Shell Programming and Scripting

BRAAGRP1
A2X
B2X
C2X
D2X

BRBGRP12
A3X
B3X
Z10
D09

BRC1GRP2
LO01
LO02
LO03
LO09

BR11GR112
NN01
NN02
M001
M002

BRAAGRP1 	BRBGRP12	BRC1GRP2	BR11GR12
A2X       	A3X          	LO01        	NN01
B2X         	B3X          	LO02        	NN02
C2X         	Z10          	LO03        	M001
D2X        	D09          	LO09        	M002

awk '/^$/{i=0}!/^$/{i++;x=sprintf ("%-17s", $0);a[i]=a[i]""x}END{for (j=1;j<=i;j++) print a[j]}' file

awk '
/^$/{   i=0     # Set output row counter to 0 when you find an empty line.
}
!/^$/{  i++     # Increment output row counter when you find a line with data.
        x=sprintf ("%-17s", $0) # Set x to current line expanded to length 17
                                # by adding trailing spaces.
        a[i]=a[i] x     # Add expanded current line to the end of row i data.
}
END{    for(j=1;j<=i;j++) print a[j]    # Print data for each accumulated row.
}' file1        # Read input data from a file named file1.

awk '$1=$1' FS='\n' OFS='\t' RS=

BRAAGRP1        A2X     B2X     C2X     D2X
BRBGRP12        A3X     B3X     Z10     D09
BRC1GRP2        LO01    LO02    LO03    LO09
BR11GR112       NN01    NN02    M001    M002