linux os points need pay attention!

1,mulit line Commented

<< any words

contents

any words

2,append content to the file

cat << EOF >> file path

content

EOF

3,os system env variable path

/etc/profile

PATH=$PATH:/usr/local/webserver/php/bin:/usr/local/webserver/mysql/bin
export PATH

make valid source /etc/profiel

check echo $PATH