请注意，通过以下任何答案，您将违反YouTube的服务条款（TOS）。特别是第5.B节：
内容按原样提供给您。您只能根据本服务的提供功能和这些服务条款的规定，以信息和个人使用为目的访问内容。除非YouTube在该内容的服务上显示“下载”或类似链接，否则您不得下载任何内容。未经YouTube或内容的相应许可方事先书面同意，您不得复制、翻印、分发、传输、广播、展示、销售、授权或以其他方式利用任何内容进行其他任何目的。YouTube及其许可方保留在服务和内容中未明示授予的所有权利。
从官方网站安装：
sudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl
这个软件也可以在Ubuntu仓库中找到，但你经常需要用sudo youtube-dl -U命令来保持它的最新。
安装和升级方法（使用pip）：/
sudo -H pip install --upgrade youtube-dl
使用方法：
youtube-dl YouTube-(or-other-website)-video-linkaptitude，你可以使用apt-get代替。还请注意，在运行sudo aptitude install ...或sudo apt-get install ...命令之前，应该先运行sudo aptitude update或sudo apt-get update。 - Eliah Kaganapt-get代替。 - Rahul Virparasudo youtube-dl -U。 - bohdan_trotsenkoyoutube-dl :p - Thomassudo add-apt-repository ppa:nilarimogard/webupd8 -y ... sudo apt-get update ... sudo apt-get dist-upgrade... - Sortersudo pip install youtube-dl。@modosansreves我强烈不同意，程序不应该干扰由软件包管理器安装的东西。下次官方仓库升级时，dpkg可能会因为修改的文件而出现问题。 - alexiaapt-get安装无法从YouTube下载视频。但是pip安装了一个更近期的youtube-dl版本，可以正常工作。此外，请参阅@Prateek Joshi的答案和@nyuszika7h的评论。 - Paul Rougieuxsudo curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl
sudo chmod a+rx /usr/local/bin/youtube-dl
sudo -H pip install --upgrade youtube-dl
sudo apt-get install youtube-dl
youtube-dl [VIDEO_LINK]
要了解更多高级选项，请运行
man youtube-dl
或者查看文档。
对于Firefox用户：
您可以在Firefox中安装Video DownloadHelper插件，并下载任何嵌入的对象，包括YouTube视频。
apt-get安装的youtube-dl版本较旧，无法正常工作。根据手动安装说明，按照此处所述使用wget进行安装是有效的。 - Nagabhushan S N
phonon-backend-vlc。 - camelCaseD
youtube.com 前面添加 ss 并按下 Enter ↵。
sudo apt-get install wget
#!/usr/bin/perl -T
use strict;
use warnings;
#
## Calomel.org ,:, Download YouTube videos and music using wget
## Script Name : youtube_wget_video.pl
## Version : 0.38
## Valid from : March 2014
## URL Page : https://calomel.org/youtube_wget.html
## OS Support : Linux, Mac OSX, OpenBSD, FreeBSD or any system with perl
# `:`
## Two arguments
## $1 YouTube URL from the browser
## $2 Prefix to the file name of the video (optional)
#
############ options ##########################################
# Option: what file type do you want to download? The string is used to search
# in the YouTube URL so you can choose mp4, webm, avi or flv. mp4 seems to
# work on the most players like Android, iPod, iPad, iPhones, VLC media player
# and MPlayer.
my $fileType = "mp4";
# Option: what visual resolution or quality do you want to download? List
# multiple values just in case the highest quality video is not available, the
# script will look for the next resolution. You can choose "highres" for 4k,
# "hd1080" for 1080p, "hd720" for 720p, "itag=18" which means standard
# definition 640x380 and "itag=17" which is mobile resolution 144p (176x144).
# The script will always prefer to download the highest resolution video format
# from the list if available.
my $resolution = "hd720,itag=18";
# Option: How many times should the script retry the download if wget fails for
# any reason? Do not make this too high as a reoccurring error will just hit
# YouTube over and over again.
my $retryTimes = 5;
# Option: do you want the resolution of the video in the file name? zero(0) is
# no and one(1) is yes. This option simply puts "_hd1080.mp4" or similar at the
# end of the file name.
my $resolutionFilename = 0;
# Option: turn on DEBUG mode. Use this to reverse engineering this code if you are
# making changes or you are building your own YouTube download script.
my $DEBUG=0;
#################################################################
## Initialize retry loop and resolution variables
$ENV{PATH} = "/bin:/usr/bin:/usr/local/bin";
my $prefix = "";
my $retry = 1;
my $retryCounter = 0;
my $resFile = "unknown";
my $user_url = "";
my $user_prefix = "";
## Collect the URL from the command line argument
chomp($user_url = $ARGV[0]);
my $url = "$1" if ($user_url =~ m/^([a-zA-Z0-9\_\-\&\?\=\:\.\/]+)$/ or die "\nError: Illegal characters in YouTube URL\n\n" );
## Declare the user defined file name prefix if specified
if (defined($ARGV[1])) {
chomp($user_prefix = $ARGV[1]);
$prefix = "$1" if ($user_prefix =~ m/^([a-zA-Z0-9\_\-\.\ ]+)$/ or die "\nError: Illegal characters in filename prefix\n\n" );
}
## Retry getting the video if the script fails for any reason
while ( $retry != 0 && $retryCounter < $retryTimes ) {
## Download the html code from the YouTube page suppling the page title and the
## video URL. The page title will be used for the local video file name and the
## URL will be sanitized and passed to wget for the download.
my $html = `wget -4Ncq -e convert-links=off --keep-session-cookies --save-cookies /dev/null --no-check-certificate "$url" -O-` or die "\nThere was a problem downloading the HTML file.\n\n";
## Format the title of the page to use as the file name
my ($title) = $html =~ m/<title>(.+)<\/title>/si;
$title =~ s/[^\w\d]+/_/g or die "\nError: we could not find the title of the HTML page. Check the URL.\n\n";
$title =~ s/_youtube//ig;
$title =~ s/^_//ig;
$title = lc ($title);
$title =~ s/_amp//ig;
## Collect the URL of the video from the HTML page
my ($download) = $html =~ /"url_encoded_fmt_stream_map"(.*)/ig;
# Print all of the separated strings in the HTML page
print "\n$download\n\n" if ($DEBUG == 1);
# This is where we look through the HTMl code and select the file type and
# video quality.
my @urls = split(',', $download);
OUTERLOOP:
foreach my $val (@urls) {
# print "\n$val\n\n";
if ($val =~ /$fileType/) {
my @res = split(',', $resolution);
foreach my $ress (@res) {
if ($val =~ /$ress/) {
print "\n\nGOOD\n\n" if ($DEBUG == 1);
print "$val\n" if ($DEBUG == 1);
$resFile = $ress;
$resFile = "sd640" if ( $ress =~ /itag=18/ );
$resFile = "mobil176" if ( $ress =~ /itag=17/ );
$download = $val;
last OUTERLOOP;
}
}
}
}
## Clean up the URL by translating unicode and removing unwanted strings
$download =~ s/\:\ \"//;
$download =~ s/%3A/:/g;
$download =~ s/%2F/\//g;
$download =~ s/%3F/\?/g;
$download =~ s/%3D/\=/g;
$download =~ s/%252C/%2C/g;
$download =~ s/%26/\&/g;
$download =~ s/sig=/signature=/g;
$download =~ s/\\u0026/\&/g;
$download =~ s/(type=[^&]+)//g;
$download =~ s/(fallback_host=[^&]+)//g;
$download =~ s/(quality=[^&]+)//g;
## Clean up the URL
my ($youtubeurl) = $download =~ /(http?:.+)/;
## URL title additon
my ($titleurl) = $html =~ m/<title>(.+)<\/title>/si;
$titleurl =~ s/ - YouTube//ig;
$titleurl =~ s/ /%20/ig;
## Combine the YouTube URL and title string
$download = "$youtubeurl\&title=$titleurl";
## A bit more cleanup as YouTube
$download =~ s/&+/&/g;
$download =~ s/&itag=\d+&signature=/&signature=/g;
## Combine file variables into the full file name
my $filename = "unknown";
if ($resolutionFilename == 1) {
$filename = "$prefix$title\_$resFile.$fileType";
}
else {
$filename = "$prefix$title.$fileType";
}
## Process check: Are we currently downloading this exact same video? Two of the
## same wget processes will overwrite themselves and corrupt the video.
my $running = `ps auwww | grep [w]get | grep -c "$filename"`;
print "\nNumber of the same wgets running: $running\n" if ($DEBUG == 1);
if ($running >= 1)
{
print "\nAlready $running process, exiting." if ($DEBUG == 1);
exit 0;
};
## Print the long, sanitized YouTube URL for testing and debugging
print "\n$download\n" if ($DEBUG == 1);
## Print the file name of the video collected from the web page title for us to see on the cli
print "\n Download: $filename\n\n";
## Background the script. Use "ps" if you need to look for the process
## running or use "ls -al" to look at the file size and date.
fork and exit;
## Download the video
system("wget", "-4Ncq", "-e", "convert-links=off", "--load-cookies", "/dev/null", "--tries=10", "--timeout=20", "--no-check-certificate", "$download", "-O", "$filename");
## Print the error code of wget
print " error code: $?\n" if ($DEBUG == 1);
## Exit Status: Check if the file exists and we received the correct error code
## from system call. If the download experienced any problems the script will run again and try
## continue the download till the file is downloaded.
if ($? == 0 && -e "$filename" && ! -z "$filename")
{
print " Finished: $filename\n\n" if ($DEBUG == 1);
$retry = 0;
}
else
{
print STDERR "\n FAILED: $filename\n\n" if ($DEBUG == 1);
$retry = 1;
$retryCounter++;
sleep $retryCounter;
}
} # while
#### EOF #####
youtube_wget.pl。chmod 755 youtube_wget.pl
./youtube_wget.pl http://www.youtube.com/watch?v=ejkm5uGoxs4
将YouTube的URL更改为您的YouTube视频URL。
保存位置：视频将保存在当前目录中。
wget，因为他询问了如何以特定的方式使用它。 - Radu Rădeanuwget的脚本（并向用户公开完全不同的接口），我会选择 youtube-dl答案。youtube-dl更加强大。 - Blacklight Shiningps -aux | grep wget来检查下载是否完成。 - suhailvs使用这个易于使用的命令行工具，我们可以从YouTube或其他流媒体网站下载免费内容。
cclive主要是一个“视频下载工具”，但它也可以与视频播放器软件（如“mplayer”）一起使用，用于观看流媒体视频，而不是Adobe Flash播放器。
要从给定位置下载视频（在YouTube上按下“分享”按钮以获取视频的URL）。复制此链接，并在终端中使用以下命令执行clive：
cclive -s best http://youtu.be/D6z6hn6wZlg
还有许多其他选项可控制下载行为，包括选择下载格式的选项，所有这些选项都在 manpage 中有详细说明。我们还可以从文件中排队一系列的 URL。
(将 -f 更改为 -s；-f 已被弃用)。
仅适用于 Ubuntu 18.10 及更早版本。
由于我认为我的答案在这里更加合适，所以我将在这里提供便利。
你可以使用flashgot，它是Firefox的一个插件，我发现它非常有用，可以从YouTube和其他网站下载视频。（然而，你仍然需要在浏览器中安装Flash插件，以使视频能够被flashgot检测到。）
从Mozilla官方插件站点安装flashgot并重启Firefox。确保插件已启用；通过菜单 工具 → 扩展 → 插件 进行检查。在扩展选项卡中的 flashgot 条目中，您还可以设置一些首选项。
导航到您的YouTube视频，并在YouTube视频设置中设置质量，然后开始播放视频几秒钟，然后暂停。
在YouTube页面中右键单击，选择flashgot media；可能会有多个视频；要么同时下载两者，要么选择较大的文件尺寸（这将是更高质量的视频）。您可以使用浏览器的下载管理器或通过flashgot options设置另一个程序。
Ctrl + N或点击媒体>打开网络串流...）Ctrl + I或右键点击视频区域>工具>媒体信息）4k下载器！除了从URL下载视频之外，它还可以下载整个播放列表，并在需要时将其转换为MP3或其他格式。
我用它很久了，它简单易用，而且还有适用于Ubuntu的图形用户界面（GUI）。