[root@template ~]# history
    1  ifconfig
    2  vim /etc/ssh/sshd_config 
    3  /etc/init.d/sshd restart
    4  vim /boot/grub/grub.conf 
    5  vim /etc/selinux/config 
    6  vim /etc/sysconfig/network-scripts/ifcfg-eth0
    7  rm -rf /etc/udev/rules.d/70-persistent-net.rules 
    8  useradd vsroot
    9  echo -e ‘vsroot\tALL=(ALL)\tNOPASSWD: ALL‘ >> /etc/sudoers
   10  yum clean all
   11  rm -rf /var/log/yum.log 
   12  rm -rf /var/lib/yum/*
   13  rm -rf /root/install.log
   14  rm -rf /root/install.log.syslog 
   15  rm -rf /var/log/anaconda.*

[root@CentOS ~]# cat /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It‘s NOT a good idea to change this file unless you know what you
# are doing. It‘s much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

pathmunge () {
    case ":${PATH}:" in
        *:"$1":*)
            ;;
        *)
            if [ "$2" = "after" ] ; then
                PATH=$PATH:$1
            else
                PATH=$1:$PATH
            fi
    esac
}


if [ -x /usr/bin/id ]; then
    if [ -z "$EUID" ]; then
        # ksh workaround
        EUID=`id -u`
        UID=`id -ru`
    fi
    USER="`id -un`"
    LOGNAME=$USER
    MAIL="/var/spool/mail/$USER"
fi

# Path manipulation
if [ "$EUID" = "0" ]; then
    pathmunge /sbin
    pathmunge /usr/sbin
    pathmunge /usr/local/sbin
else
    pathmunge /usr/local/sbin after
    pathmunge /usr/sbin after
    pathmunge /sbin after
fi

HOSTNAME=`/bin/hostname 2>/dev/null`
HISTSIZE=1000
if [ "$HISTCONTROL" = "ignorespace" ] ; then
    export HISTCONTROL=ignoreboth
else
    export HISTCONTROL=ignoredups
fi

export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL

# By default, we want umask to get set. This sets it for login shell
# Current threshold for system reserved uid/gids is 200
# You could check uidgid reservation validity in
# /usr/share/doc/setup-*/uidgid file
if [ $UID -gt 199 ] && [ "`id -gn`" = "`id -un`" ]; then
    umask 002
else
    umask 022
fi

for i in /etc/profile.d/*.sh ; do
    if [ -r "$i" ]; then
        if [ "${-#*i}" != "$-" ]; then
            . "$i"
        else
            . "$i" >/dev/null 2>&1
        fi
    fi
done

unset i
unset -f pathmunge
[root@CentOS ~]#