Myujth

I am trying to parse the following line using sed to replace a whitespace with a newline only when the whitespace doesn't precede a colon.

For example, I'm using the following input to be processed:

label1: output label2: output2 label3: "output3" label4: output4 label5: output5 label6: output6 label7: output7 label8: output8 label9: output9 label10: output10

I'd like regex to replace any whitespace that doesn't have a colon before it with a newline, so the output would be something like this:

label1: output
label2: output2
label3: "output3"
label4: output4

label5: output5
label6: output6

label7: output7
{


label8: output8
label9: output9


label10: output10

When I try using the following regex in cat file | sed 's/[^:A-Za-z0-9"] /%/g' | tr '%' 'n', it results in the output below, which is close but not achieving the goal:

 label1: output label2: output2 label3: "output3" label4: output4
 label5: output5 label6: output6
 label7: output7


 label8: output8
 label9: output9

 label10: output10

I've also tried this cat file | sed 's/[^:A-Za-z0-9"] /%/g' | tr '%' 'n', and it results in

label1: outpu
label2: output
label3: "output3
label4: output

label5: output
label6: output

label7: output



label8: output

label9: output


label10: output10

Which looks like the regex also includes replacing every other character that's not a : with a newline.

This should do it:

sed -E 's/([^:]) /1n/g' file

Output:

label1: output
label2: output2
label3: "output3"
label4: output4

label5: output5
label6: output6

label7: output7



label8: output8

label9: output9


label10: output10

Cheers!

This might work for you (GNU sed):

sed 'G;:a;s/([^: ]) (.*(.))/132/;ta;s/.$//' file

Append a newline to the current line using the G command which by default appends an empty hold space to the pattern space. Using pattern matching and back references, iterate throughout the current line replacing a non-space/non-colon character followed by a space, by the appended newline. When there are no further matches, remove the newline artefact and print the line.

The same solution can be viewed more easily using the -r option (GNU sed only) which removes many of back slashes:

sed -r 'G;:a;s/([^: ]) (.*(.))/132/;ta;s/.$//' file

Also as pointed out, the optimal solution would be:

sed 's/([^: ]) /1n/g' file