strlen

Synopsis

$strlen(<string>)

Technical

Determines the length of the entire argument in Unicode code points for valid UTF-8 text. Spaces, literal quotation marks, and formatting/control characters are included. There is no word parsing or special JSON form.

The count is not a byte length, screen width, or count of displayed graphemes: a combining mark counts separately, and a wide character counts as one. Use printlen to measure display columns.

Practical

Use this function to measure literal text, function results, or automatic expandos. For ASCII text, its count agrees with $@var; for multibyte UTF-8 text, $@var counts bytes and can differ from strlen.

Returns

A decimal integer: the number of code points, or 0 for empty input. There are no options, settings, or server requirements.

The implementation performs a quick count without validating UTF-8: every byte below 0x80 or at least 0xC0 counts once, and bytes 0x80 through 0xBF do not count. Malformed text therefore need not produce a meaningful character count. isutf8 performs a separate structural check, with its own limitations; it is not strict Unicode validation.

Examples

$strlen($1-3)            Returns the length of arguments $1 through $3, including spaces.
$strlen(epic is cool)    Returns 12.
$strlen(café)            Returns 4 for UTF-8 text.
$strlen(界)              Returns 1, regardless of its display width.
$strlen()                Returns 0.

Source

Handler: source/functions.c. Counting: quick_code_point_count. The $@ byte count is implemented in source/expr.c.