awk command giving "unterminated string" error

Question

When I am using awk command to insert a line it is giving unterminated string error.

input file is like

date      mean       rms       bias                                       
.....    .....       ....      .......                                         
.....       .....        ........           .........                         
......        ........  .......           .......

Here I need to insert new values of date, mean, rms and bias.

my script is like this

echo $PDY $mean $rms  $bias                                      
awk '/Date/ { print; print "'$PDY' \t'$mean' \t'$rms' \t'$bias'"; next }1' file.txt

Terminal log is like this

+ echo 20180131 76.196 578.177 903.000                        
20180131 76.196 578.177 903.000
+ awk '/Date/ { print; print "20180131 \t' '76.196 \t578.177 \t903.000"; next }1' file.txt                                                      
awk: /Date/ { print; print "20180131 \t
awk:                       ^ unterminated string

There is a ' ' (gap/space) coming after print; print "20180131 \t in my awk command. I don't know why it is coming

Please give me a solution.

Answer 1

Your string starts with ' and ends with the second ':

awk '/Date/ { print; print "20180131 \t'

The unterminated string from error message is "20180131 \t.

Instead, use " and escape the inner " with \":

awk "/Date/ { print; print \"20180131 \t' '76.196 \t578.177 \t903.000\"; next }1" file.txt

Answer 2

The error message means that awk doesn't like the way you are using quotation marks. Glancing at your awk statement, I would point first to your frequent use of single-quotation marks within your print statement. awk is interpreting the single-quote after \t as marking the end of your entire awk program (that you began with a single-quote after the keyword awk), and at that point there was no closing double-quote for your print command (nor a close-brace for your awk statement).

The easier way to pass variables into an awk program is to use the command-line argument -V, eg. awk -V pdy="$PDY" -V mean="$mean", and then usepdyandmeanas nativeawk` variables. With this method, there will be no need for most of your quoting.