perl 从指定行插入字符

zjzc01:/root/big2# cat a27.pl 
$curip="$ARGV[0]";
$str='export CATALINA_OPTS="$CATALINA_OPTS -Djava.rmi.server.hostname=$curip -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=10053 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false';
$str =~ s/$curip/$curip/g;
open( C, "<", "pp.txt" ) || die "$!
";
    while (<C>) {
chomp $_;
    if  ($. == 2 ){
     print "$str
";
     print "$_
";
    
            }
else {print "$_
";}
         }
zjzc01:/root/big2# perl a27.pl  2.2.2.2
a
export CATALINA_OPTS="$CATALINA_OPTS -Djava.rmi.server.hostname=2.2.2.2 -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=10053 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false
b
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