Command
	len

Purpose
	Editor - Line enumerator or counter

Aliases
	lineenumerator, lineenum, len

Syntax
	len [ <options> ] <input_string>

Options
	-e	Count empty lines. Without this option, empty lines are not
		considered.

	-c	Case insensitive. Case will be ignored when considering separator
		characters.

Arguments
	<input_string>
		The input string on which this command will operate. It
		can be specified as a str constant or str variable or an
		expression resulting in a str value.

		If a str constant is used, we highly recommend using
		double quotes around it, such as "John Doe".
		Without the double quotes, the spaces in the input string
		will produce errors or erroneous output.
		

Stream Input	
	Stream input is ignored.

Stream Output
	The number of lines found are written here.

Stream Error
	Any errors are listed here.

Description
	The command enumerates (or counts) lines in the <input_string> and
	writes the count to the stream output or redirected stream output.

	The command CAN ALSO BE USED WITH FILES. Simply read in the contents
	of the file using the repro command into a str variable, then use that
	str variable as <input_string>.

	The command uses system variable $lsep. This variable lists line separators.
	Each character in $lsep is assumed to end a line. See help page for systemvar
	for details on this system variable.

	You are free to change the values of any system variables. It is, however, highly
	recommended that you restore their values to their previous values. This can be
	done as follows.

	# Save previous value.
	var str saved_lsep
	set $saved_lsep = $lsep

	set $lsep = < new_value >
	...
	< DO_your_stuff >
	...

	# Restore value
	set $lsep = $saved_lsep

	System variables are used by many commands, and incorrect setting of their values
	may affect the operation of these commands.
		
Restrictions
	None.

Valid Examples
	Assume that you want to count lines in a file myfile.js.

	var str content
	repro myfile.js >$content
	len -e $content

	The above code will produce the number of all lines (including empty lines)
	in file myfile.js.

	To count just the non-empty lines, do NOT use the -e option, as follows.

	len $content
	
Invalid Examples

	len "myfile.js"

	Will produce 1. That's because myfile.js will be taken verbatim as
	<input_string>, and there is only one line in that string.

	len { repro "myfile.js" }

	Will also produce erroneous results. The inline command { repro "myfile.js" }
	will execute and bring out its output as part of the len command.
	The len comand will then consider the first word of the output as <input_string>.
	So, if the first line of myfile.js is empty, since we did not specify -e option,
	the output of the len command will be 0. If the first line of myfile.js is not
	an empty line, the output of the len command will be 1.

	To correctly count the number of lines in myfile.js, use the code listed
	above under Valid Examples.

See Also
systemvar
var
echo
escape
lex
lin
lap
lal
sen
wen
chen