stream-insert

Transform stream which insert text into the passing stream

Usage

stream-insert implements the Tranform Stream API.

var fs = require('fs');

var StreamInsert = require('stream-insert');

var insert = new StreamInsert('Line to append', /^Searched line$/);

fs.createReadStream('input.txt').pipe(insert).pipe(fs.createWriteStream('output.txt'));

API

StreamInsert(insertions, query, options)

Parameters

| Parameter | Type(s) | Required | Default | Description | | ------------ | ---------------------------------------------------- | -------- | ------- | -------------------------------------------------------------------------------------------------- | | insertions | string, string[] | Yes | | Strings to insert into the stream. | | query | object, string, string[], RegExp, RegExp[] | Yes | | Query object (see below) or RegExp(s)/string(s) used to detect where the strings will be inserted. | | options | object, string | No | {} | Additional options. If a string is passed, set the separator option. |

Query

| Filter | Type(s) | Required | Default | Description | | ------------------ | ------------------------------------------ | -------- | ------- | --------------------------------------------------------------------------------------------------------- | | searches | string, string[], RegExp, RegExp[] | Yes | | RegExp(s)/string(s) used to detect where the strings will be inserted. | | operator | string | No | AND | If AND, insert after all searches are found (sequentially). If OR, insert after each matching search. | | before | RegExp, string | No | null | Don't insert after this RegExp matched. | | after | RegExp, string | No | null | Don't insert until this RegExp matched. | | strict | boolean | No | true | In strict mode, boudaries (before & after) are not tested against searches. |

Options

| Option | Type(s) | Required | Default | Description | | ------------------ | ------------------ | -------- | ------- | --------------------------------------------------------------------------------------------------------- | | prepend | boolean | No | false | Insert strings before the last match, after otherwise. | | separator | string | No | \n | Separator used to split the stream. Default to \n to read the input stream line by line. | | limit | number | No | -1 | Maximum number of insertions (-1 for infinity). | | insertSeparator | boolean | No | true | If true, insert the separator between the insert and the matched string. |

Examples

• Insert lines into a file
• Insert words into a sentence
• Insert lines between two boundaries
• Insert a line at the end of a file
• Insert a limited number of times