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Full Discussion: Please help on AWK
Top Forums Shell Programming and Scripting Please help on AWK Post 302551390 by wabard on Tuesday 30th of August 2011 08:21:33 AM
Old 08-30-2011
Alternate solutions similar to your original method...

Code:
cat test.txt | awk 'BEGIN { v=$NUM } {print ($NF - v ) } '

The BEGIN section is executed prior to the main body of code. Here we load the shell variable into a local variable for use in the print statement.


Code:
cat test.txt | awk '{print ($NF - "$NUM" ) } '

The "quotes" protect the variable name from being part of the sub-shell and passes the parent shell information down


The reason why your original code does not work is that awk runs in a sub-shell to the parent with no variables being passed down (don't remember why the BEGIN statement works though... I'll have to research that). Someone please correct me if I'm wrong, but that's sorta the way I remember it (geez I'm getting old... memory is fading!)
 

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GONZUI-SEARCH(1)						   User Commands						  GONZUI-SEARCH(1)

NAME
gonzui-search - a tool to search a gonzui DB SYNOPSIS
gonzui-search PATTERN DESCRIPTION
-P, --package=PACKAGE search for PACKAGE -p, --prefix perform prefix search -e, --regexp perform regular expression search -t, --type=TYPE search for TYPE funcall, fundef, fundecl, others -n, --line-number print line number with output lines -c, --count only print a count of matching words -C, --context=NUM print NUM lines of output context --color use markers to highlight the matching string -h, --no-filename suppress the prefixing filename on output --gonzuirc=FILE specify alternate run control file --dump-config dump configuration -d, --db-dir=DIR use DB directory DIR --db-cache=NUM use NUM megabytes of DB cache [5] --list-formats list all supported formats --help show this help message -q, --quiet suppress all normal output -v, --verbose output progress and statistics --version print version information and exit gonzui-search 1.3 December 2006 GONZUI-SEARCH(1)
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