$_FILES :
$_FILES : This super global Variable is used to handle File uploading in Server
Files can be of Any Type
1. Binary
2. Non Binary File
Example of Binary
Media Files mp3,mp4,pdf,zipped,or any other MIME Type
Example of Non Binary
All text format Files are Non Binary Files
.tmp
.log
.txt
.dat
.doc
.csv
.html Non Binary
.xml Non Binary
Uploading Means :
Read from One source and write One Another Source Read from One Destination and Write to Another Destination.
Copy and Move
Copy : first create the File
Read the from 1 File
write Another 2-File
Memory Release of File Pointer
In C Langauge
File* fp1;
File* fp2;
fp1=&File;
fp2=&File;
fp1=fopen("c:/something.txt",r);
fp2=fopen("d:/something.txt",w);
while($ch=fread(fp1)!=EOL){
fwrite(fp2,$ch)
}
fclose(fp1);
fclose(fp2);
Move :
Copy : first create the File
Read the from 1 File
write Another 2-File
Memory Release of File-2 Pointer
fseek(-1)
Steps How to upload files on server
Internal Working:
When ever we try to upload any file the a upload request is generated and file pointer is intialised
Who Intialised the File Pointer :
Inbuilt Server is Responsible for Intialising the File Pointer
1. Apache
2. PHP Cli Server
By default file pointer has source Address of tmp folder location in server
folder of Any server
Apache : tmp Root
php Inbuilt Server : php tmp folder
What is this tmp folder
it is default folder where every file handling is performed by server like storing file based session by file name sess_....
2. using any file with .tmp extension
Such path is defined inside php.ini file
Now the file which is to be uploaded from browser required key parameters
1. file_uploads=on in ini setting of server
2. Path should be available to tmp folder
upload_tmp_dir=
define the path
Note : in ini files ; means disable to enable directive remove ;
in httpd.conf # means disabled to enable #remove hash
3. file uploading in browser is now ready
steps for code
----------------
<form method="post" enctype="multipart/form-data">
<input type="file" name="xyz..">
<input type="submit">
Server Side Code
print_r($_FILES);
It is two dimensional
name key : name of file
tmp_name : file address of tmp folder
error : it show the error if happend during upload
size: it give the total memory reserved by tmp file
type : mime Type
Validating File Uploads
------------------------
Loop Hole : error is used to detect Error but this error is related to processing or Illegal Error But not valid or used defined error.
$filename = $_FILES['keyname']['name'];
$error = $_FILES['keyname']['error']; #Processing Error
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