# printf

respects locale, may have to set `LC_NUMERIC=C` to get internationally agreed
behaviour.

# format placeholder syntax

    %[parameter][flags][width][.precision][length]type

## parameter

`n$`, specify parameter position, missing in shells and gnu coreutils `printf`.

## flags

-   `-`: left align
-   `+`: sign positive numbers as well
-   ` `: don't sign positive numbers but prepend space
-   `0`: in conjunction w/ `width`, pad w/ zeroes instead of spaces
-   `#`: `g`: include trailing zeroes, `e`, `f`, `g`: include decimal point,
    `o`, `x`: prepend w/ `0` or `0x`

## width

minimum width of output. allows dynamic value w/ `*`.

## precision

maximum limit, for floating point round digitsafter decimal point, for string
truncate. allows dynamic value w/ `*`. following examples behave same.

    printf '%.2f' 42.239
    printf '%.*f' 2 42.239

## length

can be omitted.

## type

-   `d`, `i`: signed int as decimal, behave same
-   `u`: unsigned int as decimal
-   `f`, `F`: double as fixed point, uses lower- or uppercase on inf and NaN
-   `e`, `E`: exponent notation, `1 == 1.000000e+00`, `10 == 1.000000e+01`
-   `g`, `G`: shorten, `f` or `e` whichever applies best, omit traling zeroes
-   `x`, `X`: unsigned int as hex, use lower- or uppercase
-   `o`: unsigned int as octal
-   `s`: string
-   `c`: char
-   `a`, `A`: double in hex