--- title: "Regex Pattern Scanner" description: "extract symbol values from a files using regular expressions" source: "https://github.com/log-10x/modules/tree/main/pipelines/compile/modules/scanner/pattern/module.yaml" icon: "material/regex" --- Extracts [symbol](https://doc.log10x.com/run/transform/structure/#symbols) values from text files using regular expressions. Use this scanner as a fallback for file formats not supported by language-specific scanners. ## :material-wrench-outline: Config Files To configure the Regex pattern scanner module, [:material-cog: Edit](https://doc.log10x.com/config/app/#module-config "Learn how to edit app and module configurations") these files. Below is the default configuration from: [pattern/config.yaml](https://github.dev/log-10x/config/blob/main/pipelines/compile/scanners/pattern/config.yaml "pattern/config.yaml"){target="\_blank"}.
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```yaml # 🔟❎ 'compile' pattern quoted strings configuration # This pattern symbol scanner extracts single and double quoted string values # from target files. This pattern is used a default for capturing symbol values # from source files for which no ANTLR grammar or built-in scanner is available. # Set the 10x pipeline to 'compile' tenx: compile # ============================== Pattern Options ============================== pattern: # 'fileFilter' is set as a sink for prominent source code files. Available built-in and ANTLR # scanners will take precedence over this pattern scanner - fileFilter: \b\w+\.(java|cs|php|cpp|cxx|c|h|H|hxx|cc|hh|py|go|js|rs|bash|scala|sc|ts|rb|kt|lua|groovy|swift)\b extractQuotes: true # 'lineFilter' defines a regex pattern applied to each line within a target file. # Each matching region will be extracted as symbol value lineFilter: null # 'matchContext' sets the source context to assign any symbols collected using this this pattern selector. # For possible values, see https://doc.log10x.com/run/transform/symbol/#contexts matchContext: method_invoke # 'unescapeScheme' specifies an unescape algorithm to apply to matching sequences of patternLineFilter. # Supported values: [json,java,xml,html,javaScript]. unescapeScheme: java ``` ## :material-menu: Options Specify the options below to [configure](/config "configure") multiple Regex pattern scanner: |Name|Description| |---|---| |[patternFileFilter](#patternfilefilter "file name filter regx pattern")|File name filter regx pattern| |[patternLineFilter](#patternlinefilter "file line filter regx pattern")|File line filter regx pattern| |[patternExtractQuotes](#patternextractquotes "extract single and double quoted values")|Extract single and double quoted values| |[patternMatchContext](#patternmatchcontext "output symbol context")|Output symbol context| |[patternUnescapeScheme](#patternunescapescheme "unescape scheme to apply to matching sequences")|Unescape scheme to apply to matching sequences| ### :material-menu-right-outline:**`patternFileFilter`** File name filter regx pattern. |Type|Required| |---|---| |String|✔| Defines a regex pattern a file name must match for this scanner to be applied to its contents. ### :material-menu-right-outline:**`patternLineFilter`** File line filter regx pattern. |Type|Default| |---|---| |String|""| Defines a regex pattern applied to each line within a target file where each matching region will be extracted as symbol value. NOTE: Take into consideration performance implications of the input expression to avoid long processing time and/or errors. ### :material-menu-right-outline:**`patternExtractQuotes`** Extract single and double quoted values. |Type|Required| |---|---| |Boolean|✔| Defines whether to extract single and double quoted values from input lines, taking into consideration escaping and improperly closed quotations. This options provides am efficient method for extracting string constants from input files without relying on regex backtracking. To learn more see \[pseudo code\] (https://gist.github.com/talwgx/d31133f6278bb8b640baf050f78047d5). ### :material-menu-right-outline:**`patternMatchContext`** Output symbol context. |Type|Default| |---|---| |String|""| sets the source context to assign any symbols collected using this this pattern selector. For possible values, see symbol [contexts](https://doc.log10x.com/run/transform/symbol/#contexts). If a target input line contains matches for [patternLineFilter](https://doc.log10x.com/compile/scanner/pattern/#patternlinefilter "file line filter regx pattern") AND this value is set to [method](https://doc.log10x.com/run/transform/symbol/#method) AND the matching line contains values specified as [logmethods](https://doc.log10x.com/compile/scanner/logMethods/#logmethods "names of source code methods to mark as 'logging'") or [logstreams](https://doc.log10x.com/compile/scanner/logMethods/#logstreams "names of source code variables to mark as 'logging'") outside of match bounds then the context will be set as [log](https://doc.log10x.com/run/transform/symbol/#log). For example, for the following input line, a pattern scanner set to `method` that extracts quoted strings will assigned the extracted value's context as `log` given the presence of the `Console` value which is defined as logging stream identifier. ```cs Console.WriteLine("Accounting \"service started"); ``` ### :material-menu-right-outline:**`patternUnescapeScheme`** Unescape scheme to apply to matching sequences. |Type|Default| |---|---| |String|""| Specifies an unescape algorithm to apply to matching sequences of [patternLineFilter](https://doc.log10x.com/compile/scanner/pattern/#patternlinefilter "file line filter regx pattern"). Supported values: \[json,java,xml,html,javaScript\]. If not specified, characters are treated as not escaped. To learn more see [Unescape algorithms](https://www.unbescape.org/usingunbescape.html){target="\_blank"}.
:material-github: This module is defined in [pattern/module.yaml](https://github.com/log-10x/modules/tree/main/pipelines/compile/modules/scanner/pattern/module.yaml "pattern/module.yaml"){target="\_blank"}.