Strange exit of while loop Post: 302537222

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Top Forums Shell Programming and Scripting Strange exit of while loop Post 302537222 by trimike on Thursday 7th of July 2011 12:07:44 PM

07-07-2011

Registered User

Strange exit of while loop

This code is used to check for duplicate ip and hostnames in an /etc/hosts file

CENTRAL is path to /etc/hosts
AWK =awk

Code:

 #check CENTRAL for duplicate ips or hostnames#
        grep -v "^#" $CENTRAL | $AWK '{ print $1, $2; }' | \
        while read ip hostname
        do
                if [ "$ip" != "" -a "$hostname" != "" ]
                then
                echo $ip $hostname
                        ret=`grep -v "^#" | grep -w "$ip" $CENTRAL | wc -l`
                        ret1=`grep -v "^#" | grep -w "$hostname" $CENTRAL | wc -l`
                        if [[ $ret > 1 ]]
                        then
                                echo "$ME:Duplicate IP in hosts.central: $ip $hostname"
                                error=true
                        elif [[ $ret1 > 1 ]]
                        then
                                echo "$ME:Duplicate hostname in hosts.central:$ip $hostname"
                                error=true
                        fi
                fi
        done

The result from this code is that it only iterates through 1 line

output:
127.0.0.1 localhost

strange enough when I comment out

Code:

ret=`grep -v "^#" | grep -w "$ip" $CENTRAL | wc -l`
ret1=`grep -v "^#" | grep -w "$hostname" $CENTRAL | wc -l`

it gives me my intended ouput

127.0.0.1 localhost
192.168.2.1 myip
192.168.2.3 myip

Note the $CENTRAL file contains the following entries

127.0.0.1 localhost
192.168.2.1 myip
192.168.2.3 myip

Any thoughts Smilie

Thanks

---------- Post updated at 11:07 AM ---------- Previous update was at 10:55 AM ----------

I believe I just found my issue..
my grep form is off..

Code:

ret=`grep -v "^#" $CENTRAL  | grep -w "$ip"  | wc -l`
ret1=`grep -v "^#" $CENTRAL  | grep -w "$hostname" | wc -l`

trimike

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LEARN ABOUT SUSE

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)

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