Post on 16-Dec-2015
PHP-language, files
Teppo RäisänenPrincipal Lecturer
Oulu University of Applied SciencesSchool of Business and Information Management
teppo.raisanen@oamk.fi, 050 382 6587
Why files?
• To store data• Simple to use• No database available• When storing complex data - use database
Basic steps using files from application
1. Open file2. (Lock file while reading)3. Read from/write to file4. (Release locking)5. Close file
Opening file
• Usually it is wise that applications don’t create file (necessary files are created manually during application setup)
• Files must be NEVER stored under public_html
fopen()
$filehandle=fopen(”../somefile.csv”,”w”);…
• Opening modesr=readw=writea=append• Check for more modes on PHP-manual
fwrite()
$filehandle=fopen(”../somefile.csv”,”w”);flock($filehandle,LOCK_EX);fwrite($filehandle,”Content to be added to file.”);flock($filehandle,LOCK_UN);fclose($filehandle);
Reading a file<?php$filehandle=fopen(”…/../data.csv”,”r”);while (!feof($filehandle)) //Check if we have reached end of file{
$row=fgets($filehandle); //Read current row from fileprint ”$row<br>”; //Print row without any formatting
}fclose($filehandle);?>
Note that $row=fread($filehandle, 1024) works also
fclose()
$filehandle=fopen(”../somefile.csv”,”r”);fclose($filehandle);
• You’ll have to ALWAYS remember to close to used file!
Using files in Applications
• Data is stored to file using e.g. delimeter character
• For example csv-file (Comma separated value)
Exercise
• Implement simple guestbook which stores messages to csv-file