mjhjmtu

Using the awk command, I am to display lines 3-5 backwards of a file i have created and before the outputted line, the line number is to be displayed (i.e. line 3:). I am also to display the total wordcount of all three lines. My code is provided below. I keep obtaining an error message for the '%s' and not sure where to go from here, any help?

BEGIN print("<< Start of file >>"); 

NR>=3 && NR<=5 for (i = NF; i >= 1; i--)

 printf "%d: %s ", $i;
 print ""
 wordCount += NF;






END printf "<< End of file: wordCount = %d >>n", wordCount 

Here's the input file:

Gimme presents I want more!
Gimme presents, I did my chores!
A bicycle, a tricycle, a motor vehicle!
I deserve it, you reverse it!
Gimme presents; more, more, more
Gimme presents I need more!

And the out put i obtain is:

(FILENAME=presents FNR=3) fatal: not enough arguments to satisfy format string
 `%d: %s '
 ^ ran out for this one

Code bug portion

Key issue is that you have %d: %s format, but there's only one argument $i to match the format speficiers, i.e. $i matches with %d but not with %s.

Once you change the script as so:

#!/usr/bin/awk -f

BEGIN print("<< Start of file >>"); 

NR>=3 && NR<=5 
 for (i = NF; i >= 1; i--)
 printf "%d: %s ", i,$i;
 print ""
 wordCount += NF;




END printf "<< End of file: wordCount = %d >>n", wordCount 

Then there's no error, and produces output as so:

$ ./awk_script.awk input.txt
<< Start of file >>
7: vehicle! 6: motor 5: a 4: tricycle, 3: a 2: bicycle, 1: A 
6: it! 5: reverse 4: you 3: it, 2: deserve 1: I 
5: more 4: more, 3: more, 2: presents; 1: Gimme 
<< End of file: wordCount = 18 >>

Fixing code to match desired behavior

However, your description was:

I am to display lines 3-5 backwards of a file i have created and before the outputted line, the line number is to be displayed (i.e. line 3:)

That means before processing each field using for-loop, you need to output line number first:

#!/usr/bin/awk -f

BEGIN print("<< Start of file >>"); 

NR>=3 && NR<=5 
 printf "line %d:",NR; # display line number first
 for (i = NF; i >= 1; i--)
 printf " %s ", $i;
 print ""; 
 wordCount += NF;



END printf "<< End of file: wordCount = %d >>n", wordCount 

Which works as so:

$ ./awk_script.awk input.txt
<< Start of file >>
line 3: vehicle! motor a tricycle, a bicycle, A 
line 4: it! reverse you it, deserve I 
line 5: more more, more, presents; Gimme 
<< End of file: wordCount = 18 >>