更新至 2018/10

Provider Primary DNS Server Secondary DNS Server
Level31 209.244.0.3 209.244.0.4
Verisign2 64.6.64.6 64.6.65.6
Google3 8.8.8.8 8.8.4.4
Quad94 9.9.9.9 149.112.112.112
DNS.WATCH5 84.200.69.80 84.200.70.40
Comodo Secure DNS 8.26.56.26 8.20.247.20
OpenDNS Home6 208.67.222.222 208.67.220.220
Norton ConnectSafe7 199.85.126.10 199.85.127.10
GreenTeamDNS8 81.218.119.11 209.88.198.133
SafeDNS9 195.46.39.39 195.46.39.40
OpenNIC10 69.195.152.204 23.94.60.240
SmartViper 208.76.50.50 208.76.51.51
Dyn 216.146.35.35 216.146.36.36
FreeDNS11 37.235.1.174 37.235.1.177
Alternate DNS12 198.101.242.72 23.253.163.53
Yandex.DNS13 77.88.8.8 77.88.8.1
UncensoredDNS14 91.239.100.100 89.233.43.71
Hurricane Electric15 74.82.42.42
puntCAT16 109.69.8.51
Neustar17 156.154.70.1 156.154.71.1
Cloudflare18 1.1.1.1 1.0.0.1
Fourth Estate19 45.77.165.194
CleanBrowsing20 185.228.168.9 185.228.169.9

 

Refer: https://www.lifewire.com/free-and-public-dns-servers-2626062

今天在研究Linux下增量备份的时候,发现了一个非常Genius的命令。

用这个命令即可以做到增量备份,又可以最少量的占用硬盘空间。

 

rm -rf backup.3
mv backup.2 backup.3
mv backup.1 backup.2
cp -al backup.0 backup.1
rsync -a --delete source_directory/ backup.0/

 

多的懒得写了,大家自己体会吧。:D

 

Refer:http://www.admin-magazine.com/Articles/Using-rsync-for-Backups/

最近因转换视频格式需要,研究了一下目前的视频格式转换工具。
发现下面几个比较顺手的:

    1. Adobe Media Encoder
      很强大的视频转换工具,支持显卡加速,只是需要$$$
    2. Any Video Converter Free
      转换手机视频的利器,转出来的视频格式比Handbrake要小。当然画质就稍微差点,720P的电影,一部转下来大概有1GB大小。免费
    3. Handbrake
      老牌的免费视频转换工具,支持H265。转出来的画质不错。

Here are steps to setup a user and allow the user access only via FTP (i.e. no SSH) and also limit access to a specific (user home) directory on proftpd:

1. Add new user: adduser newusername
2. Set password: passwd newusername
3. Modify user home directory from default to a new folder:

usermod -d /target/directory username

4. Edit shells file: vi /etc/shells and add /dev/null at the end
5. Modify newusername entry in the passwd file: vi /etc/passwd to add /./ before the newusername so that the entry looks like this:

newusername:x:502:502::/home/ftp/./newusernamehomedirectory/:/dev/null

6. Edit /etc/proftpd/proftpd.conf file and uncomment the line DefaultRoot ~

grep -rnw '/path/to/somewhere/' -e 'pattern'
  • -r or -R is recursive,
  • -n is line number, and
  • -w stands for match the whole word.
  • -l (lower-case L) can be added to just give the file name of matching files.

Along with these, --exclude--include--exclude-dir flags could be used for efficient searching:

  • This will only search through those files which have .c or .h extensions:
    grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"
    
  • This will exclude searching all the files ending with .o extension:
    grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"
    
  • For directories, it’s possible to exclude a particular directory(ies) through --exclude-dirparameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/:
    grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"
    

This works very well for me, to achieve almost the same purpose like yours.

For more options check man grep