IPアドレスからホスト名を調べる
#!/bin/sh #ip2host.sh IP_address r_host(){ set -- `host $1` shift `expr $# -1` case $1 in *\(NXDOMAIN\)) return 1 ;; *) expr "$1" : "\(.*\)\." esac } r_nslookup(){ set -- `/usr/sbin/nslookup $1 2>/dev/null | grep '^Name:'` if [ -n "$2" ]; then echo $2 else return 1 fi } case `uname` in SunOS) RESOLVER=r_nslookup ;; *) RESOLVER=r_host esac $RESOLVER $1