OS Manuals

/usr/bin/numfmt

Cross-platform Rust rewrite of the GNU coreutils.

From uutils 0.12.0-r6 (os), captured 2026-11-07 by running numfmt --help (exit 0). permalink

Convert numbers from/to human-readable strings

Usage: numfmt [OPTION]... [NUMBER]...

Options:
      --debug                    print warnings about invalid input
      --grouping                 use locale-defined grouping of digits, for example 1,000,000 (which
                                 means it has no effect in the C/POSIX locale)
  -d, --delimiter <X>            use X instead of whitespace for field delimiter
      --field <FIELDS>           replace the numbers in these input fields; see FIELDS below
                                 [default: 1]
      --format <FORMAT>          use printf style floating-point FORMAT; see FORMAT below for
                                 details
      --from <UNIT>              auto-scale input numbers to UNITs; see UNIT below [default: none]
      --from-unit <N>            specify the input unit size [default: 1]
      --to <UNIT>                auto-scale output numbers to UNITs; see UNIT below [default: none]
      --to-unit <N>              the output unit size [default: 1]
      --padding <N>              pad the output to N characters; positive N will right-align;
                                 negative N will left-align; padding is ignored if the output is
                                 wider than N; the default is to automatically pad if a whitespace
                                 is found
      --header[=<N>]             print (without converting) the first N header lines; N defaults to
                                 1 if not specified
      --round <METHOD>           use METHOD for rounding when scaling [default: from-zero] [possible
                                 values: up, down, from-zero, towards-zero, nearest]
      --suffix <SUFFIX>          print SUFFIX after each formatted number, and accept inputs
                                 optionally ending with SUFFIX
      --unit-separator <STRING>  use STRING to separate the number from any unit when printing; by
                                 default, no separator is used
      --invalid <INVALID>        set the failure mode for invalid input [default: abort] [possible
                                 values: abort, fail, warn, ignore]
  -z, --zero-terminated          line delimiter is NUL, not newline
  -h, --help                     Print help
  -V, --version                  Print version

UNIT options:

- none: no auto-scaling is done; suffixes will trigger an error

- auto: accept optional single/two letter suffix:

    1K = 1000, 1Ki = 1024, 1M = 1000000, 1Mi = 1048576,

- si: accept optional single letter suffix:

    1K = 1000, 1M = 1000000, ...

- iec: accept optional single letter suffix:

    1K = 1024, 1M = 1048576, ...

- iec-i: accept optional two-letter suffix:

    1Ki = 1024, 1Mi = 1048576, ...

- FIELDS supports cut(1) style field ranges:

    N N'th field, counted from 1
    N- from N'th field, to end of line
    N-M from N'th to M'th field (inclusive)
    -M from first to M'th field (inclusive)
    - all fields

Multiple fields/ranges can be separated with commas

FORMAT must be suitable for printing one floating-point argument %f.
Optional quote (%'f) will enable --grouping (if supported by current locale).
Optional width value (%10f) will pad output. Optional zero (%010f) width
will zero pad the number. Optional negative values (%-10f) will left align.
Optional precision (%.1f) will override the input determined precision.
Options (18)
OptionDescriptionSource
--debugprint warnings about invalid inputhelp + man
--groupinguse locale-defined grouping of digits, for example 1,000,000 (which means it has no effect in the C/POSIX locale)help + man
-d, --delimiter Xuse X instead of whitespace for field delimiterhelp + man
--field FIELDSreplace the numbers in these input fields;help
--format FORMATuse printf style floating-point FORMAT;help + man
--from UNITauto-scale input numbers to UNITs;help
--from-unit Nspecify the input unit size [default: 1]help
--to UNITauto-scale output numbers to UNITs;help
--to-unit Nthe output unit size [default: 1]help
--padding Npad the output to N characters;help + man
--header Nprint (without converting) the first N header lines;help
--round METHODuse METHOD for rounding when scaling [default: from-zero] [possible values: up, down, from-zero, towards-zero, nearest]help
--suffix SUFFIXprint SUFFIX after each formatted number, and accept inputs optionally ending with SUFFIXhelp + man
--unit-separator STRINGuse STRING to separate the number from any unit when printing;help + man
--invalid INVALIDset the failure mode for invalid input [default: abort] [possible values: abort, fail, warn, ignore]help
-z, --zero-terminatedline delimiter is NUL, not newlinehelp + man
-h, --helpPrint helphelp + man
-V, --versionPrint versionhelp + 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.