sed系列:行或者模式匹配删除特定行

“p” command prints the buffer (remember to use -n option with “p”)
“d” command is just opposite, its for deletion. ‘d’ will delete the pattern space buffer and immediately starts the next cycle.

Syntax:
# sed 'ADDRESS'd filename
# sed /PATTERN/d filename

Let us first creates thegeekstuff.txt file that will be used in all the examples mentioned below.
# cat thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
10.Windows- Sysadmin, reboot etc.

例子１:删除第ｎ行
sed ‘Nd’ filename
As per sed methodology,
It reads the first line and places in its pattern buffer.
Check whether supplied command is true for this line, if true, deletes pattern space buffer and starts next cycle. i.e Read next line.
If supplied command doesnt true, as its normal behaviour it prints the content of the pattern space buffer.

$ sed 3d thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
10.Windows- Sysadmin, reboot etc.

例２:从第三行开始,每隔一行删除
$sed 3~2d thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
4. Security (Firewall, Network, Online Security etc)
6. Cool gadgets and websites
8. Website Design
10.Windows- Sysadmin, reboot etc.

例３:删除从第４行到第８行
$sed 4,8d thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
9. Software Development
10.Windows- Sysadmin, reboot etc.
$sed '4,8d' thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
9. Software Development
10.Windows- Sysadmin, reboot etc.
$sed '4,8'd thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
9. Software Development
10.Windows- Sysadmin, reboot etc.

例４:删除最后一行
$sed '$'d thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
$sed '$d' thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development

例５:行匹配删除
$sed /Sysadmin/d thegeekstuff.txt
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
$sed '/Sysadmin/d' thegeekstuff.txt
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
$sed '/Sysadmin/'d thegeekstuff.txt
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development

例６:从匹配行到末尾行
$sed '/Website Design/,$d' thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
$sed '/Website Design/,$'d thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)

例７:删除匹配行和之后两行
$sed '/Storage/,+2d' thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
8. Website Design
9. Software Development
10.Windows- Sysadmin, reboot etc.
$sed '/Storage/,+2'd thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
8. Website Design
9. Software Development
10.Windows- Sysadmin, reboot etc.

例８:删除空行
$sed '/^$/d' thegeekstuff.txt
1. Linux - Sysadmin, Scripting etc.
2. Databases - Oracle, mySQL etc.
3. Hardware
4. Security (Firewall, Network, Online Security etc)
5. Storage
6. Cool gadgets and websites
7. Productivity (Too many technologies to explore, not much time available)
8. Website Design
9. Software Development
10.Windows- Sysadmin, reboot etc.