();
}

//Do stuff with your file

fclose($callList);

Using

• There are many ways to work with the file
  • Could use fgetscsv() to parse csv but we would limit our learning today :)
  • We will use fgets()

//Open the file

while($line = fgets($callList))
{
    echo $line;
}

//Close the file

• What will $line contain during each iteration?
• When will this while loop end?

Parsing

• On first iteration:

//How can we turn this:
"Dictum Eu Company,1-194-286-3041"

//Into this:
array("Dictum Eu Company", "1-194-286-3041");

Explode

• Can use PHP functions to parse the line into an array for us¹
  • explode($delimiter, $source) - returns an array of strings by splitting it up using the delimiter
  • implode($delimiter, $source) - returns a string by combining all the elements of the array inserting the delimiter between each

$companies[]=explode(",", $line);

$line = implode(",",array("Dictum Eu Company", "1-194-286-3041"));

• Once all iterations have completed on callList.csv what will be in $companies[0]?

In Array

• in_array($needle, $haystack) - Searches the haystack (array) for the needle (element) and returns true if found, false if not

<?php

$colors = array("red", "green", "blue");

• How would you check to see if indigo is in the variable $colors using in_array()?

In Array

in_array("indigo",$colors);

Array Search

• array_search($needle, $haystack) - Searches the haystack (array) for the needle (element) and returns the key (or index) if found, false if not

Outputting

• Lets build the overview and details screen