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Passing command line arguments to awk

ianfoster
ianfoster asked
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Last Modified: 2013-12-26
How can I pass a command line argument such as $1 or $2 into an awk script?

I have written a shell script that includes some awk programming and i need to be able to call that program by typing ./program inputword and then search for inputword within awk.

For example, if I had a datafile with the following contents:

a:b:c:d:e:f:g:
g:f:e:d:c:b:a:

and i wanted to write a script to search through that file for a name that I give at the command line

awk '
$4 ~ /b/ {print $4} ' datafile

i would like to do it like this

awk '
$4 ~ /input from command line such as $1/ {print $4}' datafile

I have tried this:

awk '
$4 ~ /inputword/ {print $4}' inputword=$1 datafile

without any luck

I have to be able to run the program without having to type something like

awk -f scriptfile datafile

as it gets to confusing.

Can anyone help?


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(echo SPECIAL_VALUE inputword; cat datafile) | awk '/^SPECIAL_VALUE/ { pattern=$2;} $4 ~ pattern {print $4}'
ozo
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Most Valuable Expert 2014
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Commented:
awk "\$4 ~ /$1/ {print \$4}"  datafile

Author

Commented:
I've installed gawk on the machine but still no luck :(


Here's another example:


--------------------

#!/bin/sh

echo "Here we go!"

# the rest of the shell script goes here


gawk -v input=$1 -F: '
$1 ~ /input/ {print $1}' datafile

--------------------


datafile contents as follows

a:b:c:d:
a:b:c:d:
a:b:c:d:

I call the program as follows

/gawkprog a

it should print out "a" for each line but I get nothing.

it does read in the $1 part because I can do this                  

gawk -v input=$1 -F: '
{print input} ' datafile

and run it ./gawkprog a

and it will print out

a
a
a

so the problem seems to be that gawk doesnt like matching things with
the input part.

any ideas?
gawk -v input=$1 -F: '$1 ~ input {print $1}' datafile

BTW, ozo's solution works also inside a shell script
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