OS Manuals

/usr/bin/idn2

libidn2 (CLI utilities)

From idn2-utils 2.3.8-r12 (os), captured 2026-11-05 by running idn2 --help (exit 0). permalink

Usage: /usr/bin/idn2 [OPTION]... [STRINGS]...
Internationalized Domain Name (IDNA2008) convert STRINGS, or standard input.

Command line interface to the Libidn2 implementation of IDNA2008.

All strings are expected to be encoded in the locale charset.

To process a string that starts with `-', for example `-foo', use `--'
to signal the end of parameters, as in `idn2 --quiet -- -foo'.

Mandatory arguments to long options are mandatory for short options too.
  -h, --help                Print help and exit
  -V, --version             Print version and exit
  -d, --decode              Decode (punycode) domain name
  -l, --lookup              Lookup domain name (default)
  -r, --register            Register label
  -T, --tr46t               Enable TR46 transitional processing
  -N, --tr46nt              Enable TR46 non-transitional processing
      --no-tr46             Disable TR46 processing
      --usestd3asciirules   Enable STD3 ASCII rules
      --no-alabelroundtrip  Disable A-label roundtrip for lookups
      --debug               Print debugging information
      --quiet               Silent operation

Report bugs to: help-libidn@gnu.org
Libidn2 home page: <https://www.gnu.org/software/libidn/#libidn2>
General help using GNU software: <https://www.gnu.org/gethelp/>
Options (12)
OptionDescriptionSource
-h, --helpPrint help and exithelp + man
-V, --versionPrint version and exithelp + man
-d, --decodeDecode (punycode) domain namehelp + man
-l, --lookupLookup domain name (default)help + man
-r, --registerRegister labelhelp + man
-T, --tr46tEnable TR46 transitional processinghelp + man
-N, --tr46ntEnable TR46 non-transitional processinghelp + man
--no-tr46Disable TR46 processinghelp + man
--usestd3asciirulesEnable STD3 ASCII ruleshelp + man
--no-alabelroundtripDisable A-label roundtrip for lookupshelp + man
--debugPrint debugging informationhelp + man
--quietSilent operationhelp + man

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.