Php functions for detecting file types

Php functions for detecting file types

// Check the file type // By http://bbs.it-home.org Function checkFileType ($ filename ){ // File header $ _ Typecode = array ( '000000', // PDF '123', // .docx,.xlsx,.pptx,. potx,. vsdx,. odt '20140901', // .doc,.xls,.ppt,. sealing,. pot,. wps,. dps,. et ); $ File = fopen ($ filename, "rb "); // Contents = stream_get_contents ($ file ); // $ Contents = fread ($ file, filesize ($ filename )); $ Bin = fread ($ file, 2); // read-only 2 bytes Fclose ($ file ); $ StrInfo = @ unpack ("C2chars", $ bin); // C is an unsigned integer. all searched online is c, which is a signed integer. Therefore, negative numbers are generated. $ TypeCode = intval ($ strInfo ['chars1']. $ strInfo ['chars2']); Exec ("file $ filename", $ output, $ return_var); // use the linux system command file to determine the type of the uploaded file, mainly to determine the txt and rtf file types $ Pattern = '/text,/'; // both the rtf and txt files are detected as text $ _ Count = preg_match ($ pattern, strrchr ($ output [0], ":"); Echo $ typeCode; If (in_array ($ typeCode, $ _ typecode) | $ _ count = 1 ){ Return true; } Else { Return false; } } ?>