Shell Programming and Scripting

Thanks a ton Radoulov , the code is working perfectly fine. I am sorry for the typo, it was the key : 3456 . Thanks a lot for your time.

Best Regards
Ranjani

Hi , just another quick doubt.

What do i need to do incase i want to compare the values of 2 fields as in ( the value at col 1 and value at col2 ) for the corresponding records .

Your help will be much appreciated. Thanks a lot again

Ranjani

Like this?

Code:

awk 'NR == FNR { 
  f1[$3] = $1 SUBSEP $2 
  next
  }
{ 
  print "key", 
  $3 in f1 ? $3 " records " \
  (f1[$3] == $1 SUBSEP $2 ? "" : "do not ") \
  "match" : $3 " is missing" 
  }' file2 file1

Awesome!! .. works perfect .. thanks a lot for all your help. Its much appreciated

Could I ask another doubt in addition : I hope you guys dont mind :

I would want to add a condition to check for blank records in between , as in, right now if there is any blank records , the script output : key is missing . It identifies the key as a simple space. I want it to display an error "blank record in the file". I tried doing it, but could not succeed... Need your help in this as well. Thanks a lot.

Actually I am a newbee to awk and hence finding it difficult to do the modifications.. it would be great if you could post an expalination to how this code would work so that i could understand and take it further myself.

Thanking you in advance
Ranjani

Something like this?

Code:

awk 'NR == FNR { 
  f1[$3] = $1 SUBSEP $2 
  next
  }
NF { 
  print "key", 
  $3 in f1 ? $3 " records " \
  (f1[$3] == $1 SUBSEP $2 ? "" : "do not ") \
  "match" : $3 " is missing" 
  }' file2 file1

The above code works like this:

Code:

NR == FNR { 
  f1[$3] = $1 SUBSEP $2 
  next
  }

While reading the first file - NR == FNR (the current record number of the entire input equals the current record number of the current file, this is a common AWK idiom) build the f1 associative array: the third field is the key, the first and the second fields are the value (check the awk documentation for SUBSEP, you can use FS here also). The next statement:

[from effective awk programming]

Code:

{ 
  print "key", 
  $3 in f1 ? $3 " records " \
  (f1[$3] == $1 SUBSEP $2 ? "" : "do not ") \
  "match" : $3 " is missing" 
  }

While reading the second file print the string "key", followed by the result of the following expression:

Code:

$3 in f1 ? $3 " records " (f1[$3] == $1 SUBSEP $2 ? "" : "do not ") "match" : $3 " is missing"

The if?then:else is the ternary operator, it means: if a key in the f1 array matches the third field of the current (the second) file - $3 in f1 , then print the third field followed by the string " records " followed by (another ternary operator): if the value of the previous key equals the first and the second field pair in the current file, then nothing (""), else print the string "do not " (end of the embedded second ternary operator), followed by the string "match", else (the first ternary operator) print the third field and the string " is missing".

That's all.

Perfect! .. thank a lot Radoulov... Thanks a ton for all the help!!