如何在特定字符之前插入链接 - How to insert link before specific character

How to insert link before specific character

本文关键字：插入链接字符 | 更新日期: 2023-09-27

这是视频块文件，我从file_get_contents获得它并将其存储在我的变量中，现在我想对这个字符串进行一些更改，我想将我的url放在所有之前

n_

每个n_行的起始，如

http://example.com/n_1_0_0.ts?nimblesessionid=9142491

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:8
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5.005,
#EXTINF:5.005,
n_1_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_2_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_3_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_4_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_5_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_6_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_7_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_8_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_9_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_10_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_11_0_0.ts?nimblesessionid=9142491

非常简单的任务-使用preg_replace():

<?php
$txt = '#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:8
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5.005,
#EXTINF:5.005,
n_1_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_2_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_3_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_4_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_5_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_6_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_7_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_8_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_9_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_10_0_0.ts?nimblesessionid=9142491
#EXTINF:7.507,
n_11_0_0.ts?nimblesessionid=9142491';
// ^ means from beginning of string
// m modifier is using for multi line string - its combine with ^ modifier
// 
$txt = preg_replace("/^(n_)+/m",'http://example.com/$1',$txt);
#$txt = preg_replace("/^n_/m",'http://example.com/n_',$txt);
echo $txt;