Memory leak with awk on MacOs Post: 302984653

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Top Forums UNIX for Beginners Questions & Answers Memory leak with awk on MacOs Post 302984653 by comm|getline on Friday 28th of October 2016 08:42:14 PM

10-28-2016

Registered User

Memory leak with awk on MacOs

Dear all,

I use awk quite a bit for data wrangling ... today I find weird behavior that I cannot wrap my head around.

if I execute the following command (simplified to illustrate the behavior ... nothing to do with the real command)

Code:

bash-3.2$ awk 'BEGIN{for(i=1;i<=100000000;i++){for(j=1;j<=10;j++){s="a";}}}'

things are fine. I have relative constant memory usage (a couple of K). If I modify it slightly to

Code:

bash-3.2$ awk 'BEGIN{for(i=1;i<=100000000;i++){for(j=1;j<=10;j++){s="a"j;}}}'

I can watch this command starting to take gigabytes of memory (I am looking at it using "top").

It seems concatening a string and the number j causes problems, although in principle I store only one variable at any point in time. I am pretty sure that this never happened before. This is happening on MacOS.

If anyone has seen this, please do let me know what to do!

Last edited by jim mcnamara; 10-28-2016 at 09:49 PM..

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igawk

IGAWK(1)							 Utility Commands							  IGAWK(1)

NAME

       igawk - gawk with include files

SYNOPSIS

       igawk [ all gawk options ] -f program-file [ -- ] file ...
       igawk [ all gawk options ] [ -- ] program-text file ...

DESCRIPTION

       Igawk is a simple shell script that adds the ability to have ``include files'' to gawk(1).

       AWK programs for igawk are the same as for gawk, except that, in addition, you may have lines like

	      @include getopt.awk

       in your program to include the file getopt.awk from either the current directory or one of the other directories in the search path.

OPTIONS

       See gawk(1) for a full description of the AWK language and the options that gawk supports.

EXAMPLES

       cat << EOF > test.awk
       @include getopt.awk

       BEGIN {
	    while (getopt(ARGC, ARGV, "am:q") != -1)
		 ...
       }
       EOF

       igawk -f test.awk

SEE ALSO

       gawk(1)

       Effective AWK Programming, Edition 1.0, published by the Free Software Foundation, 1995.

AUTHOR

       Arnold Robbins (arnold@skeeve.com).

Free Software Foundation					    Nov 3 1999								  IGAWK(1)