root@netkiller /var/log % yum --showduplicates list httpd | expand
Repository epel is listed more than once in the configuration
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Available Packages
httpd.x86_64                    2.4.6-67.el7.centos                      os
httpd.x86_64                    2.4.6-67.el7.centos.2                    updates
			

root@netkiller /var/log % cat /etc/fstab | unexpand -t 16
/dev/vda1	     /	          ext3	     noatime,acl,user_xattr 1 1
proc	     /proc	          proc	     defaults	           0 0
sysfs	     /sys	          sysfs	     noauto	           0 0
debugfs	     /sys/kernel/debug    debugfs    noauto	           0 0
devpts	     /dev/pts	          devpts     mode=0620,gid=5       0 0
			

将16个空格替换为一个TAB符