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