${(m)…}: Apply MULTIBYTE support

If the MULTIBYTE option is enabled, (m) activates multibyte character width calculation.

Without option MULTIBYTE, each byte is counted as a single character.

Links

• Zsh manual on parameter expansion flags
• Zsh manual on option MULTIBYTE
• Zsh FAQ on multibyte input and output

Examples

Display width of UNICODE characters

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#!/usr/bin/env zsh [[ ! -o MULTIBYTE ]] && { echo "Missing MULTIBYTE support"; exit 1; } # 10140 GREEK ACROPHONIC ATTIC ONE QUARTER # don't use a double-quoted string, it does not apply the \U escape unicode=$'\U10140' print "Unicode character: $unicode" print "Multibyte character width: ${(m)#unicode}" # turn of option MULTIBYTE to get width in bytes set +o MULTIBYTE print "Character byte count: ${(m)#unicode}"

Output:

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Unicode character: 𐅀 Multibyte character width: 1 Character byte count: 4