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

/
/
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'CHOC_METRICS_2020-06-16.csv Claims_PGSEO_20200110.txt Claims_Agilon_20200110.txt COPC_PE20190701_REHCF.TXT Member_Agilon_PGSEO_Current_QualityRA_History_20200116.txt Member_Agilon_PGSEO_Current_QualityRA_20200215.txt Member_Agilon_PGSEO_Locked_Financial_20200115.txt Member_Agilon_PGSEO_Locked_Financial_History_20200116.txt Claims_PGSEO_History_20200116.txt Member_Agilon_Current_QualityRA_20200215.txt Member_Agilon_Locked_Financial_20191215.txt COPC_ME_AETACOE6_201912_20200127.txt SGPPN_PE20190701_REHCF.TXT SGPPN_PE20200101_RECLMEXP.TXT SGAGAKRN_PE20200301_RECLMEXP.TXT PCMS_Inpatient_Admission_Patients_20190802100552.csv PCMS_Inpatient_Admission_Patients_20190821154559.csv Humana Dayton Census - Authorizations 4.30.20 Authorizations.csv Humana Dayton Census - Authorizations 5.11.20.csv Humana Dayton Census - Authorizations 4.30.20 Admits Discharges.csv 2020_05_04_Census.txt 2020_05_03_Discharges_Rolling7Days.txt 2020_05_04_Census.txt 2020_05_04_Discharges_Rolling7Days.txt 2019_12_21_Discharges_Rolling7Days.txt 2019_12_21_Census.txt CHOC_RT_OutreachAttempt_20200502.csv CHOC_RT_OutreachAttempt_20200509.csv SGPPN_PE20200101_REMBX.TXT PriMed_Phy_MAPPO_claim_det_02132020.txt PriMed_Phy_MAPPO_claim_header_02132020.txt PriMed_Phy_MAPPO_claim_header_proc_02132020.txt PriMed_Phy_MAPPO_CLM_DIAG_02132020.txt PriMed_Phy_MAPPO_member_02132020.txt PriMed_Phy_MAPPO_member_eligibility_02132020.txt OHCore_Care_Select_member_eligibility_01232020.txt OHCore_Care_Select_member_eligibility_04152019.txt OHCore_Care_Select_claim_det_07152019.txt OHCore_Care_Select_claim_det_06182018.txt OHCore_Care_Select_claim_det_01232020.txt Pioneer_Phy_MAPPO_claim_det_02132020.txt Pioneer_Phy_MAPPO_claim_header_02132020.txt Pioneer_Phy_MAPPO_claim_header_proc_02132020.txt Pioneer_Phy_MAPPO_CLM_DIAG_02132020.txt Pioneer_Phy_MAPPO_member_02132020.txt Pioneer_Phy_MAPPO_member_eligibility_02132020.txt Physicians_Grp_Sohio_MAPPO_claim_det_02132020.txt Physicians_Grp_Sohio_MAPPO_claim_header_02132020.txt Physicians_Grp_Sohio_MAPPO_claim_header_proc_02132020.txt Physicians_Grp_Sohio_MAPPO_CLM_DIAG_02132020.txt Physicians_Grp_Sohio_MAPPO_member_02132020.txt Physicians_Grp_Sohio_MAPPO_member_eligibility_02132020.txt Central_Ohio_PC_MAPPO_claim_det_02132020.txt Central_Ohio_PC_MAPPO_claim_header_02132020.txt Central_Ohio_PC_MAPPO_CLM_DIAG_02132020.txt Central_Ohio_PC_MAPPO_member_02132020.txt Central_Ohio_PC_MAPPO_member_eligibility_02132020.txt Central_Ohio_PC_MAPPO_claim_header_proc_02132020.txt CORECARESELECT1OH_ENC_837P_20190927_529128 Copy of Pioneer_DailyAuth_SummaCare_20191227.csv Copy of Pioneer_DailyAuth_SummaCare_20200329.csv Copy of Pioneer_DailyAuth_SummaCare_20200414.csv Copy of Pioneer_DailyAuth_SummaCare_20200402.csv Pioneer_DailyAuth_SummaCare_20191227.csv Pioneer_DailyAuth_SummaCare_20200329.csv MG 11.22.19 HospitalListReport.csv Humana COPC Census - Authorizations 3.26.20 Admits Discharges.csv Humana COPC Census - Authorizations 13.6.20 Admits Discharges.csv Humana COPC Census - Authorizations 3.26.20 Authorizations.csv Humana COPC Census - Authorizations 11.01.20 Authorizations.csv Humana COPC Census - Authorizations 2.2.20 Authorizations.csv Humana Census - Admits Discharges 20200420.csv ^0420 file bad Humana Census - Admits Discharges 20200416.csv Humana Census - Authorizations 20200416.csv'; my $regex = qr/^(?i)CHOC.*[.csv]$/mp; 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