awk : how to use variable value

Question

I want to declare a variable called variableToUse which holds the file name path. I want to append file name with today's date. Below code is in myAWK.awk

$bash: cat myAWK.awk
    BEGIN{
    today="date +%Y%m%d";
    variableToUse=/MainDir/MainDir1/MainDir2/OutputFile_today.xml
    }

    /<record / { i=1 }
    i { a[i++]=$0 }
    /<\/record>/ {
        if (found) {
             print a[i] >> variableToUse
        }
    }

I am getting syntax error at OutputFile_today.xml.

How to use variable value?

nu11p01n73R · Accepted Answer · 2016-02-05 07:21:45Z

1

You should quote the variables properly

Example

$ awk 'BEGIN{variableToUse="/MainDir/MainDir1/MainDir2/OutputFile_today.xml"; print variableToUse}'
/MainDir/MainDir1/MainDir2/OutputFile_today.xml

To get the current date you can use strftime

Example

$ awk 'BEGIN{today="date +%Y%m%d";variableToUse="/MainDir/MainDir1/MainDir2/OutputFile_"strftime("%Y%m%d")".xml"; print variableToUse}'
/MainDir/MainDir1/MainDir2/OutputFile_20160205.xml

edited Feb 5, 2016 at 7:21

answered Feb 5, 2016 at 6:49

nu11p01n73R

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2 Comments

user2488578 Over a year ago

The above code prints /MainDir/MainDir1/MainDir2/OutputFile_today.xml. But I want, /MainDir/MainDir1/MainDir2/OutputFile_20160205.xml

nu11p01n73R Over a year ago

@user2488578 Sorry for that, I just noticed the error while creating the variable. updated the answer to get the today as required using strftime

anubhava · Accepted Answer · 2016-02-05 07:15:51Z

1

Have your awk script like this:

BEGIN {
   today="date +%Y%m%d";
   variableToUse="/MainDir/MainDir1/MainDir2/OutputFile_" today ".xml"
}

/<record / { i=1 }
i { a[i++]=$0 }
/<\/record>/ {
    if (found) {
         print a[i] >> variableToUse
    }
}

btw there are couple of other issues: - I don't see found getting set anywhere in this script. - today="date +%Y%m%d" will not execute date command. It just assigns literaldate +%Y%m%dtotodayvariable. If you want to executedate` command then use:

awk -v today="$(date '+%Y%m%d')" -f myAWK.awk

and remove today= line from BEGIN block.

edited Feb 5, 2016 at 7:15

answered Feb 5, 2016 at 7:09

anubhava

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