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

用了三年多了DigitalOcean,最近发现Vultr的性价比更高,速度更快。

还犹豫什么?换!

目前感觉速度还不错~ 有海外虚拟机需求的朋友可以关注了。

还在用ISP给的DNS?有没发现一些网站上不去了?

试试下面几个公共DNS服务器:

  1. DNSPod
    首选:119.29.29.29
    备选:182.254.116.116
  2. 114DNS
    首选:114.114.114.114
    备选:114.114.114.115
  3. 阿里DNS首选:223.5.5.5
    备选:223.6.6.6
  4. DNS派
    首选(电信/移动/铁通):101.226.4.6
    备选(电信/移动/铁通):218.30.118.6

    首选(联通):123.125.81.6
    备选(联通):140.207.198.6

  5. 百度DNS
    首选:180.76.76.76

如果碰上一些MP4中的音乐特别好听的,想转成MP3的话怎么办?

用ffmpeg就可以实现:

ffmpeg -i a.mp4 b.mp3

还可以加 -b:a 192k 来指定码率

更多参数可参照:https://trac.ffmpeg.org/wiki/Encode/MP3