replace a column values with the first value in column

UNIX for Advanced & Expert Users
1

Hi All,

I have a file which has data in following format:

"Body_Model","2/1/2007","2/1/2007"
"CSCH74","0","61"
"CSCS74","0","647"
"CSCX74","0","3"
"CSYH74","0","299"
"CSYS74","0","2514"
"CSYX74","0","3"
"Body_Model","3/1/2007","3/1/2007"
"CSCH74","0","88"
"CSCS74","0","489"
"CSCX74","0","4"
"CSYH74","0","386"
"CSYS74","0","1871"
"CSYX74","0","4"

I want to have to convert to get following :

"Body_Model","2/1/2007","2/1/2007"
"CSCH74","2/1/2007","61"
"CSCS74","2/1/2007","647"
"CSCX74","2/1/2007","3"
"CSYH74","2/1/2007","299"
"CSYS74","2/1/2007","2514"
"CSYX74","2/1/2007","3"
"Body_Model","3/1/2007","3/1/2007"
"CSCH74","3/1/2007","88"
"CSCS74","3/1/2007","489"
"CSCX74","3/1/2007","4"
"CSYH74","3/1/2007","386"
"CSYS74","3/1/2007","1871"
"CSYX74","3/1/2007","4"

Can any of Unix Gurus help me.

Thanks
Sumeet

2 
awk 'BEGIN { FS="," }
 $1 ~ /Body_Model/ { mydate=$2; print; next }
 { print $1, mydate, $3 }' file.txt
3

Glenn,
you forgot to assign the OFS.

nawk 'BEGIN { FS=OFS="," }
 $1 ~ /Body_Model/ { mydate=$2; print; next }
 { print $1, mydate, $3 }' file.txt
4

Oops! Thanks for catching that.