#printf for moonx

Support note (2026-09-05): this README is supplementary. The support record is the only capability authority; it separates native compatibility evidence from Wasm policy and smoke evidence. Options mentioned here but not promoted in that record are not compatibility guarantees.

Format and print data like printf(1):

moonx cli/printf '%s=%d\n' answer 42
moonx cli/printf '%5.2f|%-8x|%o\n' 3.14159 255 8
moonx cli/printf '%s\n' one two three   # format reused per argument
moonx cli/printf '\x41é\n'

Supported: the escapes \a \b \e \f \n \r \t \v \\ \" \' \NNN \0NNN \xHH\uHHHH \UHHHHHHHH \c (stop output); the conversions %s %c %b %d %i %u %o%x %X %f %e %E %g %G %% with flags -+ 0#, field width, and precision (width and precision accept *). %b interprets escapes in its argument. Numeric arguments accept decimal, 0x hex, leading-0 octal, and 'C for a character code. The format is reused until all arguments are consumed.

Float conversions use the exact decimal expansion of the double with round-half-even, matching GNU printf digit for digit. Use -- before a FORMAT that starts with -. Invalid numeric prefixes produce the converted prefix plus a diagnostic and status 1; the format is still repeated as needed.

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