Php: The best way to read large files _ PHP Tutorial

Php provides the best way to read large files. Php is the best way to read large files. php is the best way to read large files. we generally write all the files into the memory in one row instead of writing them into the memory. this will cause the php program to kill, the best way for php to read large files

Php reads large files in a row instead of writing all the files into the memory at a time. This will cause the php program to become stuck. The following is an example.

The code is as follows:

Read the last few rows of data from a large file: /** * Get the last $ n lines of the file * @ Param string $ filename File path * @ Param int $ n the last few rows * @ Return mixed false indicates an error occurred. if the request succeeds, a string is returned. */ Function FileLastLines ($ filename, $ n ){ If (! $ Fp = fopen ($ filename, 'r ')){ Echo "failed to open the file. Please check whether the file path is correct and the path and file name do not contain Chinese characters "; Return false; } $ Pos =-2; $ Eof = ""; $ Str = ""; While ($ n> 0 ){ While ($ eof! = "N "){ If (! Fseek ($ fp, $ pos, SEEK_END )){ $ Eof = fgetc ($ fp ); $ Pos -; } Else { Break; } } $ Str. = fgets ($ fp ); $ Eof = ""; $ N -; } Return $ str; } Echo nl2br(FileLastLines('sss.txt ', 4 )); /*** Get the last $ n line of the file * @ param string $ filename File path * @ param int $ n the last few lines * @ return mixed false indicates an error occurred, returns the string */function FileLastLines ($ filename, $ n) {if (! $ Fp = fopen ($ filename, 'r') {echo "failed to open the file. Please check whether the file path is correct and the path and file name do not contain Chinese characters"; return false ;} $ pos =-2; $ eof = ""; $ str = ""; while ($ n> 0) {while ($ eof! = "N") {if (! Fseek ($ fp, $ pos, SEEK_END) {$ eof = fgetc ($ fp); $ pos --;} else {break;} $ str. = fgets ($ fp); $ eof = ""; $ n --;} return $ str;} echo nl2br(FileLastLines('sss.txt ', 4 )); Function tail ($ fp, $ n, $ base = 5) { Assert ($ n> 0 ); $ Pos = $ n + 1; $ Lines = array (); While (count ($ lines) <= $ n ){ Try { Fseek ($ fp,-$ pos, SEEK_END ); } Catch (Exception $ e ){ Fseek (0 ); Break; } $ Pos * = $ base; While (! Feof ($ fp )){ Array_unshift ($ lines, fgets ($ fp )); } } Return array_slice ($ lines, 0, $ n ); } Var_dump (tail (fopen ("access. log", "r +"), 10 )); $ Fp = fopen ($ file, "r "); $ Line = 10; $ Pos =-2; $ T = ""; $ Data = ""; While ($ line> 0 ){ While ($ t! = "N "){ Fseek ($ fp, $ pos, SEEK_END ); $ T = fgetc ($ fp ); $ Pos --; } $ T = ""; $ Data. = fgets ($ fp ); $ Line --; } Fclose ($ fp ); Echo $ data

Using php to read large files, we generally extract all the files into the memory in one row instead of writing them into the memory. this will cause the php program to become stuck ,...