php i basic chapter 4

Download Php i basic chapter 4

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  • 1. PHP Workshop 1File Handling with PHP

2. PHP Workshop 2Files and PHP File Handling Data Storage Though slower than a database Manipulating uploaded files From forms Creating Files for download 3. PHP Workshop 3Open/Close a File A file is opened with fopen() as a stream,and PHP returns a handle to the file thatcan be used to reference the open file inother functions. Each file is opened in a particular mode. A file is closed with fclose() or when yourscript ends. 4. PHP Workshop 4File Open Modesr Open for reading only. Start at beginning offile.r+ Open for reading and writing. Start atbeginning of file.w Open for writing only. Remove all previouscontent, if file doesnt exist, create it.a Open writing, but start at END of currentcontent.a+ Open for reading and writing, start at ENDand create file if necessary. 5. PHP Workshop 5File Open/Close Example 6. PHP Workshop 6Now what..? If you open a file to read, you can usemore in-built PHP functions to read data.. If you open the file to write, you can usemore in-built PHP functions to write.. 7. PHP Workshop 7Reading Data There are two main functions to read data: fgets($handle,$bytes) Reads up to $bytes of data, stops at newlineor end of file (EOF) fread($handle,$bytes) Reads up to $bytes of data, stops at EOF. 8. PHP Workshop 8Reading Data We need to be aware of the End Of File(EOF) point.. feof($handle) Whether the file has reached the EOF point.Returns true if have reached EOF. 9. PHP Workshop 9Data Reading Example$handle = fopen(people.txt, r);while (!feof($handle)) {echo fgets($handle, 1024);echo
;}fclose($handle); 10. PHP Workshop 10Data Reading Example$handle = fopen(people.txt, r);while (!feof($handle)) {echo fgets($handle, 1024);echo
;}fclose($handle);Open the file and assign the resource to $handle$handle = fopen(people.txt, r); 11. PHP Workshop 11Data Reading Example$handle = fopen(people.txt, r);while (!feof($handle)) {echo fgets($handle, 1024);echo
;}fclose($handle);While NOT at the end of the file, pointedto by $handle,get and echo the data line by linewhile (!feof($handle)) {echo fgets($handle, 1024);echo
;} 12. PHP Workshop 12Data Reading Example$handle = fopen(people.txt, r);while (!feof($handle)) {echo fgets($handle, 1024);echo
;}fclose($handle);Close the filefclose($handle); 13. PHP Workshop 13File Open shortcuts.. There are two shortcut functions that dontrequire a file to be opened: $lines = file($filename) Reads entire file into an array with each line aseparate entry in the array. $str = file_get_contents($filename) Reads entire file into a single string. 14. PHP Workshop 14Writing Data To write data to a file use: fwrite($handle,$data) Write $data to the file. 15. PHP Workshop 15Data Writing Example$handle = fopen(people.txt, a);fwrite($handle, nFred:Male);fclose($handle); 16. PHP Workshop 16Data Writing Example$handle = fopen(people.txt, a);fwrite($handle, nFred:Male);fclose($handle);$handle = fopen(people.txt, a);Open file to append data (mode a)fwrite($handle, nFred:Male);Write new data (with linebreak after previous data) 17. PHP Workshop 17Other File Operations Delete file unlink(filename); Rename (file or directory) rename(old name, new name); Copy file copy(source, destination); And many, many more! www.php.net/manual/en/ref.filesystem.php 18. PHP Workshop 18Dealing With Directories Open a directory $handle = opendir(dirname); $handle points to the directory Read contents of directory readdir($handle) Returns name of next file in directory Files are sorted as on filesystem Close a directory closedir($handle) Closes directory stream 19. PHP Workshop 19Directory Example$handle = opendir(./);while(false !== ($file=readdir($handle))){echo "$file
";}closedir($handle); 20. PHP Workshop 20Directory Example$handle = opendir(./);while(false !== ($file=readdir($handle))){echo "$file
";}closedir($handle);Open current directory$handle = opendir(./); 21. PHP Workshop 21Directory Example$handle = opendir(./);while(false !== ($file=readdir($handle))){echo "$file
";}closedir($handle);Whilst readdir() returns a name, loopthrough directory contents, echoingresultswhile(false !== ($file=readdir($handle))){echo "$file
";} 22. PHP Workshop 22Directory Example$handle = opendir(./);while(false !== ($file=readdir($handle))){echo "$file
";}closedir($handle);Close the directory streamclosedir($handle); 23. PHP Workshop 23Other Directory Operations Get current directory getcwd() Change Directory chdir(dirname); Create directory mkdir(dirname); Delete directory (MUST be empty) rmdir(dirname); And more! www.php.net/manual/en/ref.dir.php 24. PHP Workshop 24Review Can open and close files. Can read a file line by line or all at one go. Can write to files. Can open and cycle through the files in adirectory. 25. PHP Workshop 25Review all Create a File$my_file = file.txt;$handle = fopen($my_file, w) ordie(Cannot open file: .$my_file);//implicitly creates file 26. PHP Workshop 26Review all Open a File$my_file = file.txt;$handle = fopen($my_file, w) ordie(Cannot open file: .$my_file); //openfile for writing (w,r,a)... 27. PHP Workshop 27Review all Read a File$my_file = file.txt;$handle = fopen($my_file, r);$data = fread($handle,filesize($my_file)); 28. PHP Workshop 28Review all Write to a File$my_file = file.txt;$handle = fopen($my_file, w) ordie(Cannot open file: .$my_file);$data = This is the data;fwrite($handle, $data); 29. PHP Workshop 29Review all Append to a File$my_file = file.txt;$handle = fopen($my_file, a) or die(Cannotopen file: .$my_file);$data = New data line 1;fwrite($handle, $data);$new_data = "n".New data line 2;fwrite($handle, $new_data); 30. PHP Workshop 30Review all Close a File$my_file = file.txt;$handle = fopen($my_file, w) ordie(Cannot open file: .$my_file);//write some data herefclose($handle); 31. PHP Workshop 31Review all Delete a File$my_file = file.txt;unlink($my_file); 32. PHP Workshop 32Review all 33. PHP Workshop 33Review all