write line count to a variable?

tatoosh · 07-30-2009, 07:23 AM

I want to count my postmap duplicates, but didnt get it to work.

here is my shell code. Can u give me an advice ?

Code:

postmap test 2> duplicates.tmp
var_duplicates='wc duplicates.tmp | awk '{print $1}''
echo $var_duplicates " duplicates found"

Agrouf · 07-30-2009, 07:32 AM

var_duplicates=$(wc -l duplicates.tmp)

tatoosh · 07-30-2009, 07:38 AM

great that works. thanks a lot.

now i want to substract to variables.
the last line didnt work. can u help me there, too ?

Code:

var_duplicates=$(wc -l duplicates.tmp | awk '{print $1}')
var_original=(wc -l original.tmp | awk '{print $1}')
var_converted=(wc -l convert3.tmp | awk '{print $1}')

echo "$var_duplicates duplucates found."
echo "removed lines: $var_original-$var_converted"

colucix · 07-30-2009, 07:40 AM

Quote:

Originally Posted by tatoosh

Code:

var_duplicates='wc duplicates.tmp | awk '{print $1}''

The syntax for command substitution is either `command` (with back quotes) or $(command) as in the example by Agrouf

colucix · 07-30-2009, 07:41 AM

Quote:

Originally Posted by Agrouf

var_duplicates=$(wc -l duplicates.tmp)

This returns also the file name. To retrieve only the line count, better to do cat file | wc -l.

tatoosh · 07-30-2009, 07:43 AM

thx colucix.
that's why i used: | awk '{print $1}

it's the same, or?

colucix · 07-30-2009, 07:44 AM

Quote:

Originally Posted by tatoosh

now i want to substract to variables.
the last line didnt work. can u help me there, too ?

Syntax for arithmetic expansion in BASH:

Code:

echo "removed lines: $(($var_original - $var_converted))"

If using the Bourne Shell (or for compatibility with /bin/sh):

Code:

echo "removed lines: `expr $var_original - $var_converted`"

colucix · 07-30-2009, 07:46 AM

Quote:

Originally Posted by tatoosh

thx colucix.
that's why i used: | awk '{print $1}

it's the same, or?

Of course. Using cat or awk implies you use an external command in both cases. The result is exactly the same.

tatoosh · 07-30-2009, 08:01 AM

thx a lot colucix.

my script runs fine now - with your help

Tinkster · 07-30-2009, 03:44 PM

Or, avoiding a second command:

Code:

var_duplicates=$(wc -l < duplicates.tmp)[

Cheers,
Tink