Need some help with text manupulation

[Senthil Kumar .A_1]

Filename active.txt is the original file and Filename active.new.txt contains the desired o/p.

In the file ALPHA , BETA , KAPPA are the group names and the ip address and other text just below these group names are specs related to them.

ALPHA <--- group name
169.0.1.6:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD <---spec data
169.0.1.8:KRCJFWRT01:KRCJFWRT01:HGYUE9054256NFVD <---spec data

BETA
169.0.1.9:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD
169.0.1.10:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD

Could you please help me make a script which can take the file active.txt as input file like below:

cat active.txt

and perform some editing on the file such that
the the group name which is over the top of the spec data should get embedded with each line of spec data . like this


ALPHA:169.0.1.6:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD
ALPHA:169.0.1.8:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD

BETA:169.0.1.9:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD
BETA:169.0.1.10:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD

[Steve Lewis · Accepted solution]

awk -F: '{if(NF==1)g=$1;if(NF>1)printf("%s:%s\n",g,$0)}' active.txt

gives this:
ALPHA:169.0.1.6:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD
ALPHA:169.0.1.8:KRCJFWRT01:KRCJFWRT01:HGYUE9054256NFVD
BETA:169.0.1.9:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD
BETA:169.0.1.10:HSJFNEI43:HSJFNEI43:HGYUE9054256NFVD

[Senthil Kumar .A_1]

Thanks Steve, Your response was right on target.