Bagaimana membaca baris tertentu dari file di php?

This goes out to Leigh Purdie (5 years ago) and also Dade Brandon (4 months ago)

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:

$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=stream_get_line($fp,65535,"\n")) { 1; } fclose($fp);'

real    0m1.482s
user    0m1.616s
sys    0m0.152s

$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=fgets($fp,65535)) { 1; } fclose($fp);'

real    0m7.281s
user    0m7.392s
sys    0m0.136s

My Results:

$  time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=stream_get_line($fp,65535,"\n")) { 1; } fclose($fp);'

real    0m0.341s
user    0m0.352s
sys    0m0.148s

$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=fgets($fp,65535)) { 1; } fclose($fp);'

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_0

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_1

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_2

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_3

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_4

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_5

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_6

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_7

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_8

So i say Leigh posting and though omg i need to change all my fgets to stream_get_line. Then i ran the tests as shown in Leigh Purdie comment His results:_9

$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=stream_get_line($fp,65535,"\n")) { 1; } fclose($fp);'0

$ time yes "This is a test line" | head -1000000 | php -r '$fp=fopen("php://stdin","r"); while($line=stream_get_line($fp,65535,"\n")) { 1; } fclose($fp);'1

Diberi referensi file, temukan jumlah baris dalam file ini menggunakan PHP. Ada total 3 pendekatan untuk menyelesaikan ini

tes. txt. File ini digunakan untuk menguji semua kode PHP berikut

Geeks
For
Geeks

Pendekatan 1. Muat seluruh file ke dalam memori dan kemudian gunakan fungsi count() untuk mengembalikan jumlah baris dalam file ini

Contoh

PHP

<?php

    $filePath ="test.txt";

3

3

3

3

3

3

3

Keluaran

3

Pendekatan ini memuat seluruh file ke dalam memori yang dapat menyebabkan masalah kelebihan memori

Pendekatan 2. Di sini kita akan memuat hanya satu baris file pada satu waktu yang lebih baik daripada pendekatan pertama. Fungsi PHP fopen() digunakan untuk membuka file atau URL. Fungsi PHP fgets() digunakan untuk mengembalikan baris dari file terbuka. Fungsi fclose() digunakan untuk menutup pointer file

Contoh

PHP

<?php

    $filePath="test.txt";

3

3

3

3

3

3

3

3

3

    <?php1<?php2<?php3

3

3

________78______7<?php8 =    0

3

3

3

________78______7

3

    ________79______8

    _9

    $filePath1

3

3

    _9

3

3

3

Keluaran

3

Bagaimana jika file 1GB hanya memiliki satu baris di dalamnya. Kode ini akan memuat seluruh 1GB data yang dapat menyebabkan masalah kelebihan memori

Pendekatan 3. Kami hanya akan memuat ukuran data tertentu ke dalam memori. Kami tidak peduli dengan jeda baris pada saat memuat. Kami akan mengulangi data yang dimuat untuk menghitung jumlah jeda baris di dalamnya

Contoh

PHP

<?php

    $filePath="test.txt";

3

3

3

3

3

3

3

3

    _9

    <?php1<?php2<?php3

3

3

<?php7;7

________78______7<?php8 =    0

3

3

3

3

<?php7

3

<?php7

3

________78______7

3

3

3

3

    ________79______8

    _9

    $filePath1

3

3

    _9

3

3

3

Keluaran

3

Ini adalah pendekatan yang lebih baik dalam hal ruang tetapi, perhatikan bahwa kami mengulangi data kami dua kali Jadi, waktu yang dibutuhkan akan menjadi dua kali lipat

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