Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'System: Host: ict-vm Kernel: 4.4.0-53-generic i686 (32 bit) Desktop: MATE 1.16.1 Distro: Linux Mint 18.1 Serena Machine: System: ASUSTeK (portable) product: N43SN v: 1.0 Mobo: ASUSTeK model: N43SN v: 1.0 serial: NB-1234567890 Bios: American Megatrends v: N43SN.412 date: 09/21/2011 CPU: Quad core Intel Core i7-2670QM (-HT-MCP-) cache: 6144 KB clock speeds: max: 3100 MHz 1: 807 MHz 2: 814 MHz 3: 800 MHz 4: 1078 MHz 5: 990 MHz 6: 811 MHz 7: 801 MHz 8: 844 MHz Graphics: Card-1: Intel 2nd Generation Core Processor Family Integrated Graphics Controller Card-2: NVIDIA GF108M [GeForce GT 550M] Display Server: X.org 1.18.4 drivers: intel (unloaded: fbdev,vesa) FAILED: nouveau tty size: 80x24 Advanced Data: N/A for root Audio: Card Intel 6 Series/C200 Series Family High Definition Audio Controller driver: snd_hda_intel Sound: Advanced Linux Sound Architecture v: k4.4.0-53-generic Network: Card-1: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) driver: ath9k IF: wlp3s0 state: up mac: 7x:2t:61:d4:72:8a Card-2: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet driver: atl1c IF: enp4s0 state: down mac: 14:da:e1:ay:72:b5 Drives: HDD Total Size: 507.9GB (0.4% used) ID-1: /dev/sda model: ST95005620AS size: 500.1GB ID-2: USB /dev/sdb model: DataTraveler_3.0 size: 7.8GB RAID: No RAID devices: /proc/mdstat, md_mod kernel module present Sensors: System Temperatures: cpu: 48.0C mobo: N/A gpu: 43.0 Fan Speeds (in rpm): cpu: N/A Info: Processes: 223 Uptime: 40 min Memory: 531.1/3948.3MB Client: Shell (sudo) inxi: 2.2.35 System: Host: ict-vm Kernel: 4.4.0-53-generic i686 (32 bit) Desktop: MATE 1.16.1 Distro: Linux Mint 18.1 Serena Machine: System: ASUSTeK (portable) product: N43SN v: 1.0 Mobo: ASUSTeK model: N43SN v: 1.0 serial: NB-1234567890 Bios: American Megatrends v: N43SN.412 date: 09/21/2011 CPU: Quad core Intel Core i7-2670QM (-HT-MCP-) cache: 6144 KB clock speeds: max: 3100 MHz 1: 807 MHz 2: 814 MHz 3: 800 MHz 4: 1078 MHz 5: 990 MHz 6: 811 MHz 7: 801 MHz 8: 844 MHz Graphics: Card-1: Intel 2nd Generation Core Processor Family Integrated Graphics Controller Card-2: NVIDIA GF108M [GeForce GT 550M] Display Server: X.org 1.18.4 drivers: intel (unloaded: fbdev,vesa) FAILED: nouveau tty size: 80x24 Advanced Data: N/A for root Audio: Card Intel 6 Series/C200 Series Family High Definition Audio Controller driver: snd_hda_intel Sound: Advanced Linux Sound Architecture v: k4.4.0-53-generic Network: Card-1: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) driver: ath9k IF: wlp3s0 state: up mac: 7x:2t:61:d4:72:8a Card-2: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet driver: atl1c IF: enp4s0 state: down mac: 14:da:e1:ay:72:b5 Drives: HDD Total Size: 507.9GB (0.4% used) ID-1: /dev/sda model: ST95005620AS size: 500.1GB ID-2: USB /dev/sdb model: DataTraveler_3.0 size: 7.8GB RAID: No RAID devices: /proc/mdstat, md_mod kernel module present Sensors: System Temperatures: cpu: 48.0C mobo: N/A gpu: 43.0 Fan Speeds (in rpm): cpu: N/A Info: Processes: 223 Uptime: 40 min Memory: 531.1/3948.3MB Client: Shell (sudo) inxi: 2.2.35'; my $regex = qr/\s*([^:\n]+):\s*((?:(?!: |\n)[\s\S])*)(?=\s+[^:\n]+:|$)/p; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html