Need to parse a double entry table with two pairs

Question

I have this two-entry table resulting from a program output:

Variable1  : Value1  
Variable2  : Value2  
Variable3  : Value3  
Variable4  : Value4  
Variable5  : Value5  
Variable6  : Value6  
Variable7  : Value7 

I need to extract both the first and the fifth pairr\s, something I do with grep:

$ {program command} | grep -e Variable1 -e Variable5

resulting in this output:

Variable1  : Value1  
Variable5  : Value5  

The problem here is that I need both pairs on the same line but the grep -e command prints a LF/CR after every -e; I need the four pairs in the same line to make a final sort based on file size. I think I could make this in awk or perl from the same command line but alas I'm still somewhat green with them.

Any ideas? Thanks in advance.

Answer 1

If you just want to join the lines use tr to delete the newline:

$ {program command} | grep -e Variable1 -e Variable5 | tr -d '\n'

To do the whole thing in awk:

$ {program command} | awk '/Variable[15]/ { printf("%s ", $0) }'

Same in sed:

$ {program command} | sed -n '/Variable[15]/H; $ { x; s/\n/ /g; p }'

Answer 2

If you just want join both lines from grep, the easiest way is to pipe through fmt.

$ {program command} | grep -e Variable1 -e Variable5 | fmt

If the lines are too long, use the -w LINELENGTH option of fmt.

Answer 3

You can remove the newline by Perl's substitution

perl -ne 's/\n/ /; print if /Variable[15]/'

If you need a newline at the end, add

perl -ne 's/\n/ /; print if /Variable[15]/ }{ print "\n"'