[root@VM_64_7_centos tmp]# id
uid=0(root) gid=0(root) groups=0(root)
[root@VM_64_7_centos tmp]# id test
id: test: no such user
[root@VM_64_7_centos tmp]# id root
uid=0(root) gid=0(root) groups=0(root)
[root@VM_64_7_centos tmp]# useradd test
[root@VM_64_7_centos tmp]# id
uid=0(root) gid=0(root) groups=0(root)
[root@VM_64_7_centos tmp]# id test
uid=1000(test) gid=1000(test) groups=1000(test)
[root@VM_64_7_centos tmp]# gpasswd -a test root
Adding user test to group root
[root@VM_64_7_centos tmp]# id test
uid=1000(test) gid=1000(test) groups=1000(test),0(root)
[root@VM_64_7_centos tmp]# gpasswd -d test root
Removing user test from group root
[root@VM_64_7_centos tmp]# id test
uid=1000(test) gid=1000(test) groups=1000(test)
[root@VM_64_7_centos ~]# passwd test
Changing password for user test.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[test@VM_64_7_centos tmp]$ id
uid=1000(test) gid=1000(test) groups=1000(test)
[test@VM_64_7_centos tmp]$ su - root
Password:
[root@VM_64_7_centos tmp]# id
uid=0(root) gid=0(root) groups=0(root)
[root@VM_64_7_centos tmp]#
[root@VM_64_7_centos tmp]# userdel -r test
[root@VM_64_7_centos tmp]# id test
id: test: no such user

[root@VM_64_7_centos tmp]# ls -l
total 8
-r--r--r-- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod g+w o+x ./test.sh
chmod: cannot access 'o+x': No such file or directory
[root@VM_64_7_centos tmp]# chmod g+w ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-r--rw-r-- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod u+wx ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rwxrw-r-- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod o+x ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rwxrw-r-x 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod a-rwx ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
---------- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod u+rwx ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rwx------ 1 root root 616 Dec 18 13:48 test.sh

[root@VM_64_7_centos tmp]# ls -l
total 8
-rwx------ 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 000 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
---------- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod u+001 ./test.sh
chmod: invalid mode: 'u+001'
Try 'chmod --help' for more information.
[root@VM_64_7_centos tmp]# chmod 001 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
---------x 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 020 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-----w---- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 400 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-r-------- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 600 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rw------- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 700 ./test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rwx------ 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# chmod 744 test.sh
[root@VM_64_7_centos tmp]# ls -l
total 8
-rwxr--r-- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]#

[root@VM_64_7_centos tmp]# getfacl test.sh
# file: test.sh
# owner: root
# group: root
user::rwx
group::r-x
other::r-x

[root@VM_64_7_centos tmp]# setfacl -m u:test:rwx test.sh
[root@VM_64_7_centos tmp]# getfacl test.sh
# file: test.sh
# owner: root
# group: root
user::rwx
user:test:rwx
group::r-x
mask::rwx
other::r-x

[root@VM_64_7_centos tmp]# setfacl -x user:test test.sh
[root@VM_64_7_centos tmp]# getfacl test.sh
# file: test.sh
# owner: root
# group: root
user::rwx
group::r-x
mask::r-x
other::r-x

[root@VM_64_7_centos tmp]# ls -l
total 8
-rwxr-xr-x+ 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# setfacl -b test.sh
[root@VM_64_7_centos tmp]# getfacl test.sh
# file: test.sh
# owner: root
# group: root
user::rwx
group::r-x
other::r-x

[root@VM_64_7_centos tmp]#

运行结果：

[root@VM_64_7_centos tmp]# ls -l
total 8
---------- 1 root root 616 Dec 18 13:48 test.sh
[root@VM_64_7_centos tmp]# bash test.sh

current sh file name ./test.sh ./test.sh ./test.sh_file
10470
total value is:4
10 * 20 = 200
a==b or a>0
9
file enable write
file is not empty
0
1
2
a
b
c
array length is 3; array contain element is: a b c
5
6
call count function 10+20=30

[root@VM_64_7_centos tmp]# ./test.sh
-bash: ./test.sh: Permission denied

sheel脚本内容：

#! /bin/bash
echo "current sh file name $0 ${0} $0_file"
echo $$
value=`expr 2 + 2`
echo "total value is:${value}"
a=10
b=20
ab=`expr $a \* $b`
echo "$a * $b = $ab"

#echo "please inputi c:"
#read c
#ab=`expr $a / $c`
#echo "$a/$c=${ab}"

if [ $a == $b -o $a -gt 0 ];
then
echo "a==b or a>0"
else
echo "a!=b"
fi

str="dog,cat,fish,cattle,pig,rabbit"
echo `expr index $str fish`

file="/usr/tmp/file.test"
if [ -e ${file} ]
then
if [ -w $file ]
then
echo "file enable write"
fi
if [ -s $file ]
then
echo "file is not empty"
else
echo "file is empty"
fi
fi

#loop
for ((i=0;i<3;i++))
do echo $i
done

#array=(a b c)
array[0]=a
array[1]=b
array[2]=c
for i in ${array[@]}
do echo $i
done
echo "array length is" ${#array[@]}"; array contain element is:" ${array[@]}

j=5
while [ $j -lt 7 ]
do
echo $j
j=$(($j+1))
done

name=bird
case $name in
dog)
echo $name;;
cat)
echo $name;;
fish)
echo $name;;
rabbit)
echo $name;;
esac

total=0
count(){
total=$(($1+$2))
}

count 10 20
echo "call count function 10+20=$total"

echo ${array[@]} >> /usr/tmp/file.test

<<EOF

read var
echo "You input is $var"
EOF