Re: echo $'\0' >a does not write the nul byte

[Chet Ramey]

On 1/17/21 3:05 PM, hans@artax.karlin.mff.cuni.cz wrote:

> Description:
>         Command
>                 echo $'\0' |od -c
>         writes
>                 0000000  \n
>                 0000001
>         in contrast to
>                 echo $'\1' |od -c
>                 0000000 001  \n
>                 0000002
>         The nul byte is not echoed by $'\0'.
>
> Repeat-By:
>         echo $'\0' |od -c
>         echo $'\1' |od -c

Shell builtin commands obey the same argv conventions as any other Unix
program: arguments are null-terminated strings. That means that

echo $'\0'
echo ''
echo ""

are all equivalent, and none of them will output a null byte.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/