How to change the order of lines in a file?

SOTVM2020-01-12 12:03:06

linux

SOTVM, 2020-01-12 12:03:06

I do not want to reinvent the wheel,
maybe someone has already solved a similar problem.

we have a youtube.m3u8 playlist

#EXTM3U
#EXTINF:0,ПАВЛИК 4 сезон 10 серия
https://www.youtube.com/watch?v=z4oMY9Q0HOg
#EXTINF:0,ПАВЛИК 4 сезон 9 серия
https://www.youtube.com/watch?v=Vk_nZ8_V5ko
#EXTINF:0,ПАВЛИК 4 сезон 8 серия
https://www.youtube.com/watch?v=LB5VAm2b4iA
#EXTINF:0,ПАВЛИК 4 сезон 7 серия
https://www.youtube.com/watch?v=kjJMTnU9GCg
#EXTINF:0,ПАВЛИК 4 сезон 6 серия
https://www.youtube.com/watch?v=hGsITAB76_4
#EXTINF:0,ПАВЛИК 4 сезон 5 серия
https://www.youtube.com/watch?v=MCJUj3EgiYk
#EXTINF:0,ПАВЛИК 4 сезон 4 серия
https://www.youtube.com/watch?v=M-VGl5lxyC8
#EXTINF:0,ПАВЛИК 4 сезон 3 серия
https://www.youtube.com/watch?v=cNwUqDbXLiY
#EXTINF:0,ПАВЛИК 4 сезон 2 серия
https://www.youtube.com/watch?v=jHYW6mq7D24
#EXTINF:0,ПАВЛИК 4 сезон 1 серия
https://www.youtube.com/watch?v=RBDiRbE4yoI
#EXTINF:0,ПАВЛИК 4 сезон - Трейлер
https://www.youtube.com/watch?v=pjJfQ7Nw568

you need to change the video order in it, 10-5 4 3 2 1 by 1 2 3 4 5-10 I
present such an algorithm
1) copy the 1st line of the source file list.m3u8 to new.list.m3u8
delete the 1st line from the source .
2) copy the last 2 lines of the list.m3u8 file and >> add to new.list.m3u8
delete the last 2 lines of the list.m3u8 file
3) repeat point 2) while there is something to copy in the source file

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3 answer(s)

vreitech, 2020-01-12
@sotvm

perl -i -0ne 's/#EXTM3U\n//g;s/(#EXTINF:.*)\n(http.*)/\2\n\1/g;$_.="#EXTM3U\n";print join("\n",reverse(split("\n")))' ./youtube.m3u8

Sergey Karbivnichy, 2020-01-12
@hottabxp

If I understand correctly, then the tac command (reverse cat) will help you.
tac list.m3u8 > list2.m3u8
https://www.youtube.com/watch?v=pjJfQ7Nw568
#EXTINF:0,ПАВЛИК 4 сезон - Трейлер
https://www.youtube.com/watch?v=RBDiRbE4yoI
#EXTINF:0,ПАВЛИК 4 сезон 1 серия
https://www.youtube.com/watch?v=jHYW6mq7D24
#EXTINF:0,ПАВЛИК 4 сезон 2 серия
https://www.youtube.com/watch?v=cNwUqDbXLiY
#EXTINF:0,ПАВЛИК 4 сезон 3 серия
https://www.youtube.com/watch?v=M-VGl5lxyC8
#EXTINF:0,ПАВЛИК 4 сезон 4 серия
https://www.youtube.com/watch?v=MCJUj3EgiYk
#EXTINF:0,ПАВЛИК 4 сезон 5 серия
https://www.youtube.com/watch?v=hGsITAB76_4
#EXTINF:0,ПАВЛИК 4 сезон 6 серия
https://www.youtube.com/watch?v=kjJMTnU9GCg
#EXTINF:0,ПАВЛИК 4 сезон 7 серия
https://www.youtube.com/watch?v=LB5VAm2b4iA
#EXTINF:0,ПАВЛИК 4 сезон 8 серия
https://www.youtube.com/watch?v=Vk_nZ8_V5ko
#EXTINF:0,ПАВЛИК 4 сезон 9 серия
https://www.youtube.com/watch?v=z4oMY9Q0HOg
#EXTINF:0,ПАВЛИК 4 сезон 10 серия
#EXTM3U

Well, you need to modify a little!

Vadim Priluzkiy, 2020-01-12
@Oxyd

head -n 1 list.m3u8 > new.list.m3u8 ; tac list.m3u8 | head -n -1 >> new.list.m3u8