Question

I have a tab delimited file that contains date, header row, some values, empty row, and then it repeats all over again multiple times. The file looks something like this:

November 3, 2011
column_name1    column_name2    column_name3    column_name4
value   value   value   value
value   value   value   value
value   value   value   value
value   value   value   value

November 4, 2011
column_name1    column_name2    column_name3    column_name4
value   value   value   value
value   value   value   value
value   value   value   value
value   value   value   value

I am trying to find the right sed or awk commands to tranform the data so it could be used to create charts. I want the transformed data to look like this:

date    column_name1    column_name2    column_name3    column_name4
November 3, 2011    value   value   value   value
November 3, 2011    value   value   value   value
November 3, 2011    value   value   value   value
November 3, 2011    value   value   value   value

date    column_name1    column_name2    column_name3    column_name4
November 4, 2011    value   value   value   value
November 4, 2011    value   value   value   value
November 4, 2011    value   value   value   value
November 4, 2011    value   value   value   value

Answer 1

Awk.

BEGIN {
    FS = "\n"
    RS = "\n\n"
    OFS = "\t"
    #ORS = "\n"
}
{
    print "date" OFS $2
    for (i = 3; i <= NF; i++)
        print $1 OFS $i
    print ""
}