Conditional if clause in awk

awkgawktext processing

Please consider below file:

foo,1000,boo,A
foo,1000,boo,B
foo,1001,boo,B
foo,1002,boo,D

And we have below rules:

If $2 equal 1000, $4 should be equal A
If $2 equal 1001, $4 should be equal B
If $2 equal 1002, $4 should be equal C

I want to apply the above rules to a single awk command, where if $4 does not obey, print the record.

The desired output would be:

foo,1000,boo,B
foo,1002,boo,D

I tried with:

awk -F, '{if(($2==1000 && $4!=A) || ($2==1001 && $4!=B) || ($4==1002 && $4!=C)){print $0}}'

Best Answer

Use this:

awk -F, '($2==1000 && $4!="A") || ($2==1001 && $4!="B") || ($2==1002 && $4!="C")' file

In the curvy brachets are the 3 conditions; if one of them applies the line will be printed. The conditions inside the brackets are connected with a AND, so both must apply.

Related Solutions

Awk comparison using arrays

I don't see why you would want to do it in a single awk command, what you have seems perfectly fine. Anyway, here's one way:

$ awk -F, '(max[$18]<$21 || max[$18]==""){max[$18]=$21;line[$18]=$0}
            END{for(key in line){print line[key]}}' file
6598,6598,0,1,,1,0,1,1,0,0,0,1,0,0,0,0,1390,1390,,0.730000,
1297,1297,0,0,,0,0,1,0,0,0,0,0,1,0,1,0,1707,1707,,7.000000,
6553,6553,0,1,,1,0,1,1,0,0,0,0,1,0,1,0,4326,4326,,9.000000,

The idea is very simple. We have two arrays, max has $18 as a key and $21 as a value. For every line, if the saved value for $18 is smaller than $21 or if there is no value stored for $18, then we store the current line ($0) as the value for $18 in array line. Finally, in the END{} block, we print array line.

Note that the script above treats $18 as a string. Therefore, 001 and 1 will be considered different strings.

AWK – Compare Records Value with Each Other

You can try this awk

awk -F"," 'NR != 1 { if ((x - $3) >= 50) print $0; } { x = $3 }' file

and this one if you don't want to print row if filed $1 changed:

awk -F"," 'NR != 1 { if ($1 == fc && (x - $3) >= 50) print $0; } { x = $3; fc = $1; }' file

Best Answer

Related Solutions

Awk comparison using arrays

AWK – Compare Records Value with Each Other

Related Question