Date: Thu, 16 May 2013 16:06:50 +0000 From: "Teske, Devin" <Devin.Teske@fisglobal.com> To: Tim Daneliuk <tundra@tundraware.com> Cc: "<freebsd-questions@freebsd.org>" <freebsd-questions@freebsd.org> Subject: Re: check variable content size in sh script Message-ID: <13CA24D6AB415D428143D44749F57D7201F4D41F@ltcfiswmsgmb26> In-Reply-To: <5194FB0A.9090400@tundraware.com> References: <5194F65F.6080503@a1poweruser.com> <5194FB0A.9090400@tundraware.com>
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On May 16, 2013, at 8:28 AM, Tim Daneliuk wrote:
> On 05/16/2013 10:08 AM, Joe wrote:
>> Hello
>>=20
>> Have script that has max size on content in a variable.
>> How to code size less than 51 characters?
>>=20
>=20
> FOO=3D"Some string you want to check length of"
> FOOLEN=3D`echo $FOO | wc | awk '{print $3}'`
>=20
Uh, without forking to 2 separate programs=85
FOOLEN=3D${#FOO}
> You can then use $FOOLEN in a conditional.
>=20
However, if the OP wanted to actually truncate $FOO to 51 characters:
NEWFOO=3D$( echo "$FOO" | awk -v max=3D51 '{print substr($0,0,max)}' )
However, if you want to handle the case of $FOO containing newlines (and yo=
u want the newline to count toward the max), then this instead would do the=
trick:
NEWFOO=3D$( echo "$FOO" | awk -v max=3D51 '
{
len =3D length($0)
max -=3D len
print substr($0,0,(max > 0 ? len : max + len))
if ( max < 0 ) exit
max--
}' )
$NEWFOO, even if multi-line, will be limited to 51-bytes (adjust max=3D51 a=
ccordingly for other desired-lengths). Newlines are preserved.
Last, but not least, if you want to be able to handle multi-line values but=
only want to return the first line up-to N bytes (using 51 as the OP used):
NEWFOO=3D$( echo "$FOO" | awk -v max=3D51 '{ print substr($0,0,max); exit }=
' )
If $FOO had multiple lines, $NEWFOO will have only the first line (and it w=
ill be truncated to 51 bytes or less).
--=20
Devin
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