#!/bin/bash 
read -p "Enter a number or string here:" input 
 
case $input in 
   [0-9]) echo -e "Good job, Your input is a numberic! \n" ;; 
[a-zA-Z]) echo -e "Good job, Your input is a character! \n" ;; 
       *) echo -e "Your input is wrong, input again!   \n"  ;; 
esac 

#!/bin/bash 
 
# Calculate the average of a series of numbers. 
 
SCORE="0" 
AVERAGE="0" 
SUM="0" 
NUM="0" 
 
while true; do 
 
  echo -n "Enter your score [0-100%] ('q' for quit): "; read SCORE; 
 
  if (("$SCORE" "0"))  || (("$SCORE" > "100")); then 
    echo "Be serious.  Common, try again: " 
  elif [ "$SCORE" == "q" ]; then 
    echo "Average rating: $AVERAGE%." 
    break 
  else 
    SUM=$[$SUM + $SCORE] 
    NUM=$[$NUM + 1] 
    AVERAGE=$[$SUM / $NUM] 
  fi 
 
done 
 
echo "Exiting." 

[scriptname: doit.sh] 
while (( $# > 0 )) 
do 
  echo $* 
  shift 
done  
         
/> ./doit.sh a b c d e 
a b c d e 
b c d e 
c d e 
d e 
e 

# 人名列表 
# cat namelist 
Jame 
Bob 
Tom 
Jerry 
Sherry 
Alice 
John 
 
# 脚本程序 
# cat namelist.sh 
#!/bin/bash 
for name in $(cat namelist) 
do 
        echo "name= " $name 
done 
echo "The name is out of namelist file" 
 
# 输出结果 
# ./namelist.sh 
name=  Jame 
name=  Bob 
name=  Tom 
name=  Jerry 
name=  Sherry 
name=  Alice 
name=  John 

[root@host ~]# cat testfile.sh       
#!/bin/bash 
 
 
for file in test*.sh 
do 
  if [ -f $file ];then 
     echo "$file existed." 
  fi 
done 
 
[root@host ~]# ./testfile.sh 
test.sh existed. 
test1.sh existed. 
test2.sh existed. 
test3.sh existed. 
test4.sh existed. 
test5.sh existed. 
test78.sh existed. 
test_dev_null.sh existed. 
testfile.sh existed. 

[root@host ~]# df -ih /tmp 
Filesystem            Inodes   IUsed   IFree IUse% Mounted on 
/dev/mapper/vg00-lvol5 
                       1000K    3.8K    997K    1% /tmp 
[root@host ~]# cat cover_disk.sh 
#!/bin/env bash 
counter=0 
max=3800 
remainder=0 
while true 
do 
    ((counter=counter+1)) 
    if [ ${#counter} -gt $max ];then 
        break 
    fi 
    ((remainder=counter%1000)) 
    if [ $remainder -eq 0 ];then 
        echo -e "counter=$counter\tdate=" $(date) 
    fi 
    mkdir -p /tmp/temp 
    cat testfile > "/tmp/temp/myfile.$counter" 
    if [ $? -ne 0 ];then 
        echo "Failed to write file to Disk." 
        exit 1 
    fi 
done 
echo "Done!" 
[root@host ~]# ./cover_disk.sh 
counter=1000    date= Wed Sep 10 09:20:39 HKT 2014 
counter=2000    date= Wed Sep 10 09:20:48 HKT 2014 
counter=3000    date= Wed Sep 10 09:20:56 HKT 2014 
cat: write error: No space left on device 
Failed to write file to Disk. 
dd if=/dev/zero of=testfile bs=1M count=1 

[root@host ~]# cat hosts.allow 
127.0.0.1 
127.0.0.2 
127.0.0.3 
127.0.0.4 
127.0.0.5 
127.0.0.6 
127.0.0.7 
127.0.0.8 
127.0.0.9 
[root@host ~]# cat readlines.sh 
#!/bin/env bash 
i=0 
while read LINE;do 
    hosts_allow[$i]=$LINE 
    ((i++)) 
done hosts.allow 
for ((i=1;i=${#hosts_allow[@]};i++)); do 
    echo ${hosts_allow[$i]} 
done 
echo "Done" 
[root@host ~]# ./readlines.sh 
127.0.0.2 
127.0.0.3 
127.0.0.4 
127.0.0.5 
127.0.0.6 
127.0.0.7 
127.0.0.8 
127.0.0.9 
Done 

[root@host ~]# cat regex.sh 
#!/bin/env sh 
#Filename: regex.sh 
regex="[A-Za-z0-9]{6}" 
if [[ $1 =~ $regex ]] 
then 
  num=$1 
  echo $num 
else 
  echo "Invalid entry" 
  exit 1 
fi 
[root@host ~]# ./regex.sh 123abc 
123abc 
 
#!/bin/env bash 
#Filename: validint.sh 
validint(){ 
    ret=`echo $1 | awk '{start = match($1,/^-?[0-9]+$/);if (start == 0) print "1";else print "0"}'` 
    return $ret 
} 
 
validint $1 
 
if [ $? -ne 0 ]; then 
    echo "Wrong Entry" 
    exit 1 
else 
    echo "OK! Input number is:" $1 
fi 

#!/bin/bash 
 
NOW=$(date +"%m-%d-%Y")      # 当前日期 
FILE="backup.$NOW.tar.gz"    # 备份文件 
echo "Backing up data to /tmp/backup.$NOW.tar.gz file, please wait..."  #打印信息 
tar xcvf /tmp/backup.$NOW.tar.gz /home/ /etc/ /var       # 同时备份多个文件到指定的tar压缩文件中 
echo "Done..."