How to pass bash parameter to awk script? - file

Question

I have awk file:
#!/bin/awk -f
BEGIN {
}
{
filetime[$'$colnumber']++;
}
END {
for (i in filetime) {
print filetime[i],i;
}
}
And bash script:
#!/bin/bash
var1=$1
awk -f myawk.awk
When I run:
ls -la | ./countPar.sh 5
I receive error:
ls -la | ./countPar.sh 5
awk: myawk.awk:6: filetime[$'$colnumber']++;
awk: myawk.awk:6: ^ invalid char ''' in expression
Why? $colnumber must be replaced with 5, so awk should read 5th column of ls ouput.
Thanks.

Answer 1

You can pass variables to your awk script directly from the command line.
Change this line:
filetime[$'$colnumber']++;
To:
filetime[colnumber]++;
And run:
ls -al | awk -f ./myawk.awk -v colnumber=5
If you really want to use a bash wrapper:
#!/bin/bash
var1=$1
awk -f myawk.awk colnumber=$var1
(with the same change in your script as above.)
If you want to use environment variables use:
#!/bin/bash
export var1=$1
awk -f myawk.awk
and:
filetime[ENVIRON["var1"]]++;
(I really don't understand what the purpose of your awk script is though. The last part could be simplified to:
END { print filetime[colnumber],colnumber; }
and parsing the output of ls is generally a bad idea.)

Answer 2

The easiest way to do it:
#!/bin/bash
var=$1
awk -v colnumber="${var}" -f /your/script
But within your awk script, you don't need the $ in front of colnumber.
HTH

Answer 3

Passing 3 variable to script myscript.sh
var1 is the column number on which condition has set.
While var2 & var3 are input and temp file.
#!/bin/ksh
var1=$1
var2=$2
var3=$3
awk -v col="${var1}" -f awkscript.awk ${var2} > $var3
mv ${var3} ${var2}
execute it like below -
./myscript.sh 2 file.txt temp.txt