`sed` 命令¶

sed：流编辑器

工作原理：sed 命令将读取当前处理的行，并将其放置在 "模式空间（pattern space）" 中进行处理。处理完成后，将输出结果并清除 "模式空间"。接着读取下一行并放入 "模式空间" 继续处理，依此类推，直到最后一行。某些文档中还提到了一个称为 "保持空间（hold spcae）"（也称 "临时存储空间（temporary-storage space）"）的术语，它可以暂时存储部分已处理的数据，并通过 "模式空间" 输出。

"模式空间" 和 "保持空间"：处理和存储数据的内存区域。

有关未涵盖的信息，请参阅 sed 手册页。

该命令的用法是：

sed [OPTION]... {script-only-if-no-other-script} [input-file]...

选项	说明
-n	将仅由 `sed` 命令处理的文本行输出到屏幕上
-e	对输入文本行数据应用多个 `sed` 操作命令
-f	调用并执行 `sed` 脚本命令文件
-i	修改原始文件
-r	正则表达式

操作命令（有时也称操作指令）	说明
s/regexp/replacement/	替换字符串
p	打印当前的 "模式空间"。通常与 -n 选项一起使用，例如：`cat -n /etc/services \\| sed -n '3,5p'`
d	删除 "模式空间"。开始下一个循环
D	删除 "模式空间" 的第一行，开始下一个循环
=	打印行号
a \text	在匹配行之后添加一行或多行内容。添加多行时，除最后一行外的所有行都需要使用 "\" 表示内容尚未结束
i \text	在匹配行之前添加一行或多行内容。添加多行时，除最后一行外的所有行都需要使用 "\" 表示内容尚未结束
c \text	用新文本替换匹配行
q	立即退出 `sed` 脚本
r	追加从文件读取的文本
: label	b 和 t 命令的标签
b label	跳转到标签；如果未指定标签，则跳转到脚本结尾
t label	如果 "s///" 是成功的替换，则跳到标签
h H	将 "模式空间" 复制/追加到 "保持空间"
g G	将 "保持空间" 复制/追加到 "模式空间"
x	交换保持空间和模式空间的内容
l	以 "视觉上明确无误" 的形式列出当前行
n N	将输入的下一行读入/追加到 "模式空间" 中
w FILENAME	将当前 "模式空间" 写入到 FILENAME
!	取反
&	引用已匹配的字符串

地址	说明
first~step	使用 "first" 指定第一行，使用 "step" 指定步长。例如，使用 `sed -n "1~2p" /etc/services` 输出文本的奇数行
$	匹配最后一行文本
/regexp/	使用正则表达式匹配文本行
number	指定行号
addr1,addr2	使用行号定位来匹配从 "addr1" 到 "addr2" 的所有行
addr1,+N	使用行号定位来匹配 "addr1" 和 "addr1" 后面的 N 行

使用示例¶

匹配并打印（p）

打印以 netbios 字符串开头的行

Shell > cat /etc/services | sed -n '/^netbios/p'
netbios-ns      137/tcp                         # NETBIOS Name Service
netbios-ns      137/udp
netbios-dgm     138/tcp                         # NETBIOS Datagram Service
netbios-dgm     138/udp
netbios-ssn     139/tcp                         # NETBIOS session service
netbios-ssn     139/udp

!!! tip "提示"

  众所周知，shell 中的双引号和单引号起着不同的作用。双引号中的 **$**、**\`** 和 **\\** 具有特殊含义。建议在使用 `sed` 命令时更频繁地使用单引号。

打印第 23 行至第 26 行的文本

Shell > cat -n /etc/services | sed -n '23,26p'
23  tcpmux          1/tcp                           # TCP port service multiplexer
24  tcpmux          1/udp                           # TCP port service multiplexer
25  rje             5/tcp                           # Remote Job Entry
26  rje             5/udp                           # Remote Job Entry

打印奇数行

Shell > cat -n /etc/services | sed -n '1~2p'
1  # /etc/services:
3  #
5  # IANA services version: last updated 2016-07-08
7  # Note that it is presently the policy of IANA to assign a single well-known
9  # even if the protocol doesn't support UDP operations.
11  # are included, only the more common ones.
13  # The latest IANA port assignments can be gotten from
15  # The Well Known Ports are those from 0 through 1023.
17  # The Dynamic and/or Private Ports are those from 49152 through 65535
19  # Each line describes one service, and is of the form:
...

打印第 10 行到最后一行

Shell > cat -n /etc/services | sed -n '10,$p'
10  # Updated from RFC 1700, ``Assigned Numbers'' (October 1994).  Not all ports
11  # are included, only the more common ones.
12  #
13  # The latest IANA port assignments can be gotten from
14  #       http://www.iana.org/assignments/port-numbers
15  # The Well Known Ports are those from 0 through 1023.
16  # The Registered Ports are those from 1024 through 49151
17  # The Dynamic and/or Private Ports are those from 49152 through 65535
...

第 10 行到最后一行不打印

Shell > cat -n /etc/services | sed -n '10,$!p'
1  # /etc/services:
2  # $Id: services,v 1.49 2017/08/18 12:43:23 ovasik Exp $
3  #
4  # Network services, Internet style
5  # IANA services version: last updated 2016-07-08
6  #
7  # Note that it is presently the policy of IANA to assign a single well-known
8  # port number for both TCP and UDP; hence, most entries here have two entries
9  # even if the protocol doesn't support UDP operations.

打印匹配字符串的行号及其内容

Shell > sed -n -e '/netbios/=' -e '/netbios/p' /etc/services
123
netbios-ns      137/tcp                         # NETBIOS Name Service
124
netbios-ns      137/udp
125
netbios-dgm     138/tcp                         # NETBIOS Datagram Service
126
netbios-dgm     138/udp
127
netbios-ssn     139/tcp                         # NETBIOS session service
128
netbios-ssn     139/udp

匹配字符串范围并将其打印出来

使用逗号分隔字符串范围

Shell > cat  /etc/services | sed -n '/^netbios/,/^imap/p'
netbios-ns      137/tcp                         # NETBIOS Name Service
netbios-ns      137/udp
netbios-dgm     138/tcp                         # NETBIOS Datagram Service
netbios-dgm     138/udp
netbios-ssn     139/tcp                         # NETBIOS session service
netbios-ssn     139/udp
imap            143/tcp         imap2           # Interim Mail Access Proto v2

!!! info "信息"

  **范围起始**：匹配字符串所在的行，仅匹配出现的第一个字符串。
  **范围结束**：匹配字符串所在的行，仅匹配出现的第一个字符串。

Shell > grep -n ^netbios /etc/services
123:netbios-ns      137/tcp                         # NETBIOS Name Service
124:netbios-ns      137/udp
125:netbios-dgm     138/tcp                         # NETBIOS Datagram Service
126:netbios-dgm     138/udp
127:netbios-ssn     139/tcp                         # NETBIOS session service
128:netbios-ssn     139/udp

Shell > grep -n ^imap /etc/services
129:imap            143/tcp         imap2           # Interim Mail Access Proto v2
130:imap            143/udp         imap2
168:imap3           220/tcp                         # Interactive Mail Access
169:imap3           220/udp                         # Protocol v3
260:imaps           993/tcp                         # IMAP over SSL
261:imaps           993/udp                         # IMAP over SSL

换句话说，上面打印的内容是第 123 至 129 行

打印字符串所在的行，直到最后一行

Shell > cat /etc/services | sed -n '/^netbios/,$p'

在 bash 脚本中使用变量

Shell > vim test1.sh
#!/bin/bash
a=10

sed -n ''${a}',$!p' /etc/services
# 或者
sed -n "${a},\$!p" /etc/services

正则表达式

仅匹配 "三位数" + "/udp"。

Shell > cat /etc/services  | sed -r -n '/\s([1-9][0-9]{2}\/udp)/p' | sort -k 2
hostname        101/udp         hostnames       # usually from sri-nic
iso-tsap        102/udp                 # ISO-TSAP Class 0
gppitnp         103/udp                 # Genesis Point-to-Point Trans Net
acr-nema        104/udp                 # ACR-NEMA Digital Imag. & Comm. 300
csnet-ns        105/udp         cso
poppassd        106/udp                         # Eudora
#3com-tsmux     106/udp         poppassd
rtelnet         107/udp
snagas          108/udp                 # SNA Gateway Access Server
...

匹配并删除（d）

它类似于打印，只是操作命令被替换为 d 且不需要 -n 选项。

删除与 udp 字符串匹配的所有行，删除所有注释行，并删除所有空白行

Shell > sed -e '/udp/d' -e '/^#/d' -e '/^$/d' /etc/services
tcpmux          1/tcp                           # TCP port service multiplexer
rje             5/tcp                           # Remote Job Entry
echo            7/tcp
discard         9/tcp           sink null
systat          11/tcp          users
daytime         13/tcp
qotd            17/tcp          quote
chargen         19/tcp          ttytst source
ftp-data        20/tcp
ftp             21/tcp
ssh             22/tcp                          # The Secure Shell (SSH) Protocol
telnet          23/tcp
...

删除连续的文本行

Shell > cat -n /etc/services | sed '10,$d'
1  # /etc/services:
2  # $Id: services,v 1.49 2017/08/18 12:43:23 ovasik Exp $
3  #
4  # Network services, Internet style
5  # IANA services version: last updated 2016-07-08
6  #
7  # Note that it is presently the policy of IANA to assign a single well-known
8  # port number for both TCP and UDP; hence, most entries here have two entries
9  # even if the protocol doesn't support UDP operations.

正则表达式

Shell > cat  /etc/services | sed -r '/(tcp)|(udp)|(^#)|(^$)/d'
http            80/sctp                         # HyperText Transfer Protocol
bgp             179/sctp
https           443/sctp                        # http protocol over TLS/SSL
h323hostcall    1720/sctp                       # H.323 Call Control
nfs             2049/sctp       nfsd shilp      # Network File System
rtmp            1/ddp                           # Routing Table Maintenance Protocol
nbp             2/ddp                           # Name Binding Protocol
echo            4/ddp                           # AppleTalk Echo Protocol
zip             6/ddp                           # Zone Information Protocol
discard         9/sctp                  # Discard
discard         9/dccp                  # Discard SC:DISC
...

替换字符串（s///g）

语法	语法说明
`sed 's/string/replace/g' FILENAME`	s：表示文件内容的所有行。您还可以指定行的范围，例如：`sed '20,200s/netbios/TMP/g' /etc/services`。 g（Global）：如果没有 g，这意味着当单行上出现多个匹配字符串时，只会替换第一个匹配字符串。 /：分隔符样式。您还可以指定其他样式，例如：`sed '20,200s?netbios?TMP?g' /etc/services`

您还可以在 bash 脚本中使用替换功能。

例如：

Shell > vim /root/sedReplace.sh
#!/bin/bash
a="SELINUX=enforcing"
b="SELINUX=disabled"

sed -i 's/'${a}'/'${b}'/g' /etc/selinux/config
# 或者
sed -i "s/${a}/${b}/g" /etc/selinux/config

替换并打印

Shell > sed -n '44,45s/ssh/SSH/gp' /etc/services
SSH             22/tcp
SSH             22/udp

使用 "&" 符号引用字符串

Shell > sed -n '44,45s/ssh/&-SSH/gp' /etc/services
ssh-SSH             22/tcp
ssh-SSH             22/udp

使用字符串定位一行或多行，并替换行范围内的指定字符串

Shell > grep ssh /etc/services -n
44:ssh             22/tcp                          # The Secure Shell (SSH) Protocol
45:ssh             22/udp                          # The Secure Shell (SSH) Protocol
551:x11-ssh-offset  6010/tcp                        # SSH X11 forwarding offset
593:ssh             22/sctp                 # SSH
1351:sshell          614/tcp                 # SSLshell
1352:sshell          614/udp                 #       SSLshell
1607:netconf-ssh     830/tcp                 # NETCONF over SSH
1608:netconf-ssh     830/udp                 # NETCONF over SSH
7178:sdo-ssh         3897/tcp                # Simple Distributed Objects over SSH
7179:sdo-ssh         3897/udp                # Simple Distributed Objects over SSH
7791:netconf-ch-ssh  4334/tcp                # NETCONF Call Home (SSH)
8473:snmpssh         5161/tcp                # SNMP over SSH Transport Model
8474:snmpssh-trap    5162/tcp                # SNMP Notification over SSH Transport Model
9126:tl1-ssh         6252/tcp                # TL1 over SSH
9127:tl1-ssh         6252/udp                # TL1 over SSH
10796:ssh-mgmt        17235/tcp               # SSH Tectia Manager
10797:ssh-mgmt        17235/udp               # SSH Tectia Manager

Shell > sed '/ssh/s/tcp/TCP/gp' -n  /etc/services
ssh             22/TCP                          # The Secure Shell (SSH) Protocol
x11-ssh-offset  6010/TCP                        # SSH X11 forwarding offset
sshell          614/TCP                 # SSLshell
netconf-ssh     830/TCP                 # NETCONF over SSH
sdo-ssh         3897/TCP                # Simple Distributed Objects over SSH
netconf-ch-ssh  4334/TCP                # NETCONF Call Home (SSH)
snmpssh         5161/TCP                # SNMP over SSH Transport Model
snmpssh-trap    5162/TCP                # SNMP Notification over SSH Transport Model
tl1-ssh         6252/TCP                # TL1 over SSH
ssh-mgmt        17235/TCP               # SSH Tectia Manager

连续行的字符串替换

Shell > sed '10,30s/tcp/TCP/g' /etc/services

多次匹配和替换

Shell > cat /etc/services | sed 's/netbios/test1/g ; s/^#//g ; s/dhcp/&t2/g'

正则表达式的组替换

在正则表达式中，"()" 是一个分组。 \1 代表引用组1，\2 代表引用组2，以此类推。

Shell > cat /etc/services
...
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

Shell > cat /etc/services | sed -r 's/([0-9]*\/tcp)/\1\tCONTENT1/g ; s/([0-9]*\/udp)/\1\tADD2/g'
...
axio-disc       35100/tcp       CONTENT1               # Axiomatic discovery protocol
axio-disc       35100/udp       ADD2               # Axiomatic discovery protocol
pmwebapi        44323/tcp       CONTENT1               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp       ADD2               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp       CONTENT1               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp       CONTENT1               # Capture handwritten signatures

\t：即一个制表符

将所有注释行替换为空白行

Shell > cat /etc/services | sed -r 's/(^#.*)//g'
...
chargen         19/udp          ttytst source
ftp-data        20/tcp
ftp-data        20/udp

ftp             21/tcp
ftp             21/udp          fsp fspd
ssh             22/tcp                          # The Secure Shell (SSH) Protocol
ssh             22/udp                          # The Secure Shell (SSH) Protocol
...

将单词中的一个小写字母替换为大写字母

Shell > echo -e "hello,world\nPOSIX" | sed -r 's/(.*)w/\1W/g'
hello,World
POSIX

字符串位置交换

Shell > cat /etc/services
...
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

我们可以将此文件分为五个部分：

cloudcheck-ping    45514       /     udp        # ASSIA CloudCheck WiFi Management keepalive
 ↓                   ↓         ↓      ↓               ↓
(.*)           (\<[0-9]+\>)   \/   (tcp|udp)         (.*)
 ↓                   ↓                ↓               ↓ 
 \1                 \2               \3              \4

Shell > cat /etc/services | sed -r 's/(.*)(\<[0-9]+\>)\/(tcp|udp)(.*)/\1\3\/\2\4/g'
...
edi_service     udp/34567               # dhanalakshmi.org EDI Service
axio-disc       tcp/35100               # Axiomatic discovery protocol
axio-disc       udp/35100               # Axiomatic discovery protocol
pmwebapi        tcp/44323               # Performance Co-Pilot client HTTP API
cloudcheck-ping udp/45514               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      tcp/45514               # ASSIA CloudCheck WiFi Management System
spremotetablet  tcp/46998               # Capture handwritten signatures

删除所有空白字符

Shell > echo -e "abcd\t1 2 3 4\tWorld"
abcd    1 2 3 4 World
Shell > echo -e "abcd\t1 2 3 4\tWorld" | sed -r 's/(\s)*//g'
abcd1234World

使用 -e 选项执行多次

示例如下：

Shell > tail -n 10 /etc/services
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

Shell > tail -n 10 /etc/services | sed  -e '1,3d' -e '/cloud/s/ping/PING/g'
# 或者
Shell > tail -n 10 /etc/services | sed  '1,3d ; /cloud/s/ping/PING/g'
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-PING 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

在特定行上方或下方添加内容（i 和 a）

在指定行号上方添加两行内容

Shell > tail -n 10 /etc/services > /root/test.txt
Shell > cat /root/test.txt
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

Shell > cat /root/test.txt | sed '3i 123\
abc'
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
123
abc
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

在指定行号下方添加三行

Shell > cat /root/test.txt | sed '5a 123\
comment yes\
tcp or udp'
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
123
comment yes
tcp or udp
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

根据字符串匹配特定行，并在其上方添加 2 行内容

Shell > cat /root/test.txt | sed '/tcp/iTCP\
UDP'
TCP
UDP
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
TCP
UDP
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
TCP
UDP
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
TCP
UDP
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
TCP
UDP
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
TCP
UDP
spremotetablet  46998/tcp               # Capture handwritten signatures

替换行（c）

根据字符串定位一行或多行，并替换这些文本行

Shell > cat /root/test.txt | sed '/ser/c\TMP1 \
TMP2'
TMP1
TMP2
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
TMP1
TMP2
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

单行替换

Shell > cat /root/test.txt | sed '7c REPLACE'
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
REPLACE
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

替换连续的文本行

Shell > cat /root/test.txt | sed '2,$c REPLACE1 \
replace2'
aigairserver    21221/tcp               # Services for Air Server
REPLACE1
replace2

替换偶数行

Shell > cat /root/test.txt | sed '2~2c replace'
aigairserver    21221/tcp               # Services for Air Server
replace
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
replace
axio-disc       35100/tcp               # Axiomatic discovery protocol
replace
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
replace
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
replace

读取文件的内容，并将其内容追加到匹配行下方（r）

Shell > cat /root/app.txt
append1
POSIX
UNIX

Shell > cat /root/test.txt | sed '/ping/r /root/app.txt'
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
append1
POSIX
UNIX
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

将匹配的行写入到其他文件（w）

Shell > cat /root/test.txt | sed '/axio/w /root/storage.txt'

Shell > cat /root/storage.txt
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol

将下一行输入读取/追加到 "模式空间" 中（n 和 N）

打印匹配行的下一行

Shell > cat /root/test.txt
aigairserver    21221/tcp               # Services for Air Server
ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
edi_service     34567/udp               # dhanalakshmi.org EDI Service
axio-disc       35100/tcp               # Axiomatic discovery protocol
axio-disc       35100/udp               # Axiomatic discovery protocol
pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System
spremotetablet  46998/tcp               # Capture handwritten signatures

Shell > cat /root/test.txt | sed '/ping/{n;p}' -n
cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System

!!! tip "提示"

  多个 `sed` 操作命令可能会相互影响，您可以使用 "**{ }**" 来减少这种影响。

打印偶数行文本

首先，读取首行。因为使用了 n 命令，所以将打印第二行，依此类推。

Shell > cat -n /root/test.txt | sed -n '{n;p}'
# 或者
Shell > cat -n /root/test.txt | sed -n '2~2p'
2  ka-kdp          31016/udp               # Kollective Agent Kollective Delivery
4  edi_service     34567/udp               # dhanalakshmi.org EDI Service
6  axio-disc       35100/udp               # Axiomatic discovery protocol
8  cloudcheck-ping 45514/udp               # ASSIA CloudCheck WiFi Management keepalive
10  spremotetablet  46998/tcp               # Capture handwritten signatures

打印奇数行文本

Shell > cat -n /root/test.txt | sed -n '{p;n}'
# 或
Shell > cat -n /root/test.txt | sed -n '1~2p'
# 或
Shell > cat -n /root/test.txt | sed 'n;d'
1  aigairserver    21221/tcp               # Services for Air Server
3  ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
5  axio-disc       35100/tcp               # Axiomatic discovery protocol
7  pmwebapi        44323/tcp               # Performance Co-Pilot client HTTP API
9  cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System

打印 3n 行

Shell > cat -n /root/test.txt | sed -n '{n;n;p}'
# 或
Shell > cat -n /root/test.txt | sed -n '3~3p'
3  ka-sddp         31016/tcp               # Kollective Agent Secure Distributed Delivery
6  axio-disc       35100/udp               # Axiomatic discovery protocol
9  cloudcheck      45514/tcp               # ASSIA CloudCheck WiFi Management System

N

读取第一行，并在遇到 "N" 命令后追加一行。在这个例子中，"模式空间" 是 "1\n2"。最后，执行 q 命令退出。
```
Shell > seq 1 10 | sed 'N;q'
1
2
```
因为第 9 行之后没有额外的行，所以输出如下：
```
Shell > seq 1 9 | sed -n 'N;p'
1
2
3
4
5
6
7
8
```
当读取最后一行时，不执行 N 命令，输出如下：
```
Shell > seq 1 9 | sed -n '$!N;p'
1
2
3
4
5
6
7
8
9
```
将两行合并为一行。将 "模式空间" 中的 "\n" 替换为空白字符。
```
Shell > seq 1 6 | sed 'N;{s/\n//g}'
12
34
56
```

忽略大小写（I）

在 man 1 sed 中似乎没有关于忽略大小写的信息。

Shell > echo -e "abc\nAbc" | sed -n 's/a/X/Igp'
Xbc
XBC

Shell > cat /etc/services | sed '/OEM/Ip' -n
oem-agent       3872/tcp                # OEM Agent
oem-agent       3872/udp                # OEM Agent
oemcacao-jmxmp  11172/tcp               # OEM cacao JMX-remoting access point
oemcacao-rmi    11174/tcp               # OEM cacao rmi registry access point
oemcacao-websvc 11175/tcp               # OEM cacao web service access point

Shell > cat /etc/services | sed -r '/(TCP)|(UDP)/Id'

Shell > cat /etc/services | sed -r '/(TCP)|(UDP)/Ic TMP'

获取文件中的总行数

Shell > cat /etc/services | sed -n '$='
# 或者
Shell > cat /etc/services | wc -l

11473

Author: tianci li

sed 命令¶

使用示例¶

`sed` 命令¶