mjhjmtu

I need to search for thousands of strings one by one if they exists on a second column and if not do action against each such string which was not found in second column of any line

file:

line a
line b
line c
line z
line d
line e
line z
line z

file2:

line a
line b
line c
line d
line e

What I tried:

$ awk 'if($2=="z") c++ END if(c==0) print "no "z"" else print c" "z"" ' file
3 "z"
$ awk 'if($2=="z") c++ END if(c==0) print "no "z"" else print c" "z"" ' file2
no "z"
$ awk 'if($2=="z") c++ END if(c!=0) print "no "z, action will be done"" ' file
no "z, action will be done"

Is my code ok, or could be simplified/optimized yet?

Update:
@RomanPerekhrest
referring to your code, how to process only "else" or add negation to "c?" and then ignore else?

I was trying with:
(c? : "no"),

but it does not work.

@αғsнιη, thank you, finally I have working script

$ awk -v s="z" '$2==s c++ END printf (!c ? NOP : "prepare command1nprepare command2nprepare command3n") ' file
prepare command1
prepare command2
prepare command3
$ awk -v s="z" '$2==s c++ END printf (!c ? NOP : "prepare command1nprepare command2nprepare command3n") ' file2
$

or

$ awk -v s="z" '$2==s c++ ENDif(c==0) printf "prepare command1nprepare command2nprepare command3n" ' file2
prepare command1
prepare command2
prepare command3
$ awk -v s="z" '$2==s c++ ENDif(c==0) printf "prepare command1nprepare command2nprepare command3n" ' file
$

Via awk dynamic variable/argument -v <var>=<value>:

Test case for string z:

awk -v s="z" '$2==s c++ END printf "%s 42%s42n", (c? c : "no"), s ' file

The output:

3 "z"

Test case for string w:

awk -v s="w" '$2==s c++ END printf "%s 42%s42n", (c? c : "no"), s ' file

The output:

no "w"

If I understood this correctly you want to check if second column has specific alphabet, if yes, so please try below awk script which will report which one is exist with corresponding count and which one doesn't with "NOT FOUND!" remark.

awk -v alphabet="$(printf "%s" a..z)" 'BEGIN split(alphabet, arr, "") 
 chrs[$2]++ END for(y in chrs) for(x in arr)
 if(arr[x] in chrs) print y, chrs[y]; delete arr[x]; break 
 else print arr[x]" NOT FOUND!"; delete arr[x] 
 
' infile

Output:

w 1
z 3
a 1
b 1
c 1
f NOT FOUND!
g NOT FOUND!
h NOT FOUND!
i NOT FOUND!
j NOT FOUND!
k NOT FOUND!
l NOT FOUND!
m NOT FOUND!
n NOT FOUND!
o NOT FOUND!
p NOT FOUND!
q NOT FOUND!
r NOT FOUND!
s NOT FOUND!
t NOT FOUND!
u NOT FOUND!
v NOT FOUND!
d 1
x NOT FOUND!
y NOT FOUND!
e 1