sed 命令¶
sed：流编辑器
工作原理：sed 命令会读取当前处理的行，并将它放到“模式空间”进行处理。处理完成后，结果会输出，并且“模式空间”会被清空。接下来读取下一行，并将其放到“模式空间”进行处理，以此类推，直到最后一行。有些文档还会提到一个叫做“保持空间”（也称为“临时存储空间”）的概念，它可以临时存储一些处理过的数据，并通过“模式空间”输出。
“模式空间”和“保持空间”：内存中的一个区域，用于处理和存储数据。
对于未涵盖的信息，请查看sed 手册。
命令的使用方法是
sed [OPTION]... {script-only-if-no-other-script} [input-file]...
| 选项 | 描述 |
|---|---|
| -n | 仅将 sed 命令处理过的文本行输出到屏幕 |
| -e | 将多个 sed 操作命令应用于输入文本行数据 |
| -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 (有时称为操作指令) | 描述 |
|---|---|
| s/regexp/replacement/ | 替换字符串 |
| p | 打印当前“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，并开始下一个循环 |
| = | 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，除了最后一行之外，所有行都需要使用“\”来表示内容尚未结束 |
| i \text | 在匹配行之前添加一行或多行内容。添加多行时，除了最后一行之外，所有行都需要使用“\”来表示内容尚未结束 |
| c \text | 用新文本替换匹配行 |
| q | 立即退出 sed 脚本 |
| r | 附加从文件读取的文本 |
| : label | 用于 b 和 t 命令的标签 |
| b label | 分支到标签；如果省略标签，则分支到脚本末尾 |
| t label | 如果“s///”是成功的替换，则跳转到标签 |
| 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”的方式列出当前行 |
| n N | 将输入的下一行读取/附加到“模式空间” |
| w FILENAME | 将当前模式空间写入 FILENAME |
| ! | 否定 |
| & | 引用已经匹配的字符串 |
| 地址 | 描述 |
|---|---|
| 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 |
| $ | 匹配文本的最后一行 |
| /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 之后的 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提示
众所周知，shell 中的双引号和单引号扮演着不同的角色。双引号中的 $、` 和 \ 具有特殊含义。建议在使用
sed命令时，更多地使用单引号。- 打印第 23 行到第 26 行的文本
Shell > cat -n /etc/services | sed -n '23,26p' 23 tcpmux 1/tcp # TCP port service multiplexer 24 tcpmux 1/udp # TCP port service multiplexer 25 rje 5/tcp # Remote Job Entry 26 rje 5/udp # Remote Job Entry- 打印奇数行
Shell > cat -n /etc/services | sed -n '1~2p' 1 # /etc/services: 3 # 5 # IANA services version: last updated 2016-07-08 7 # Note that it is presently the policy of IANA to assign a single well-known 9 # even if the protocol doesn't support UDP operations. 11 # are included, only the more common ones. 13 # The latest IANA port assignments can be gotten from 15 # The Well Known Ports are those from 0 through 1023. 17 # The Dynamic and/or Private Ports are those from 49152 through 65535 19 # Each line describes one service, and is of the form: ...- 打印第 10 行到最后一行
Shell > cat -n /etc/services | sed -n '10,$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和内容
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- 匹配字符串范围并打印它
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信息
范围的开始：匹配字符串所在的行，只匹配第一个出现的字符串。范围的结束：匹配字符串所在的行，只匹配第一个出现的字符串。
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 行到第 129 行。
- 打印包含字符串所在的行以及之后的行。
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}',$!p' /etc/services # or sed -n "${a},\$!p" /etc/services- 正则表达式
仅匹配 “三位数字” + “/udp”。
Shell > cat /etc/services | sed -r -n '/[^0-9]([1-9]{3}\/udp)/p' sunrpc 111/udp portmapper rpcbind # RPC 4.0 portmapper UDP auth 113/udp authentication tap ident sftp 115/udp uucp-path 117/udp nntp 119/udp readnews untp # USENET News Transfer Protocol ntp 123/udp # Network Time Protocol netbios-ns 137/udp netbios-dgm 138/udp netbios-ssn 139/udp ...匹配并删除 (
d)。它类似于打印，只是操作命令被替换为
d，并且不需要 -n 选项。- 删除所有匹配 udp 字符串的行，删除所有注释行，以及删除所有空行。
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)|(^#)|(^$)/d' http 80/sctp # HyperText Transfer Protocol bgp 179/sctp https 443/sctp # http protocol over TLS/SSL h323hostcall 1720/sctp # H.323 Call Control nfs 2049/sctp nfsd shilp # Network File System rtmp 1/ddp # Routing Table Maintenance Protocol nbp 2/ddp # Name Binding Protocol echo 4/ddp # AppleTalk Echo Protocol zip 6/ddp # Zone Information Protocol discard 9/sctp # Discard discard 9/dccp # Discard SC:DISC ...替换字符串 (
s///g)。语法 语法描述 sed 's/string/replace/g' FILENAMEs: 代表文件内容的所有行。您也可以指定行范围，例如： sed '20,200s/netbios/TMP/g' /etc/services
g (全局)：如果没有 g，则表示当同一行上出现多个匹配的字符串时，只替换第一个匹配的字符串。
/: 分隔符样式。您也可以指定其他样式，例如：sed '20,200s?netbios?TMP?g' /etc/services提示
Bash 脚本中的示例
Shell > vim /root/sedReplace.sh #!/bin/bash a="SELINUX=enforcing" b="SELINUX=disabled" sed -i 's/'${a}'/'${b}'/g' /etc/selinux/config # or sed -i "s/${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/udpShell > 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，并替换指定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- 多个匹配和替换。
Shell > cat /etc/services | sed 's/netbios/test1/g ; s/^#//d ; s/dhcp/&t2/g'- 正则表达式的分组替换。
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，依此类推。
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: 即制表符。
- 将所有注释行替换为空格。
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 \4Shell > 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- 删除任何空白字符。
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。
以下示例
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' # or 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在特定行之上或之下添加内容 (
i和a)。- 在指定行号之上添加两行内容。
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- 在指定行号之下添加三行内容。
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，并在其之上添加 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读取文件内容，并将内容追加到匹配行的下方 (
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将匹配行写入其他文件 (
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将输入的下一行读取/追加到 "模式空间" (
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提示
多个
sed操作命令可能会互相影响，您可以使用 "{ }" 来减少这种影响。- 打印偶数文本行。
首先，读取第一行，因为存在 n 命令；第二行将被打印出来，依此类推。
Shell > cat -n /root/test.txt | sed -n '{n;p}' # or 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- 打印奇数文本行。
Shell > cat -n /root/test.txt | sed -n '{p;n}' # or Shell > cat -n /root/test.txt | sed -n '1~2p' # or 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}' # or 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 SystemN
读取第一行，并在遇到
N命令后追加一行。在本例中，"模式空间" 为 "1\n2"。最后，执行q命令退出。Shell > seq 1 10 | sed 'N;q' 1 2由于第 9 行之后没有额外的行，因此输出如下所示。
Shell > seq 1 9 | sed -n 'N;p' 1 2 3 4 5 6 7 8当读取最后一行时，
N命令不会执行，输出如下所示。Shell > seq 1 9 | sed -n '$!N;p' 1 2 3 4 5 6 7 8 9将两行合并为一行。将 "模式空间" 中的 "\n" 替换为空白字符。
Shell > seq 1 6 | sed 'N;{s/\n//g}' 12 34 56忽略大小写 (
I)。man 1 sed中似乎没有关于忽略大小写的信息。Shell > echo -e "abc\nAbc" | sed -n 's/a/X/Igp' Xbc XBCShell > cat /etc/services | sed '/OEM/Ip' -n oem-agent 3872/tcp # OEM Agent oem-agent 3872/udp # OEM Agent oemcacao-jmxmp 11172/tcp # OEM cacao JMX-remoting access point oemcacao-rmi 11174/tcp # OEM cacao rmi registry access point oemcacao-websvc 11175/tcp # OEM cacao web service access pointShell > cat /etc/services | sed -r '/(TCP)|(UDP)/Id'Shell > cat /etc/services | sed -r '/(TCP)|(UDP)/Ic TMP'获取文件中行的总数。
Shell > cat /etc/services | sed -n '$=' # or Shell > cat /etc/services | wc -l 11473
作者：li tianci