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30a32040d3
Adds documentation for the EQL `substring` function. Supporting changes: * Creates a new "EQL function reference" page * Updates the title of the "EQL syntax reference" page for consistency * Adds a brief "Functions" section to the EQL syntax docs * Updates EQL limitations docs to state that only array functions are unsupported
66 lines
1.4 KiB
Plaintext
66 lines
1.4 KiB
Plaintext
[[eql-function-ref]]
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== EQL function reference
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++++
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<titleabbrev>Function reference</titleabbrev>
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++++
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experimental::[]
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{es} supports the following EQL functions:
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* <<eql-fn-substring>>
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[discrete]
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[[eql-fn-substring]]
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=== `substring`
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Extracts a substring from a source string at provided start and end positions.
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If no end position is provided, the function extracts the remaining string.
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[%collapsible]
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====
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*Example*
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[source,eql]
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----
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substring("start regsvr32.exe", 6) // returns "regsvr32.exe"
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substring("start regsvr32.exe", 0, 5) // returns "start"
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substring("start regsvr32.exe", 6, 14) // returns "regsvr32"
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substring("start regsvr32.exe", -4) // returns ".exe"
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substring("start regsvr32.exe", -4, -1) // returns ".ex"
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----
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*Syntax*
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[source,txt]
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----
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substring(<source>, <start_pos>[, <end_pos>])
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----
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*Parameters*
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`<source>`::
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(Required, string)
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Source string.
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`<start_pos>`::
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+
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--
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(Required, integer)
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Starting position for extraction.
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If this position is higher than the `<end_pos>` position or the length of the
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`<source>` string, the function returns an empty string.
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Positions are zero-indexed. Negative offsets are supported.
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--
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`<end_pos>`::
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(Optional, integer)
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Exclusive end position for extraction. If this position is not provided, the
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function returns the remaining string.
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+
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Positions are zero-indexed. Negative offsets are supported.
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*Returns:* string
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==== |