Php ultra-fast and efficient statistics on the number of large file lines

This article mainly introduces php's ultra-fast and efficient statistics on the number of large file lines. For more information, see use php to obtain the number of file lines, this is not applicable to large files. Generally, large files use the while clause to perform row-by-row statistics cyclically, which is too slow.

The fastest way is to perform multi-row statistics, read N bytes each time, and then count the number of rows, which is much more efficient than row-by-row statistics.

Test results: the file size is 3.14 GB.

1st times: line: 13214810, time: 56.2779 s;
2nd times: line: 13214810, time: 49.6678 s;

/** Calculate the number of lines of files efficiently * @ author axiang */function count_line ($ file) {$ fp = fopen ($ file, "r"); $ I = 0; while (! Feof ($ fp) {// Read 2 M if ($ data = fread ($ fp, 1024*1024*2) each time )) {// calculate the number of rows read $ num = substr_count ($ data, "\ n"); $ I + = $ num ;}} fclose ($ fp ); return $ I ;}

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