How to fix IP filter regular expressions written using grep command in Linux shell script All In One

How to fix IP filter regular expressions written using grep command in Linux shell script All In One

如何修复在 Linux shell 脚本中使用 grep 命令编写的 IP 过滤器正则表达式？

question ❓

It doesn't work in shell script, but in javascript, it works fine, what's wrong?

I just want to filter out all IPs that are not in the range of 2~254, for example, ignore the 255

error ❌

just want to filter out the 192.168.18.255

#!/usr/bin/env bash

IPs=$(ifconfig | grep -oE '(192\.168\.1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])')
echo $IPs
# 192.168.18.195 192.168.18.255 ❌

IPs1=$(ifconfig | grep -oE '192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])')
echo $IPs1
# 192.168.18.195 192.168.18.25 ❌

IPs2=$(ifconfig | grep -oE '192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])$')
echo $IPs2
# ❌

# wanted, ignore 192.168.18.255 ❓
# IPs=$(ifconfig | grep -oE '❓')
# echo $IPs
# 192.168.18.195

solutions ✅

1. \b

IPs=$(ifconfig | grep -oE '192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])\b')
echo $IPs
# 192.168.18.195

https://unix.stackexchange.com/questions/296596/how-to-check-if-any-ip-address-is-present-in-a-file-using-shell-scripting

2. [[:space:]]

#!/usr/bin/env bash

# [[:space:]] ✅
IPs2=$(ifconfig | grep -oE '192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])[[:space:]]')
echo "$IPs2 🚀"
# ✅

test environment	result
macOS 13.1	✅
Raspberry Pi OS x64	✅

input IPs

$ ifconfig

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
        inet 127.0.0.1 netmask 0xff000000 
        inet6 ::1 prefixlen 128 
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
        nd6 options=201<PERFORMNUD,DAD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=50b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV,CHANNEL_IO>
        ether f0:18:98:f3:0d:de 
        nd6 options=201<PERFORMNUD,DAD>
        media: autoselect (none)
        status: inactive
en6: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        ether ac:de:48:00:11:22 
        inet6 fe80::aede:48ff:fe00:1122%en6 prefixlen 64 scopeid 0x5 
        nd6 options=201<PERFORMNUD,DAD>
        media: autoselect (100baseTX <full-duplex>)
        status: active
ap1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
        options=400<CHANNEL_IO>
        ether a6:83:e7:91:62:79 
        media: autoselect
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=6463<RXCSUM,TXCSUM,TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
        ether a4:83:e7:91:62:79 
        inet6 fe80::1ca2:3b0a:df9d:465f%en1 prefixlen 64 secured scopeid 0x7 
        inet 192.168.18.195 netmask 0xffffff00 broadcast 192.168.18.255
        inet6 fd80:eae6:1258:0:37:7544:1d1:7b08 prefixlen 64 autoconf secured 
        nd6 options=201<PERFORMNUD,DAD>
        media: autoselect
        status: active
en4: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=460<TSO4,TSO6,CHANNEL_IO>
        ether 82:c5:92:66:c0:05 
        media: autoselect <full-duplex>
        status: inactive
en5: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=460<TSO4,TSO6,CHANNEL_IO>
        ether 82:c5:92:66:c0:04 
        media: autoselect <full-duplex>
        status: inactive
en3: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=460<TSO4,TSO6,CHANNEL_IO>
        ether 82:c5:92:66:c0:00 
        media: autoselect <full-duplex>
        status: inactive
en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=460<TSO4,TSO6,CHANNEL_IO>
        ether 82:c5:92:66:c0:01 
        media: autoselect <full-duplex>
        status: inactive
awdl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=6463<RXCSUM,TXCSUM,TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
        ether b2:1c:61:d6:e4:c3 
        inet6 fe80::b01c:61ff:fed6:e4c3%awdl0 prefixlen 64 scopeid 0xc 
        nd6 options=201<PERFORMNUD,DAD>
        media: autoselect
        status: active
bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=63<RXCSUM,TXCSUM,TSO4,TSO6>
        ether 82:c5:92:66:c0:01 
        Configuration:
                id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
                maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
                root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
                ipfilter disabled flags 0x0
        member: en2 flags=3<LEARNING,DISCOVER>
                ifmaxaddr 0 port 11 priority 0 path cost 0
        member: en3 flags=3<LEARNING,DISCOVER>
                ifmaxaddr 0 port 10 priority 0 path cost 0
        member: en4 flags=3<LEARNING,DISCOVER>
                ifmaxaddr 0 port 8 priority 0 path cost 0
        member: en5 flags=3<LEARNING,DISCOVER>
                ifmaxaddr 0 port 9 priority 0 path cost 0
        nd6 options=201<PERFORMNUD,DAD>
        media: <unknown type>
        status: inactive
llw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=400<CHANNEL_IO>
        ether b2:1c:61:d6:e4:c3 
        inet6 fe80::b01c:61ff:fed6:e4c3%llw0 prefixlen 64 scopeid 0xe 
        nd6 options=201<PERFORMNUD,DAD>
        media: autoselect
        status: inactive
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
        inet6 fe80::cd36:3613:d45c:3ef5%utun0 prefixlen 64 scopeid 0xf 
        nd6 options=201<PERFORMNUD,DAD>
utun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
        inet6 fe80::b421:12b2:245a:cced%utun1 prefixlen 64 scopeid 0x10 
        nd6 options=201<PERFORMNUD,DAD>
utun2: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1000
        inet6 fe80::ce81:b1c:bd2c:69e%utun2 prefixlen 64 scopeid 0x11 
        nd6 options=201<PERFORMNUD,DAD>
utun3: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
        inet6 fe80::9e8d:e6dc:c364:f6df%utun3 prefixlen 64 scopeid 0x12 
        nd6 options=201<PERFORMNUD,DAD>
utun4: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
        inet6 fe80::facb:f21b:e5cf:ef54%utun4 prefixlen 64 scopeid 0x13 
        nd6 options=201<PERFORMNUD,DAD>
utun5: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
        inet6 fe80::9b81:5e7e:afff:8f8b%utun5 prefixlen 64 scopeid 0x14 
        nd6 options=201<PERFORMNUD,DAD>
utun6: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1380
        inet6 fe80::b3a5:3e87:f36d:c096%utun6 prefixlen 64 scopeid 0x15 
        nd6 options=201<PERFORMNUD,DAD>

RegExp tools

1. regexper

/192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])$/

/192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])[[:space:]]/

192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])[[:space:]]

https://regexper.com/

2. regex101

https://regex101.com/

https://regex101.com/r/LY2pjB/1

demos

$ ./regex-space.sh

$ cat ./regex-space.sh

#!/usr/bin/env bash

IPs=$(ifconfig | grep -oE '192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])\b')

# echo $IPs
# 192.168.18.195

# Print the IP address
if [ "$IPs" ]; then
  printf "My IP address is %s\n" "$IPs"
  printf "🌲🍓我的IP地址是 %s\n" "$IPs"
fi

exit 0

$ cat ./ip.sh

#!/usr/bin/env bash

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
  printf "🌲🍓我的IP地址是 %s\n" "$_IP"
fi

exit 0

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javascript

function test(n) {
  let reg = /192\.168\.(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.([2-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-4])$/;
   for (let i = 0; i < n; i++) {
     let result = reg.test(`192.168.18.${i}`);
     if(result) {
       // console.log(`192.168.18.${i} ✅`, i, result)
     } else {
       console.log(`192.168.18.${i} ❌`, i, result)
     }
   }
}

test(256);

192.168.18.0 ❌ 0 false
192.168.18.1 ❌ 1 false
192.168.18.255 ❌ 255 false

GNU Linux

$ uname -a
Darwin xgqfrms-mm.local 22.2.0 Darwin Kernel Version 22.2.0: Fri Nov 11 02:08:47 PST 2022; root:xnu-8792.61.2~4/RELEASE_X86_64 x86_64

$  uname -a
Linux raspberrypi 5.15.84-v8+ #1613 SMP PREEMPT Thu Jan 5 12:03:08 GMT 2023 aarch64 GNU/Linux

https://raspberrytips.com/which-raspberry-pi-os-is-running/

# Raspberry Pi OS
pi@raspberrypi:~/Desktop $ cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"


pi@raspberrypi:~/Desktop $ hostnamectl
   Static hostname: raspberrypi
         Icon name: computer
        Machine ID: 8c3a6ca2b3734bd09010fb558b96f301
           Boot ID: 4ef4f2fd0b3e4faea6c58e365471040a
  Operating System: Debian GNU/Linux 11 (bullseye)
            Kernel: Linux 5.15.84-v8+
      Architecture: arm64
pi@raspberrypi:~/Desktop $ 

bullseye 靶心

How to see Raspberry Pi OS version on Raspberry PI

https://www.cyberciti.biz/faq/linux-command-print-raspberry-pi-os-version-on-raspberry-pi/

refs

[[:space:]] 空格 / Whitespace

https://www.cnblogs.com/xgqfrms/p/17358543.html

https://stackoverflow.com/questions/76108452/how-to-fix-ip-filter-regular-expressions-written-using-grep-command-in-linux-she

https://www.cnblogs.com/xgqfrms/p/17351421.html#5171976

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