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

/
/
gm

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "best practices "; final String string = "BEST PRACTICES – CODING STANDARDS\n\n\n" + "AUTOSYS:\n\n" + "1. NRETRY OPTION Feature - Extract jobs querying against databases should use Autosys N-retry option 3-4 times before failure.\n" + "2. Health Check job/Dummy Job/Polling Job mechanism should be designed to have better operations controls (Holding, Releasing Jobs)\n" + "3. The server names should not be hardcoded in Autosys JILs. Wide IP/ Alias/Virtual Machine names should be used.\n" + "4. Multifilewatcher concept should be pursued instead of file watcher to reduce bulk failures during planned outage.\n" + "5. Separate PROD and COB Schedules - Maintain separate Autosys jobs for PROD and COB loads, wherever DUAL LOAD mechanism exists. This will help us to HOLD/Release all the Jobs, which are connecting to a particular DB/Server.\n" + "6. Restrict # of multiple unloads from source DB using Autosys feature of controlling # of parallel jobs. Have a health check job where we are having a scenario of multiple unloads from a Database.\n" + "7. Resource concept should be used in Autosys to achieve load balancing and avoid performance bottlenecks due to high number of parallel executions.\n\n" + "8. Job Naming Convention- Job Name should specify as much info as possible. Eg,1. A short code for the project/application name, 2. Type of Job (Extract, Transformation, Load, File Watcher etc.), 3. Infra getting used (DB Name alias) \n\n" + "9. The Autosys JILs should have a comment describing the brief function of the job. \n" + " Eg: description: \"This job is to unload the data from XYZ EDW table and to load ABC folder/system\"\n" + " Description: \"This job is validates the source file and generates load ready file\"\n\n" + "10. There should not be any jobs without a box unless it is a standalone job. \n\n" + "11. Schedules should have Time dependency as well as trigger dependency (If Source is file or Source DB have trigger mechanism to mark the completion of loading of data)\n" + "12. Lookback feature should be added to avoid accidental execution of schedule by referring to the success state of previous schedule.\n" + "13. Jobs to be put on schedule only when the project is planned to be LIVE.\n" + "14. Use bulk and Intermediate mode concept based on data volume\n" + "15. Applications should not be scheduled during Green Zone \n" + "16. Projects that are obsolete in prod needs to have jobs decommissioned instead of being ON-ICE\n" + "17. Deleting Jobs - While Jobs are being decommissioned, proper dependency analysis should be done. The Box should be deleted if all the Jobs in that box is to be decommissioned.\n\n\n\n\n\n\n\n" + "TRIGGER FILES:\n\n" + "1. All the triggers and source files should be cleaned up/archived after processing. \n" + "2. Files being sent to BI should have data files and trigger file to ensure downstream receives the data file and processes it. Eg: ODS sends files to BI, each data file is accompanied with trigger file.\n\n\n\n" + "CLEANUP & UTILITY SCRIPTS:\n\n" + "File Retention Policies/Cleanup/Space Monitoring – \n" + "1. Define retention policy for every file – Input, output, intermediate, reject, error files etc.\n" + "2. Ensure the daily cleanup process is setup for every feed in production and new feeds being promoted to production based on retention policy.\n" + "3. Ensure that all new projects have space allocation done to all the required mounts / directories based on retention policy before implementation of the project to production and ensure space-monitoring scripts are available.\n" + "4. Log file locations and not coding to have any files in /tmp or any other non-project locations.\n" + "5. Auto cleanup of files including inbound, outbound, error, log, Autosys logs\n" + "6. Automated reconciliation controls in place to catch issues in data so that to avoid any manual work around and fix issues in a timely manner.\n" + "7. Reject handling frameworks- Rejects should be captured and sent to downstream/ users\n" + "8. \n\n" + "FILE HANDLING:\n\n" + "1. Header / trailers should be encouraged to assist reconciliation process and help in audit/controls .Ex: Provide record /data count in file.\n" + "2. Source file having transactional Data with Dates : A sanity check should be done to ensure that duplicate data is not being processed\n" + "3. Put controls to ensure the Files containing PII information is contained in a special directory which is not accessible and secure (Not use persistent access, but use a specialized FID)\n\n" + "AUDIT & CONTROLS:\n" + "1. NDM Jobs – Transmission controls to ensure all data has been transferred successfully\n" + "2. FID - Each Application ( Example: Global Fraud, REW, Genesis) within BI should have their own Unique FID’s for batch processing\n" + "3. Alerts – Only actionable alerts should be set up for Production Management. \n" + "4. Access permissions - As of now all Codes, parm, config, env are in FID, which is high risk. Code and environment parameters should be owned by an FID which would be accessible by only SA/Admin\n\n\n\n\n\n\n" + "EAP –\n\n" + "1. Edge node - Identify Key Players for EAP in terms of which team dictates App to use Edge Nodes, team responsible to allocate maximum space for a give App etc. Currently there are 3 Edge Nodes and all new projects are using same Edge Node - bdswr402x20d1.nam.nsroot.net. \n" + "2. Include Kerberos Authentication script in jobs to ensure continuity of job run else it will time out/terminate after 8hrs. Kerberos Authentication is at FID level so if multiple teams are using same FID, one job in any of these teams should take care of the authentication\n" + "3. CATE framework needs to be flexible to provide custom paths for applications to write their log/error files etc. For debugging purpose. Currently all Talend logs are dumped into this location /var/log/talend/.\n" + "4. All the Autosys logs should be captured in application specific edge node location. Admin should have space limit set to how much each FID can write on /home directory.\n" + "a. As per current design , Autosys logs are being captured in /home \n\n" + " std_out_file: \"/home/gcgeeapnatldp/autosyslogs/$AUTO_JOB_NAME.$AUTORUN.out\"\n" + "std_err_file: \"/home/gcgeeapnatldp/autosyslogs/$AUTO_JOB_NAME.$AUTORUN.err\"\n\n\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html