🚀 go-pugleaf

In article <tk0qf9s@sgi.sgi.com> arc@xingping.esd.sgi.com (Andrew Cherenson) writes:
>>
>>That is, you don't need the shell-game to reverse the address and add
>>"in-addr.arpa".
>
>nslookup takes command-line options. For example,
>

some do, some don't. This is what I use now (I fancied up the other
script to use as an example sh script for our users)...


#!/bin/sh  

# if you want this to run under ultrix change to "#!/bin/sh5" (bleechh...)

###################### VARIABLES
TRUE=0
FALSE=1
VERBOSE=$FALSE

###################### ROUTINES
		     # remember to pass all arguments
lookit_up() {		
	revaddr=`echo $1 | awk -F. '{printf("%s.%s.%s.%s\n",$4,$3,$2,$1)}'  `
        nslookup <<%% | grep ${revaddr}.in-addr.arpa | awk '{print $NF}'
        set query=ptr
        ${revaddr}.in-addr.arpa
%%
}

print_hostname() {
    if test $VERBOSE -eq $TRUE
    then
	echo $1 = `lookit_up $1 `
    else
	lookit_up $1
    fi
}

printusage() {				# $0 is still the script name...
cat <<%%  

    usage: 	$0 [ -v ] [address...]

    $0 looks up a hostname for each address specified,
    or with no arguments, reads standard input for addresses until EOF.

        -v    Display result as "address = hostname"
%%
}

main() {				# this is here cuz sh doesn't "goto"
if test "$#" -eq 0 			# input is stdin	
then
    while read i
    do
	print_hostname $i
    done
else					# cmd line args...
    case "$1" in
	-h)
	    printusage >&2		# to stderr
	    exit
	    ;;
	-v)
            VERBOSE=$TRUE
            shift
	    main $*			# we'd like "goto" here...
	    exit 
            ;;
	 *)
	    ;;
	
    esac

    while test $# -ge 1
    do
	print_hostname $1
	shift
    done
fi
}

### do the work

main $*

		# There are a number of ways achieving the result of the
		# recursion, however I'd prefer the non-exisitent "goto",
		# so recursion seems the suitably perverse alternative.
-- 
_/**/Sam_Fulcomer	sgf@cfm.brown.edu	What, me panic: uba crazy
Brown University  Center for Fluid Mechanics, Turbulence  and Computation