CODEWITHSUNDEEP
bashawk
hellish
hellish

Reputation: 431

awk How pass parameters to the function, called from inside awk

Sample function:

$ testfn() { echo "${1} world"; }
$ testfn hello
hello world

awk example:

$ echo "something bla bla2"|awk '$1 ~/something/ { print $0; }'
something bla bla2

Now I want to change "something" to "something world" using created above function, when printing it as a whole line, by passing first awk " column element" as a parameter:

$ echo "something bla bla2"|awk '$1 ~/something/ { $1="'"$(testfn) $1"'" ; print $0 }'
 world  bla bla2

^^ Above doesn't work

Is there any way to pass parameters from awk to the function inside awk ?

Upvotes: 0

Views: 4920

Answers (2)

Steve
Steve

Reputation: 54392

No - you can't call shell functions from inside of awk. It's not a shell. However, a common workaround involves adding your function to a file and calling it using awk's system() function. Here's a simple example:

Contents of yourfunction.sh:

{
    echo "$1 world"
}

Then run:

echo "what the ..." | awk '{ system("./yourfunction.sh" FS $1) }'

Results:

what world

Note that if you find yourself having to do this, there's almost certainly a better approach. What are you actually trying to do here?

EDIT:

In response to the comments below, use the getline() function:

echo "what the ..." | awk '{ "./yourfunction.sh" FS $1 | getline $1 }1'

Results:

what world the ...

Here's some info re the getline() function:

http://www.gnu.org/software/gawk/manual/html_node/Getline.html

Upvotes: 1

Ed Morton
Ed Morton

Reputation: 203324

Highly unrecommended but:

$ cat .env
testfn() { echo "${1} world"; }
$ echo $BASH_ENV
.env
$ echo "something bla bla2" | awk '$1 ~/something/{"bash -c \"testfn " $1 "\"" | getline $1; print $0}'
something world bla bla2

Now, tell us what you're really trying to do and we can help you write a sane script to do that.

Upvotes: 2

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