；举例
[root@andon ~]# date;dd if=/dev/zero of=/home/1 bs=1k count=10240;date ##统计dd命令消耗时间，其中/dev/zero为空文件 Tue Jun 14 15:15:02 CST 2016 10240+0 records in 10240+0 records out 10485760 bytes (10 MB) copied, 0.0224696 s, 467 MB/s Tue Jun 14 15:15:02 CST 2016
&&举例
[root@andon ~]# ls &&echo yes 1 anaconda-ks.cfg install.log install.log.syslog shell yes [root@andon ~]# lss &&echo yes -bash: lss: command not found
||举例
[root@andon ~]# ls || echo yes 1 anaconda-ks.cfg install.log install.log.syslog shell [root@andon ~]# lsd || echo yes -bash: lsd: command not found yes
管道“|”
