[SOLVED] Passing a variable to AWK

mhicky05 · 12-09-2013, 11:46 PM

Hello Experts,

I am newbie in UNIX shell scripting. I am more of an application administrator but I find shell scripting very good specially for automation of some stuff. I hope my question is valid.

I am having trouble with AWK command, I never thought this 3 letter command will have that complexity.

My logic is to pass a variable as an FNR value in awk

Code:

#!/usr/bin/sh
       
cFile1=`wc -l ${File1}|awk '{print$1}'`

echo "`awk -v m=${cFile1} 'FNR == m {print $1}' ${FILE1}`"

However, the "echo" part of the code seems not working. Is there anyone who can help me on this?

Thank you so much in advance! :-)

pan64 · 12-10-2013, 12:40 AM

what does it really mean:
echo "`awk command`"
you could simply write
awk command.

colucix · 12-10-2013, 01:49 AM

The main problem in your code is that you reference FILE1 instead of File1 in the echo/awk statement. Provided this is the main caveat, it looks like you want to extract the first field from the last line of a file, so why not simply do something like this?

Code:

#!/usr/bin/sh
awk 'END{print $1}'

SAbhi · 12-10-2013, 02:04 AM

@colucix and @pan_64 have already posted the relevant info so for further needs, try telling us what you are trying to achieve with this ?

mhicky05 · 12-10-2013, 04:02 AM

Hi Colucix,

Very great! That is the culprit! BTW, thank you for your suggestion RE: my syntax.

This is just part of my logic. The real program should be able to check a string from FILE1 to FILE2 and compare if they have the same values. If not, then it will state which line of the text the string is located. I need to do this to automate the checking of the parameters of our application.

I didn't put the whole program because someone might say that I'm asking to do my homework :-).

Thanks to other contributors as well. Happy holidays!

SAbhi · 12-10-2013, 07:03 PM

Quote:

Originally Posted by mhicky05

Hi Colucix,

I didn't put the whole program because someone might say that I'm asking to do my homework :-).

Thanks to other contributors as well. Happy holidays!

Well it would be great if you have shared what you tried till now, anyhow we will be asking for it !! :P we will not do your homework but we can help suggesting best way to achieve your task out of what you tried.