I have a little test file containing:
awk this
and not awk this
but awk this
so do awk this
And I've tried the following awk commands, in bash, but each produces no output:
f=awk; awk '/$f/ && !/not/' test.txt
f=awk; awk '/\$f/ && !/not/' test.txt
f=awk; awk '/"$f"/ && !/not/' test.txt
f=awk; awk -v f="$f" '/f/ && !/not/' gtest.txt
Using double quotes " produces "event not found" error in the shell due to the !.
How can I search on a variable and negate another string in the same command?
Use awk like this:
f='awk'
awk -v f="$f" -v n='not' '$0 ~ f && $0 !~ n' file
awk this
but awk this
so do awk this
Or if you don't want to pass n='not' to awk:
awk -v f="$f" '$0 ~ f && $0 !~ /not/' file
awk this
but awk this
so do awk this
awk points to gawk for me and the following worked just fine:
awk -vf=awk '$0 ~ f && !/not/' file
I have this file
goodtime 20:30 21:40
badtime 19:52 24:00
and when I enter for example 21:00 and 21:15 I should get goodtime
So here's my script
#!/bin/sh
last > duom.txt
grep -F 'stud.if.ktu.lt' duom.txt > ktu.txt
echo "Nurodykite laiko intervala "
read h
read min
read h2
read min2
awk '{if ($2 ~ /$h.$m/ && $3 ~ /$h2.$min2/) print $1}' data.txt
But I don't get any results.
The problem with this:
awk '{if ($2 ~ /$h.$m/ && $3 ~ /$h2.$min2/) print $1}' data.txt
Is that you're trying to use shell variables in a single quoted string. You need to pass the shell variables into awk with its -v option:
awk -v patt1="$h.$min" -v patt2="$h2.$min2" '
$2 ~ patt1 && $3 ~ patt2 {print $1}
' data.txt
But, given your sample input, this will not match anything.
Until your requirements are clarified, I can't help with the logic.
I would like to use awk for a variable
that has the form abc,def
I also don't know how to use awk for a variable instead of a file
I tried the following but it doesn't works
awk -F, '{$1" "$2}' $varand
awk -F, '{$1" "$2}' "$var"
Use a herestring
awk 'commands' <<< "$string"
Also if you want to print the first two fields of a comma separated string, change the command to
awk -F, '{print $1, $2}' <<< "$string"
You can do something like this:
echo "$variable" | awk -F, '{print $1 " " $2}'
I spent on this 2 hours and get nothing. I want to get $1 and $2 as a first command line input of shell script, but I couldn't manage this. And $3 and $0 would be columns in awk. I try different methods but nothing works for me.
awk -F':' -v "limit=1000" '{ if ( $3 >=limit ) gsub("~/$1/",~/$2/); print \$0}' file.txt
the cleanest method is to explicitly pass the values from shell to awk with awk's -v option:
awk -F: -v limit=1000 -v patt="~/$1/" -v repl="~/$2/" '
$3 >=limit {gsub(patt,repl); print}
' file.txt
When your awk line is part of a script file, and you want to use $1 and $2 from the script in your awk command, you should temporary stop the literal string with a single quote and start it again.
awk -F':' -v "limit=1000" '{ if ( $3 >=limit ) gsub("~/'$1'/",~/'$2'/); print $0}' file.txt
You didn't post any sample input or expected output so this is a guess but you probably want something like this:
awk -F':' -v limit=1000 -v arg1="$1" -v arg2="$2" '$3 >= limit{gsub("~/" arg1 "/","~/" arg2 "/"); print}' file.txt
assume I have a string
"1,2,3,4"
Now I want to replace, e.g. the 3rd field of the string by some different value.
"1,2,NEW,4"
I managed to do this with the following command:
echo "1,2,3,4" | awk -F, -v OFS=, '{$3="NEW"; print }'
Now the index for the column to be replaced should be passed as a variable. So in this case
index=3
How can I pass this to awk? Because this won't work:
echo "1,2,3,4" | awk -F, -v OFS=, '{$index="NEW"; print }'
echo "1,2,3,4" | awk -F, -v OFS=, '{$($index)="NEW"; print }'
echo "1,2,3,4" | awk -F, -v OFS=, '{\$$index="NEW"; print }'
Thanks for your help!
This might work for you:
index=3
echo "1,2,3,4" | awk -F, -v OFS=, -v INDEX=$index '{$INDEX="NEW"; print }'
or:
index=3
echo "1,2,3,4" | sed 's/[^,]*/NEW/'$index
Have the shell interpolate the index in the awk program:
echo "1,2,3,4" | awk -F, -v OFS=, '{$'$index'="NEW"; print }'
Note how the originally single quoted awk program is split in three parts, a single quoted beginning '{$', the interpolated index value, followed by the single quoted remainder of the program.
Here's a seductive way to break the awkwardness:
$ echo "1,2,3,4" | sed 's/,/\n/g' | sed -e $index's/.*/NEW/'
This is easily extendable to multiple indexes just by adding another -e $newindex's/.*/NEWNEW/'
# This should be faster than awk or sed.
str="1,2,3,4"
IFS=','
read -a f <<< "$str"
f[2]='NEW'
printf "${f[*]}"
With plain awk (I.E. Not gawk etc) I believe you'll have to use split( string, array, [fieldsep] ); change the array entry of choice and then join them back together with sprintf or similar in a loop.
gawk allows you to have a variable as a field name, $index in your example. See here.
gawk is usually the default awk on Linux, so change your invocation to gawk "script" and see if it works.