Question

我正在尝试消除网页特定部分中包含的JSON之前和之后的所有内容，以便将其发送到PHP脚本。我尝试了多种方法来摆脱容器的内容，但到目前为止，所有方法都失败了，其中包括一种出于相关目的而使用完全相同的语法的方法：

我需要删除开头和结尾两个星号（**）之间的字符：

**var songs = [**{"timestamp":1555176393000,"title":"Enter Sandman","trackId":"ba_5cbb546d-5c1c-490e-9908-761b89dd5166","artist":"Metallica","artistId":"52_65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab","album":"Metallica","albumId":"d0_6e729716-c0eb-3f50-a740-96ac173be50d","npe_id":"3cc5fe24d0ffcbb9152d861f27ae801660"},{"timestamp":1555176702000,"title":"Start Me Up","trackId":"76_d0b86399-11e5-4d11-b4fe-ce4b3f9a4736","artist":"The Rolling Stones","artistId":"1b_b071f9fa-14b0-4217-8e97-eb41da73f598","album":"Tattoo You","albumId":"d1_778b345b-e8a1-4054-b5ba-c611d3fda421","npe_id":"f0dc0ab12ef99a6e0087cad12886509b7b"},{"timestamp":1555176909000,"title":"Fame","trackId":"4e_cdef4b88-7314-431a-9cdd-d457296a65b7","artist":"David Bowie","artistId":"ab_5441c29d-3602-4898-b1a1-b77fa23b8e50","album":"Best of Bowie","albumId":"21_3709ee5a-d087-370f-afb4-f730092c7a94","npe_id":"2b8b3a170baa77125891d72a0474d3343a"},{"timestamp":1555177158000,"title":"Rocket","trackId":"34_aa5b9053-849e-4788-972f-7941303175b6","artist":"Def Leppard","artistId":"c1_7249b899-8db8-43e7-9e6e-22f1e736024e","album":"Hysteria","albumId":"06_de5cf055-d875-41f8-9261-89b11b7ff145","npe_id":"0d87b580f140a85feaebc7d77f75db2a3d"},{"timestamp":1555177826000,"title":"Mama, I'm Coming Home","trackId":"cb_e5b09171-9527-4d24-8ab6-1e922fdd66d3","artist":"Ozzy Osbourne","artistId":"4b_8aa5b65a-5b3c-4029-92bf-47a544356934","album":"No More Tears","albumId":"66_8f3d5a65-036c-3260-b9bb-36f1d0d80c11","npe_id":"6b766464fe945f275bf478192dcd33cfdc"},{"timestamp":1555178076000,"title":"Gold Dust Woman","trackId":"a4_ef8c1eca-f344-4bfb-82ea-763aa8aeaad9","artist":"Fleetwood Mac","artistId":"66_bd13909f-1c29-4c27-a874-d4aaf27c5b1a","album":"2010-01-08: The Rock Boat X, Lido Deck, Carnival Inspiration","albumId":"80_4f229af0-2afc-431d-87ff-f7f6af66268e","npe_id":"f6417d98fd1fefcca227d82a8ac9b84197"},{"timestamp":1555178363000,"title":"With or Without You","trackId":"79_6b9a509f-6907-4a6e-9345-2f12da09ba4b","artist":"U2","artistId":"26_a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432","album":"The Joshua Tree","albumId":"0c_d287c703-5c25-3181-85d4-4d8c1a7d8ecd","npe_id":"23b19420196b28e2156ecda87c11b882e0"},{"timestamp":1555178654000,"title":"Who Are You","trackId":"7d_431b9746-c6ec-489d-9199-c83676171ae8","artist":"The Who","artistId":"22_f2fa2f0c-b6d7-4d09-be35-910c110bb342","album":"Who Are You","albumId":"40_b255da2c-6583-35f9-95e3-ef5f9c14e868","npe_id":"e01896f74f24968bb7727eaafbf6250b8f"},{"timestamp":1555179031000,"title":"Authority Song","trackId":"31_f5ff19f7-95f3-4a22-8996-3788c264e0b8","artist":"John Mellencamp","artistId":"4d_0aad6b52-fd93-4ea4-9c5d-1f66e1bc9f0a","album":"Words & Music: John Mellencamp's Greatest Hits","albumId":"9e_1240c510-7015-4484-baac-ce17f5277ea1","npe_id":"244785e3b1d75effb9fdecbb6df76b009f"},{"timestamp":1555179256000,"title":"Touch Me","trackId":"9d_1dd1f86c-2120-45f3-ac9f-3c87257fe414","artist":"The Doors","artistId":"13_9efff43b-3b29-4082-824e-bc82f646f93d","album":"The Soft Parade","albumId":"db_c29d7552-b5df-42b8-aae7-03d1e250cb3a","npe_id":"1b5d155eb2eeee6fc1fdb50a94b100669c"}]**; <ol class="songs tracks"></ol>**

这是目前产生上述结果的shell脚本：

#!/bin/sh
curl -v --silent http://player.listenlive.co/41851/en/songhistory >/var/tmp/wklh$1.a.txt
pta=`cat /var/tmp/wklh$1.a.txt | grep songs > /var/tmp/wklh$1.b.txt`
ptb=`cat /var/tmp/wklh$1.b.txt | sed -n -e '/var songs = /,/; <span title/ p' > /var/tmp/wklh$1.c.txt`
ptc=`cat /var/tmp/wklh$1.c.txt | grep songs > /var/tmp/wklh$1.d.txt`
#ptd=`cat /var/tmp/wklh$1.d.txt | sed -i 's/var songs = [//g' /var/tmp/wklh$1.d.txt`
#ptd=`cat /var/tmp/wklh$1.d.txt | sed -i 's/}]; <ol class="songs tracks"></ol>//g' /var/tmp/wklh$1.d.txt`

json=`cat /var/tmp/wklh$1.d.txt`
echo $json

metadata=`php /etc/asterisk/scripts/music/wklh.php $json`
echo $metadata

注释掉的行是我试图用来删除无关内容的内容，因为每次都是可以预测的。但是，如果未注释，则会出现以下错误：

sed: -e expression #1, char 18: unterminated `s' command
sed: -e expression #1, char 38: unknown option to `s'

我已经检查了sed语句，但是我在这里使用它和在其他有效的Shell脚本中找不到任何差异。

这里实际上是否存在语法错误（或不允许使用的字符）？还是有更好的方法可以做到这一点？

Answer 1

您的shell脚本有严重问题。

语法

variable=`commands`

获取commands的输出并将其分配给variable。但是在每种情况下，您都将所有输出重定向到一个文件。因此该变量将始终为空。

除非您出于问题中未说明的原因而需要临时文件（例如，也许能够检查每个临时文件中为监视报告而获得的输出字节数之类的东西），否则使用管道会更好。

#!/bin/sh
curl -v --silent http://player.listenlive.co/41851/en/songhistory |
grep songs |
sed -n -e '/var songs = /,/; <span title/ p' |
grep songs |
php /etc/asterisk/scripts/music/wklh.php

这也消除了useless uses of cat和useless uses of echo，因此也巧合地删除了quoting errors。 grep x | sed -n 's/y/z/p'是useless use of grep，可以很容易地重构为sed -n '/x/s/y/z/p'

Answer 2

方括号特别适用于sed。逃脱它们。

s/var songs = \[//g

如果使用斜杠/作为正则表达式定界符，它将变得很特殊。要么转义它，要么使用其他定界符。

s/}]; <ol class="songs tracks"><\/ol>//g
s|}]; <ol class="songs tracks"></ol>||g

Answer 3

如果您的数据位于“ d”文件中，请尝试使用gnu sed，

sed -Ez 's/^\*\*[^\*]+\*\*(.+)]\*\*[^\*]+\*\*\s*$/\1/' d

也删除最后一个]，以正确平衡Json

如何使用Shell脚本截断无关的输出？

3 个答案: