sed和grep操作

jrhapt01:/usr/local/apache-tomcat-7.0.55_8081/logs> grep -n '^2015-05-14' catalina.out | head -1
821734:2015-05-14 00:19:05,935  INFO o.a.shiro.session.mgt.AbstractValidatingSessionManager - Validating all active 

sessions...
jrhapt01:/usr/local/apache-tomcat-7.0.55_8081/logs> sed -n '821734,$' catalina.out  >1
sed: -e expression #1, char 8: missing command
jrhapt01:/usr/local/apache-tomcat-7.0.55_8081/logs> sed -n '821734,$'p catalina.out  >1