PHPlanguage files Teppo Risnen Principal Lecturer Oulu University

PHP-language, files Teppo Räisänen Principal Lecturer Oulu University of Applied Sciences School of Business

Why files? • • To store data Simple to use No database available When

Basic steps using files from application 1. 2. 3. 4. 5. Open file (Lock

Opening file • Usually it is wise that applications don’t create file (necessary files

fopen() $filehandle=fopen(”. . /somefile. csv”, ”w”); … • Opening modes r=read w=write a=append •

fwrite() $filehandle=fopen(”. . /somefile. csv”, ”w”); flock($filehandle, LOCK_EX); fwrite($filehandle, ”Content to be added to

Reading a file <? php $filehandle=fopen(”…/. . /data. csv”, ”r”); while (!feof($filehandle)) //Check if

fclose() $filehandle=fopen(”. . /somefile. csv”, ”r”); fclose($filehandle); • You’ll have to ALWAYS remember to

Using files in Applications • Data is stored to file using e. g. delimeter

Exercise • Implement simple guestbook which stores messages to csv-file

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PHP-language, files Teppo Räisänen Principal Lecturer Oulu University of Applied Sciences School 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. 2. 3. 4. 5. Open file (Lock file while reading) Read from/write to file (Release locking) 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 modes r=read w=write a=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 file print ”$row ”; //Print row without any formatting } fclose($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