Merge two lines of a file and adding number in the end of lines

Question

I have a large text file abc.txt with the following format:

BALT
-6.110
130.600
4.06874414
-0.03254425
BALT
-6.620
154.460
3.92286595
-0.17842244
BARM
32.740
140.680
3.94326190
-0.15802649

I need this file to convert an output file xyz.txt in the format like:

BALT 1
 -6.110 130.600
 4.06874414
 -0.03254425
BALT 2
 -6.620 154.460
 3.92286595
 -0.17842244
BARM 3
 32.740 140.680
 3.94326190
 -0.15802649

The numbers 1, 2, 3... after four character data name will increase as I go for more data.

Answer 1

Here's a oneliner:

# sed 's/^[A-Z]/>&/' abc.txt | awk -v RS='>' 'NR>1 {printf("%s %d\n %s %s\n %s\n %s\n",$1,NR-1,$2,$3,$4,$5)}' > xyz.txt

Here's the output generated:

# cat xyz.txt 
BALT 1
 -6.110 130.600
 4.06874414
 -0.03254425
BALT 2
 -6.620 154.460
 3.92286595
 -0.17842244
BARM 3
 32.740 140.680
 3.94326190
 -0.15802649

The details:

First part - the sed part of the line adds an arbitrary special character to the start of each record (a record is a name followed by 4 numbers). I picked a '>' to start the record. This makes the processing by awk easy.

Second part - For each record, just print out a new format of the fields as you specified. The only quirk is that there's an extra blank record at the start - we skip over that (NR>1).

Answer 2

There are 2 tasks: numerate apropriate line(s) than format output:

nl -bp[A-Z] -nln abc.txt | 
sed '
     /^\w/{
           s/\(.*\)\(....\)/\2 \1/
           n
           N
           s/\n\s*/ /
          }
     s/^\s*/ /
    ' > xyz.txt

Or if you like awk

awk '
     /[A-Z]/ {
             print $0, ++count
             getline
             printf " %s", $0
             next
     }
     {
             print "", $0
     }
    ' abc.txt > xyz.txt