Help with Awk Syntax

Shell Programming and Scripting
1

I have written many awk commands which go in multiple lines.
I have this confusion many times.
Some time they work if i dont terminate them with "\" but some time error.
Some time in "if" statements between if and else if i dont use ";" it gives error but sometimes it doesnt.

The below code if i dont use ";" it gives error.

    nawk -F"|" 'NR==FNR{a[$1]=$7 OFS $6;next}  {\
 if (a[$2]) \
     print $1 OFS a[$2]; \
        else \
     print $1  OFS $3}'  OFS="|" \
    file1 file2

In the below code i am not using ";" between if and else if but it works

   nawk -F"|" '{ \
 if ($3 ~ "hm." && $5 == "" && $6 == "" && $7 == "") \
     {$9="Not";print $1,$2,$8,$9 } \
 else if ($3 !~ "hm." && $5 == "" && $6 == "" && $7 == "") \
     {$9="yes";print $1,$2,$8,$9} \
 else {print $1,$2,$3,$7,$8}}' OFS="," \
   file

Appreciate help in clarifing where to use ";" and "\'

2

Why are you using backslashes?

Get rid of them all.

3

If we break a single command to multiline then are we not suppose to use "\" at end of each line

4

Yes, for command lines but not in awk scripts.

5

The backslash is needed in awk, as in the shell, when the line would be taken as a complete command if the backslash were not there.

As if (condition) is not complete, there is no need for a backslash.