[devtac@test_1 shell]$ vi check_user.sh#! /bin/shecho "You are logged in as `whoami`";if [ `whoami` != devtac ]; then  echo "Must be logged in as devtac to run this script."  exitfiecho "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 devtacRunning 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=necho "Do you really want to continue? (y/n)"read doContinueif [ "$doContinue" != y ]; then   echo "Quitting..."   exitfiecho "OK... we will continue."

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

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

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

DESCRIPTION       Print or change terminal characteristics.

[devtac@test_1 shell]$ stty -aspeed 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 -iutf8opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke

       [-]echo              echo input characters

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

[devtac@test_1 shell]$ ./is_a_directory.sh ERROR : Invalid number of argumentsUsage : ./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" ]; then   echo ""   echo "ERROR : Invalid number of arguments"   echo "Usage : $0 agr1"   echo ""   exitfiif [ ! -r $1 ]; then   echo "$1 is NOT readable."else   echo "$1 is readable."fi~

[devtac@test_1 shell]$ ./is_readable.sh ERROR : Invalid number of argumentsUsage : ./is_readable.sh agr1[devtac@test_1 shell]$ ./is_readable.sh asdfasasdfas 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 ]   do      echo $1      shift   done

[devtac@test_1 shell]$ ./print_args.sh [devtac@test_1 shell]$ ./print_args.sh asdf asdfasd asdfasdfasasdfasdfasdasdfasdfas[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/shelltemp2copying /home/devtac/shell/a.txt to /home/devtac/shelltemp2/a.txtcopying /home/devtac/shell/b.txt to /home/devtac/shelltemp2/b.txtcopying /home/devtac/shell/check_user.sh to /home/devtac/shelltemp2/check_user.shcopying /home/devtac/shell/copy_special_dir_file.sh to /home/devtac/shelltemp2/copy_special_dir_file.shcopying /home/devtac/shell/copy_special_dir_file.sh.bk to /home/devtac/shelltemp2/copy_special_dir_file.sh.bkcopying /home/devtac/shell/do_continue.sh to /home/devtac/shelltemp2/do_continue.shcopying /home/devtac/shell/hide_input.sh to /home/devtac/shelltemp2/hide_input.shcopying /home/devtac/shell/is_a_directory.sh to /home/devtac/shelltemp2/is_a_directory.shcopying /home/devtac/shell/is_readable.sh to /home/devtac/shelltemp2/is_readable.shcopying /home/devtac/shell/print_args.sh to /home/devtac/shelltemp2/print_args.shcopying /home/devtac/shell/sh01.sh to /home/devtac/shelltemp2/sh01.sh[devtac@test_1 shell]$