# match

The `match` statement is to used search either a specified string or the contents of a named [buffer](https://olddocs.exivity.io/3.4.3/data-pipelines/extract/language/buffer) using a regular expression.

## Syntax

**`match`***`label expression target`*

## Details

The three parameters serve the following purposes:

| Parameter    | Value                                         |
| ------------ | --------------------------------------------- |
| *label*      | A unique name to associate with this match    |
| *expression* | The regular expression to apply to the target |
| *target*     | The data to search using the expression       |

### Label

The *label* associates a meaningful name to the search. Once the match has been attempted, two variables will be created or updated as follows:

| Variable           | Possible values              | Notes                                                                        |
| ------------------ | ---------------------------- | ---------------------------------------------------------------------------- |
| *`label`*`.STATUS` | `MATCH` `NOMATCH` `ERROR`    | The result of applying the expression (`ERROR` infers an invalid expression) |
| *`label`*`.RESULT` | *(A string)* *(Empty value)* | The text matched by the subgroup in the expression, if any                   |

These variables can be checked after the match in order to determine the result status and access the results.

### Expression

The regular expression must contain one or more characters enclosed in brackets - `(` ... `)` - the contents of which are termed a *subgroup*. If a successful match is made then the portion of the target text that was matched by the subgroup will be returned in the \_`label.RESULT`\_variable.

### Target

The *target* determines whether a supplied string or the contents of a named buffer are searched. By default the parameter will be treated as a string.

{% hint style="info" %}
If the string contains white-space then it must be enclosed in double quotes
{% endhint %}

If the *target* argument is surrounded with curly braces - `{` ... `}` - then it is taken to be the name of a buffer and the expression will be applied to the contents of that buffer.

{% hint style="warning" %}
Regular expressions are generally used for searching ASCII data. Searching binary data is possible but may be of limited usefulness.
{% endhint %}

### Examples

Search the contents of a variable for the text following the word 'connection:' with or without a capital 'C':

```
match varsearch "[Cc]onnection: (.*)" ${variable}
if (${varsearch.STATUS} = MATCH) {
    print Connection string is: ${varsearch.RESULT}
} else {
    print No match found
}
```

Search a text file previously retrieved from a HTTP request to locate the word 'Error' or 'error'

```
match error_check "([Ee]rror)" {text_data}
if (${error_check.STATUS} == MATCH) {
    print Found: ${error_check.RESULT}
} else {
    print No error was found
}
```