[devtac@test_1 shell]$ vi check_user.sh#! /bin/shecho "You are logged in as `whoami`";if [ `whoami` != devtac ]; thenecho "Must be logged in as devtac to run this script."exit
fiecho "Running script at `date`"

[devtac@test_1 shell]$ chmod a+x check_user.sh
[devtac@test_1 shell]$ ./check_user.sh
You are logged in as devtac
Running script at 2014年 12月 09日 星期二 13:35:17 CST

[devtac@test_1 shell]$ vi do_continue.sh#! /bin/shdoContinue=n
echo "Do you really want to continue? (y/n)"
read doContinueif [ "$doContinue" != y ]; thenecho "Quitting..."exit
fiecho "OK... we will continue."

[devtac@test_1 shell]$ ./do_continue.sh
Do you really want to continue? (y/n)
y
OK... we will continue.
[devtac@test_1 shell]$ ./do_continue.sh
Do you really want to continue? (y/n)
n
Quitting...
[devtac@test_1 shell]$ 

[devtac@test_1 shell]$ vi hide_input.sh#! /bin/shstty -echo
echo -n "Enter the database system password:"
read pw
stty echoecho "$pw was entered"

 ./hide_input.sh
Enter the database system password:123qweasd was entered
[devtac@test_1 shell]$ 

DESCRIPTIONPrint or change terminal characteristics.

[devtac@test_1 shell]$ stty -a
speed 38400 baud; rows 47; columns 125; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S;
susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 -hupcl -cstopb cread -clocal -crtscts -cdtrdsr
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke

       [-]echoecho input characters

[devtac@test_1 shell]$ vi is_a_directory.sh #! /bin/shif [ -z "$1" ]; thenecho ""echo "ERROR : Invalid number of arguments"echo "Usage : $0 arg1"echo ""exit
fiif [ -d $1 ]; thenecho "$1 is a directory."
elseecho "$1 is not a directory."
fi

[devtac@test_1 shell]$ ./is_a_directory.sh ERROR : Invalid number of arguments
Usage : ./is_a_directory.sh arg1[devtac@test_1 shell]$ ./is_a_directory.sh $PWD
/home/devtac/shell is a directory.

[devtac@test_1 shell]$ vi is_readable.sh#! /bin/shif [ -z "$1" ]; thenecho ""echo "ERROR : Invalid number of arguments"echo "Usage : $0 agr1"echo ""exit
fiif [ ! -r $1 ]; thenecho "$1 is NOT readable."
elseecho "$1 is readable."
fi
~

[devtac@test_1 shell]$ ./is_readable.sh ERROR : Invalid number of arguments
Usage : ./is_readable.sh agr1[devtac@test_1 shell]$ ./is_readable.sh asdfas
asdfas is NOT readable.
[devtac@test_1 shell]$ ./is_readable.sh $PWD
/home/devtac/shell is readable.
[devtac@test_1 shell]$ ./is_readable.sh /home/devtac/
/home/devtac/ is readable.
[devtac@test_1 shell]$ ./is_readable.sh /home/devtac/shell/is_readable.sh
/home/devtac/shell/is_readable.sh is readable.

[devtac@test_1 shell]$ vi print_args.sh#! /bin/shwhile [ $# -ne 0 ]doecho $1shiftdone

[devtac@test_1 shell]$ ./print_args.sh
[devtac@test_1 shell]$ ./print_args.sh asdf asdfasd asdfasdfas
asdf
asdfasd
asdfasdfas
[devtac@test_1 shell]$ 

[devtac@test_1 shelltemp2]$ vi copy_special_dir_file.sh

#! /bin/sh

#echo $#
# if the number of args is not equal 2 ,output command usage and exit
if [ $# -ne 2 ];then
echo "Usage : $0 fromdir todir"
exit 1
fi

fromdir=$1 #from directory
todir=$2 #to directory
#echo $fromdir $todir

#if fromdir or todir is not a valid directory ,exit
if [ ! -d $fromdir ] || [ ! -d $todir ];then
echo $fromdir or $todir is not a valid directory
exit 1
fi

for i in $fromdir/*; do
if [ -f $i ]; then
filename=${i#$fromdir/}
echo copying $i to $todir/$filename
cp -p $i $todir/$filename
fi
done
exit 0

[devtac@test_1 shell]$ ./copy_special_dir_file.sh /home/devtac/shell /home/devtac/shelltemp2/qewqe
/home/devtac/shell or /home/devtac/shelltemp2/qewqe is not a valid directory
[devtac@test_1 shell]$ rm ../shelltemp2/*
[devtac@test_1 shell]$ ./copy_special_dir_file.sh /home/devtac/shell /home/devtac/shelltemp2
copying /home/devtac/shell/a.txt to /home/devtac/shelltemp2/a.txt
copying /home/devtac/shell/b.txt to /home/devtac/shelltemp2/b.txt
copying /home/devtac/shell/check_user.sh to /home/devtac/shelltemp2/check_user.sh
copying /home/devtac/shell/copy_special_dir_file.sh to /home/devtac/shelltemp2/copy_special_dir_file.sh
copying /home/devtac/shell/copy_special_dir_file.sh.bk to /home/devtac/shelltemp2/copy_special_dir_file.sh.bk
copying /home/devtac/shell/do_continue.sh to /home/devtac/shelltemp2/do_continue.sh
copying /home/devtac/shell/hide_input.sh to /home/devtac/shelltemp2/hide_input.sh
copying /home/devtac/shell/is_a_directory.sh to /home/devtac/shelltemp2/is_a_directory.sh
copying /home/devtac/shell/is_readable.sh to /home/devtac/shelltemp2/is_readable.sh
copying /home/devtac/shell/print_args.sh to /home/devtac/shelltemp2/print_args.sh
copying /home/devtac/shell/sh01.sh to /home/devtac/shelltemp2/sh01.sh
[devtac@test_1 shell]$