Author: jpuyy

安装screen

#apt-get install screen

安装byobu

#apt-get install byobu

接下来主要讲screen Detached表示会话处于挂起状态，Attached表示有终端在连接会话，Dead状态为死掉状态 清理screen的Dead会话，可以查看到此会话的进程号，然后kill -9，之后再screen -wipe

[detached from 10054.pts-0.www]
jpuyy@www:~$ kill -9 10054
jpuyy@www:~$ screen -ls
There is a screen on:
 10054.pts-0.www (2012年03月03日 21时09分03秒) (Dead ???)
Remove dead screens with 'screen -wipe'.
1 Socket in /var/run/screen/S-jpuyy.

jpuyy@www:~$ screen -wipe
There is a screen on:
 10054.pts-0.www (2012年03月03日 21时09分04秒) (Removed)
1 socket wiped out.
No Sockets found in /var/run/screen/S-jpuyy.

screen 新建screen并登陆到其中 screen -t win 创建一个以win作为默认窗口标题的screen并登陆到其中 screen -list 列出screen列表 screen -wipe 清理僵死的screen窗口 screen -r [pid] 连接到当前无用户在连接的对应pid的screen，pid可以通过screen -list获得 screen -x [pid] 连接到对应pid的screen，不论当前有无用户已连接其中 screen窗口内部常用命令： 先按CTRL+a，然后松开再按下面的键： c 创建新的screen窗口并切换到其中 K 杀死当前screen窗口 ” 列出当前screen窗口列表 ‘ 输入screen窗口号码或名称的提示符 0 选择0号窗口 … 9 选择9号窗口 A 设置当前screen窗口的标题 d 断开与当前scree终端的连接 DD 断开与当前screen终端的连接并注销 –added in 20121204 用无线连接时，正在使用screen，突然网断了，然后重新连到服务器上

root@ibm:~# screen -r
There is a screen on:
 24643.pts-0.ibm (11/27/2012 07:50:06 PM) (Attached)
There is no screen to be resumed.

发现不能回到原来的screen，从网上查得使用如下命令，踢掉上次中断的用户，并接管screen：

screen -D -r <session-id>

如上面的例子就是 ：

screen -D -r 24643

使用node js版的shadowsocks时，会自动挂掉，所以把它放到screen中，用crontab每45分钟重开启一下

*/45 * * * * /usr/bin/killall screen; /usr/bin/screen -dmS node /usr/local/bin/node /usr/local/shadowsocks-nodejs/server.js

参考文章： http://www.ibm.com/developerworks/cn/linux/l-cn-screen/

使用screen翻屏

Ctrl+A, Esc 进入 C/P 模式，然后用Page Up/Down 翻页
还能用?<string> 查找

使用screen的时候，通用配置文件在/etc/screenrc，可以新建~/.screenrc从而使用定制化的screen配置。 add @2014-05-15 启动screen的时候，直接连接多个ssh，用tab区分

screen -dmS sshmulti -c sshmulti.conf

原理是将ssh的命令和名称写到sshmulti.conf，启动时指定配置文件，配置文件如下

escape ^Xx
autodetach      on      # default: on
crlf         off      # default: off
hardcopy_append   on      # default: off
startup_message   off      # default: on
termcap  xterm   'AF=\E[3%dm:AB=\E[4%dm'
terminfo xterm   'AF=\E[3%p1%dm:AB=\E[4%p1%dm'
vbell         off      # default: ???
defscrollback      1000      # default: 100
silencewait      15      # default: 30

caption always "%{wk}%?%-Lw%?%{bw}%n*%f %t%?(%u)%?%{wk}%?%+Lw%? %= %{= kw}%110`%109`%111`"
hardstatus string '%99`%{= kw} %100`%112`%= %102`%101`%114`%115`%108`%113`%119`%117`%118`%116`%106`%104`%103`%105`%107`%Y-%m-%d %0c:%s'

activity      "activity in %n (%t) [%w:%s]~"
bell         "bell     in %n (%t) [%w:%s]~"
pow_detach_msg   "BYE"
vbell_msg      " *beep* "

screen -t server88 ssh 192.168.1.88
screen -t server99 ssh 192.168.1.99

参考：http://askubuntu.com/questions/49245/start-multiple-apps-running-in-shells-split-in-one-console

有时在 screen 里会要看很长的历史，则需要把 buffer 加大，要看的时候按 ctrl-a 再按 {，再按 u 上翻, d 下翻

对 session 重命名

screen  -list
There are screens on:
        2580.pts-0.centos7-work (Detached)
        2478.pts-0.centos7-work (Detached)
2 Sockets in /var/run/screen/S-vagrant.
# 重命名 -S 当前名 -X sessionname 要修改的名字
screen -S 2580.pts-0.centos7-work -X sessionname backend-service

创建新的 tab

press Ctrl+A+c to create a new virtual console

切换

press Ctrl+A+n to switch to next tab
press Ctrl+A+p to switch to previous tab

CentOS 这样安装

yum install psmisc

看看我的vps上

init─┬─console-kit-dae───2*[{console-kit-da}]
├─courierlogger───authdaemond───5*[authdaemond]
├─2*[courierlogger───couriertcpd]
├─cron───4*[cron───sh───python]
├─dbus-daemon
├─7*[getty]
├─master─┬─pickup
│        ├─proxymap
│        ├─qmgr
│        └─tlsmgr
├─mongod───7*[{mongod}]
├─mysqld───20*[{mysqld}]
├─nginx───2*[nginx]
├─openvpn
├─php5-fpm───3*[php5-fpm]
├─pptpd
├─2*[python───5*[{python}]]
├─rsyslogd───3*[{rsyslogd}]
├─snmpd
├─sshd───sshd─┬─bash───top
│             └─bash───pstree
├─udevd───2*[udevd]
└─upstart-udev-br

pstree -p 可同时显示进程号

在centos 6.2 64bit 下面安装rtorrent方法：

cd /etc/yum.repos.d
wget http://yum.aclub.net/pub/linux/centos/6/umask/umask.repo
rpm --import http://yum.aclub.net/pub/linux/centos/6/umask/RPM-GPG-KEY-umask
yum install rtorrent screen

在个人文件夹中，创建需要的目录

cd ~
mkdir watch # 用于存放.torrent文件
mkdir ptfiles # 用于存放下载的资料
mkdir session # 存放session

编写适用于本人的rtorrent配置文件

vim ~/.rtorrent.rc

写入

# This is an example resource file for rTorrent. Copy to
# ~/.rtorrent.rc and enable/modify the options as needed. Remember to
# uncomment the options you wish to enable.
# Maximum and minimum number of peers to connect to per torrent.
min_peers = 40
max_peers = 100
# Same as above but for seeding completed torrents (-1 = same as downloading)
min_peers_seed = 10
max_peers_seed = 50
# Maximum number of simultanious uploads per torrent.
max_uploads = 15
# Global upload and download rate in KiB. "0" for unlimited.
download_rate = 0
upload_rate = 0
# Default directory to save the downloaded torrents.
directory = ./ptfiles
# Default session directory. Make sure you don't run multiple instance
# of rtorrent using the same session directory. Perhaps using a
# relative path?
session = ./session
# Watch a directory for new torrents, and stop those that have been
# deleted.
schedule = watch_directory,5,5,load_start=./watch/*.torrent
schedule = untied_directory,5,5,stop_untied=
# Close torrents when diskspace is low.
schedule = low_diskspace,5,60,close_low_diskspace=100M
# The ip address reported to the tracker.
#ip = 127.0.0.1
#ip = rakshasa.no
# The ip address the listening socket and outgoing connections is
# bound to.
#bind = 127.0.0.1
#bind = rakshasa.no
# Port range to use for listening.
port_range = 6890-6999
# Start opening ports at a random position within the port range.
#port_random = no
# Check hash for finished torrents. Might be usefull until the bug is
# fixed that causes lack of diskspace not to be properly reported.
check_hash = yes
# Set whetever the client should try to connect to UDP trackers.
#use_udp_trackers = yes
# Alternative calls to bind and ip that should handle dynamic ip's.
#schedule = ip_tick,0,1800,ip=rakshasa
#schedule = bind_tick,0,1800,bind=rakshasa
# Encryption options, set to none (default) or any combination of the following:
# allow_incoming, try_outgoing, require, require_RC4, enable_retry, prefer_plaintext
#
# The example value allows incoming encrypted connections, starts unencrypted
# outgoing connections but retries with encryption if they fail, preferring
# plaintext to RC4 encryption after the encrypted handshake
#
# encryption = allow_incoming,enable_retry,prefer_plaintext
# Enable DHT support for trackerless torrents or when all trackers are down.
# May be set to "disable" (completely disable DHT), "off" (do not start DHT),
# "auto" (start and stop DHT as needed), or "on" (start DHT immediately).
# The default is "off". For DHT to work, a session directory must be defined.
#
dht = auto
# UDP port to use for DHT.
#
# dht_port = 6881
# Enable peer exchange (for torrents not marked private)
#
# peer_exchange = yes
#
# Do not modify the following parameters unless you know what you're doing.
#
# Hash read-ahead controls how many MB to request the kernel to read
# ahead. If the value is too low the disk may not be fully utilized,
# while if too high the kernel might not be able to keep the read
# pages in memory thus end up trashing.
#hash_read_ahead = 10
# Interval between attempts to check the hash, in milliseconds.
#hash_interval = 100
# Number of attempts to check the hash while using the mincore status,
# before forcing. Overworked systems might need lower values to get a
# decent hash checking rate.
#hash_max_tries = 10

到这里，rtorrent已经配置完成，为了端口正常使用，centos的iptables里需加:

iptables -A INPUT -p tcp --dport 6890:6900 -j ACCEPT
iptables -A INPUT -p udp --dport 6890 -j ACCEPT

rtorrent完全基于文本并在终端中运行，不可能每时每刻都开tty。所以，配合screen来，效果很好(screen -dmS name cmd )

 screen -dmS rtorrent-name rtorrent

在rtorrent的界面，常执行的操作是

Ctrl-s

Start download. Runs hash first unless already done. 定位到一个种子后，会先检查hash开始下载，一般是自动下载的

Ctrl-d

Stop an active download or remove a stopped download，按一次暂停，再按一次删除此任务及torrent文件(不会删除对应的下载文件)

a/s/d 增大下载速度限制分别为 1/5/50 KB.
z/x/c 减少下载速度限制分别为 1/5/50 KB.
A/S/D 增大上传速度限制分别为 1/5/50 KB.
Z/X/C 减少上传速度限制分别为 1/5/50 KB.

Ctrl-q

Quit application   退出rtorrent

官方文档

https://wiki.archlinux.org/index.php/RTorrent

当正常下载之后，使用screen的如下组合键：

(ctrl + a ) +d

使当前screen会话detached，常用，简单的来说就是把rtorrent放入后台。

下载 magnet 链接：

https://openwares.net/2016/12/04/rtorrent-magnet-download/
load 加载输入 magnet 链接即可