if and only if condition in awk statement - awk

This is the wrong syntax but if I wanted to something where the action is done if and only if both conditions are met, how would I do this in awk?
I've tried:
awk '{if($1<=28.25&&$2<=28.25){print $0}}'
but failed.

Awk uses { print $0 } as a default action, so you can simply write:
awk -F, '$1 <= 28.25 && $2 <= 28.25' inputFile
An omitted action is equivalent to { print $0 }

Related

Awk syntax error with time layout from logs

I'm getting an syntax error with awk when I'm doing this one liner :
awk '{ if ($3 == '16' && $4 == '23:59:44') {print $0} }' /var/log/radius/radius.log
it gives me a syntax error from the time field. However, when I'm doing:
awk '{ print $4 }' /var/log/radius/radius.log
this gives me the proper format for the time hh:mm:ss so I don't understand why it doesn't work from my one liner ?
Cheers!
Single quotes ' should be used to start and end the awk's main program, you should use " instead here for comparison.
OP's code fix:
awk '{ if ($3 == 16 && $4 == "23:59:44") {print $0} }' Input_file
OR above could be shorten to(awk sh way to do):
awk '($3 == 16 && $4 == "23:59:44")' Input_file

While Read and AWK to Change Field

I have two files - FileA and FileB. FileA has 10 fields with 100 lines. If Field1 and Field2 match, Field3 should be changed. FileB has 3 fields. I am reading in FileB with a while loop to match the two fields and to get the value that should be use for field 3.
while IFS=$'\t' read hostname interface metric; do
awk -v var1=${hostname} -v var2=${interface} -v var3=${metric} '{if ($1 ~ var1 && $2 ~ var2) $3=var3; print $0}' OFS="\t" FileA.txt
done < FileB.txt
At each line iteration, this prints FileB.txt with the single line that changed. I only want it to print the line that was changed.
Please Help!
It's a smell to be calling awk once for each line of file B. You should be able to accomplish this task with a single pass through each file.
Try something like this:
awk -F'\t' -v OFS='\t' '
# first, read in data from file B
NR == FNR { values[$1 FS $2] = $3; next }
# then, output modified lines from matching lines in file A
($1 FS $2) in values { $3 = values[$1 FS $2]; print }
' fileB fileA
I'm assuming that you actually want to match with string equality instead of ~ pattern matching.
I only want it to print the line that was changed.
Simply put your print $0 statement to if clause body:
'{if ($1 ~ var1 && $2 ~ var2) { $3=var3; print $0 }}'
or even shorter:
'$1~var1 && $2~var2{ $3=var3; print $0 }'

Find "complete cases" with awk

Using awk, how can I output the lines of a file that have all fields non-null without manually specifying each column?
foo.dat
A||B|X
A|A|1|
|1|2|W
A|A|A|B
Should return:
A|A|A|B
In this case we can do:
awk -F"|" -v OFS="|" '$1 != "" && $2 != "" && $3 != "" && $4 != "" { print }' foo.dat
But is there a way to do this without specifying each column?
You can loop over all fields and skip the record if any of the fields are empty:
$ awk -F'|' '{ for (i=1; i<=NF; ++i) { if (!$i) next } }1' foo.dat
A|A|A|B
if (!$i) is "if field i is not non-empty", and 1 is short for "print the line", but it is only hit if next was not executed for any of the fields of the current line.
Another in awk:
$ awk -F\| 'gsub(/[^|]+(\||$)/,"&")==NF' file
A|A|A|B
print record if there are NF times | terminating (non-empty, |-excluding) strings.
awk '!/\|\|/&&!/\|$/&&!/^\|/' file
A|A|A|B

Can someone help me getting average of a column using awk with condition on other column

awk -F, '{if ($2 == 0) awk '{ total += $3; count++ } END { print total/count }' CLN_Tapes_LON; }' /tmp/CLN_Tapes_LON
awk: {if ($2 == 0) awk {
awk: ^ syntax error
bash: count++: command not found
Just for fun, let's look at what's wrong with your original version and transform it into something that works, step by step. Here's your initial version (I'll call it version 0):
awk -F, '{if ($2 == 0) awk '{ total += $3; count++ } END { print total/count }' CLN_Tapes_LON; }' /tmp/CLN_Tapes_LON
The -F, sets the field separator to be the comma character, but your later comment seems to indicate that the columns (fields) are separated by spaces. So let's get rid of it; whitespace-separation is what awk expects by default. Version 1:
awk '{if ($2 == 0) awk '{ total += $3; count++ } END { print total/count }' CLN_Tapes_LON; }' /tmp/CLN_Tapes_LON
You seem to be attempting to nest a call to awk inside your awk program? There's almost never any call for that, and this wouldn't be the way to do it anyway. Let's also get rid of the mismatched quotes while we're at it: note in passing that you cannot nest single quotes inside another pair of single quotes that way: you'd have to escape them somehow. But there's no need for them at all here. Version 2:
awk '{if ($2 == 0) { total += $3; count++ } END { print total/count } }' /tmp/CLN_Tapes_LON
This is close but not quite right: the END block is only executed when all lines of input are finished processing: it doesn't make sense to have it inside an if. So let's move it outside the braces. I'm also going to tighten up some whitespace. Version 3:
awk '{if ($2==0) {total+=$3; count++}} END{print total/count}' /tmp/CLN_Tapes_LON
Version 3 actually works, and you could stop here. But awk has a handy way of specifying to run a block of code only against lines that match a condition: 'condition {code}' So yours can more simply be written as:
awk '$2==0 {total+=$3; count++} END{print total/count}' /tmp/CLN_Tapes_LON
... which, of course, is pretty much exactly what John1024 suggested.
$ awk '$2 == 0 { total += $3; count++;} END { print total/count; }' CLN_Tapes_LON
3
This assumes that your input file looks like:
$ cat CLN_Tapes_LON
CLH040 0 3
CLH041 0 3
CLH042 0 3
CLH043 0 3
CLH010 1 0
CLH011 1 0
CLH012 1 0
CLH013 1 0
CLH130 1 40
CLH131 1 40
CLH132 1 40
CLH133 1 40
Thought I'd try to do this without awk. Awk is clearly the better choice, but it's still a one-liner.
bc<<<"($(grep ' 0 ' file|tee >(wc -l>i)|cut -d\ -f3|tr '\n' '+')0)/"$(<i)
3
It extracts lines with 0 in the second column with grep. This is passed to tee for wc -l to count the lines and to cut to extract the third column. tr replaces the new lines with "+" which is put over the number of lines (i.e., "12 / 4"). This is then passed to bc.

print unique lines based on field

Would like to print unique lines based on first field , keep the first occurrence of that line and remove duplicate other occurrences.
Input.csv
10,15-10-2014,abc
20,12-10-2014,bcd
10,09-10-2014,def
40,06-10-2014,ghi
10,15-10-2014,abc
Desired Output:
10,15-10-2014,abc
20,12-10-2014,bcd
40,06-10-2014,ghi
Have tried below command and in-complete
awk 'BEGIN { FS = OFS = "," } { !seen[$1]++ } END { for ( i in seen) print $0}' Input.csv
Looking for your suggestions ...
You put your test for "seen" in the action part of the script instead of the condition part. Change it to:
awk -F, '!seen[$1]++' Input.csv
Yes, that's the whole script:
$ cat Input.csv
10,15-10-2014,abc
20,12-10-2014,bcd
10,09-10-2014,def
40,06-10-2014,ghi
10,15-10-2014,abc
$
$ awk -F, '!seen[$1]++' Input.csv
10,15-10-2014,abc
20,12-10-2014,bcd
40,06-10-2014,ghi
This should give you what you want:
awk -F, '{ if (!($1 in a)) a[$1] = $0; } END '{ for (i in a) print a[i]}' input.csv
typo there in syntax.
awk '{ if (!($1 in a)) a[$1] = $0; } END { for (i in a) print a[i]}'