shell教程

$ echo '#!/bin/sh' > my-script.sh
$ echo 'echo Hello World' >> my-script.sh
$ chmod 755 my-script.sh
$ ./my-script.sh
Hello World
$

#!/bin/sh
# This is a comment!
echo Hello World	# This is a comment, too!

$ chmod a+rx my-script.sh
$ ./my-script.sh

grep "mystring" /tmp/myfile

#!/bin/sh
# This is a comment!
echo Hello World        # This is a comment, too!

$ chmod 755 first.sh
$ ./first.sh
Hello World
$

$ echo Hello World
Hello World
$

#!/bin/sh
MY_MESSAGE="Hello World"
echo $MY_MESSAGE

$ export name=zuoyuan

#!/bin/sh
echo What is your name?
read MY_NAME
echo "Hello $MY_NAME - hope you're well."

#!/bin/sh
echo "What is your name?"
read USER_NAME
echo "Hello $USER_NAME"
echo "I will create you a file called ${USER_NAME}_file"
touch "${USER_NAME}_file"

#!/bin/sh
for i in 1 2 3 4 5
do
  echo "Looping ... number $i"
done

#!/bin/sh
for i in hello 1 * 2 goodbye
do
  echo "Looping ... i is set to $i"
done

#!/bin/sh
INPUT_STRING=hello
while [ "$INPUT_STRING" != "bye" ]
do
  echo "Please type something in (bye to quit)"
  read INPUT_STRING
  echo "You typed: $INPUT_STRING"
done

#!/bin/sh
while :
do
  echo "Please type something in (^C to quit)"
  read INPUT_STRING
  echo "You typed: $INPUT_STRING"
done

#!/bin/sh
while read f
do
  case $f in
	hello)		echo English	;;
	howdy)		echo American	;;
	gday)		echo Australian	;;
	bonjour)	echo French	;;
	"guten tag")	echo German	;;
	*)		echo Unknown Language: $f
		;;
   esac
done < myfile

for runlevel in 0 1 2 3 4 5 6 S
do
  mkdir rc${runlevel}.d
done

if [ ... ]
then
  # if-code
else
  # else-code
fi

if [ ... ]; then
  # do something
fi

if  [ something ]; then
 echo "Something"
 elif [ something_else ]; then
   echo "Something else"
 else
   echo "None of the above"
fi

#!/bin/sh
if [ "$X" -lt "0" ]
then
  echo "X is less than zero"
fi
if [ "$X" -gt "0" ]; then
  echo "X is more than zero"
fi
[ "$X" -le "0" ] && 
      echo "X is less than or equal to  zero"
[ "$X" -ge "0" ] && 
      echo "X is more than or equal to zero"
[ "$X" = "0" ] && 
      echo "X is the string or number "0""
[ "$X" = "hello" ] && 
      echo "X matches the string "hello""
[ "$X" != "hello" ] && 
      echo "X is not the string "hello""
[ -n "$X" ] && 
      echo "X is of nonzero length"
[ -f "$X" ] && 
      echo "X is the path of a real file" || 
      echo "No such file: $X"
[ -x "$X" ] && 
      echo "X is the path of an executable file"
[ "$X" -nt "/etc/passwd" ] && 
      echo "X is a file which is newer than /etc/passwd"

echo -en "Please guess the magic number: "
read X
echo $X | grep "[^0-9]" > /dev/null 2>&1
if [ "$?" -eq "0" ]; then
  # If the grep found something other than 0-9
  # then it's not an integer.
  echo "Sorry, wanted a number"
else
  # The grep found only 0-9, so it's an integer. 
  # We can safely do a test on it.
  if [ "$X" -eq "7" ]; then
    echo "You entered the magic number!"
  fi
fi

#!/bin/sh
X=0
while [ -n "$X" ]
do
  echo "Enter some text (RETURN to quit)"
  read X
  echo "You said: $X"
done

#!/bin/sh
X=0
while [ -n "$X" ]
do
  echo "Enter some text (RETURN to quit)"
  read X
  if [ -n "$X" ]; then
    echo "You said: $X"
  fi
done

if [ "$X" -lt "0" ]
then
  echo "X is less than zero"
fi

..........  and  ........

if [ ! -n "$X" ]; then
  echo "You said: $X"
fi

#!/bin/sh

echo "Please talk to me ..."
while :
do
  read INPUT_STRING
  case $INPUT_STRING in
	hello)
		echo "Hello yourself!"
		;;
	bye)
		echo "See you again!"
		break
		;;
	*)
		echo "Sorry, I don't understand"
		;;
  esac
done
echo 
echo "That's all folks!"

$ ./talk.sh
Please talk to me ...
hello
Hello yourself!
What do you think of politics?
Sorry, I don't understand
bye
See you again!

That's all folks!
$

#!/bin/sh
echo "I was called with $# parameters"
echo "My name is $0"
echo "My first parameter is $1"
echo "My second parameter is $2"
echo "All parameters are $@"

$ /home/steve/var3.sh
I was called with 0 parameters
My name is /home/steve/var3.sh
My first parameter is
My second parameter is    
All parameters are 
$
$ ./var3.sh hello world earth
I was called with 3 parameters
My name is ./var3.sh
My first parameter is hello
My second parameter is world
All parameters are hello world earth

#!/bin/sh
while [ "$#" -gt "0" ]
do
  echo "$1 is $1"
  shift
done

#!/bin/sh
/usr/local/bin/my-command
if [ "$?" -ne "0" ]; then
  echo "Sorry, we had a problem there!"
fi

#!/bin/sh
old_IFS="$IFS"
IFS=:
echo "Please input some data separated by colons ..."
read x y z
IFS=$old_IFS
echo "x is $x y is $y z is $z"

$ ./ifs.sh
Please input some data separated by colons ...
hello:how are you:today
x is hello y is how are you z is today

$ ./ifs.sh
Please input some data separated by colons ...
hello:how are you:today:my:friend
x is hello y is how are you z is today:my:friend

#!/bin/sh
echo -en "What is your name [ `whoami` ] "
read myname
if [ -z "$myname" ]; then
  myname=`whoami`
fi
echo "Your name is : $myname"

#!/bin/sh
# A simple script with a function...

add_a_user()
{
  USER=$1
  PASSWORD=$2
  shift; shift;
  # Having shifted twice, the rest is now comments ...
  COMMENTS=$@
  echo "Adding user $USER ..."
  echo useradd -c "$COMMENTS" $USER
  echo passwd $USER $PASSWORD
  echo "Added user $USER ($COMMENTS) with pass $PASSWORD"
}

###
# Main body of script starts here
###
echo "Start of script..."
add_a_user bob letmein Bob Holness the presenter
add_a_user fred badpassword Fred Durst the singer
add_a_user bilko worsepassword Sgt. Bilko the role model
echo "End of script..."

#!/bin/sh

factorial()
{
  if [ "$1" -gt "1" ]; then
    i=`expr $1 - 1`
    j=`factorial $i`
    k=`expr $1 * $j`
    echo $k
  else
    echo 1
  fi
}


while :
do
  echo "Enter a number:"
  read x
  factorial $x
done 

# common.lib
# Note no #!/bin/sh as this should not spawn 
# an extra shell. It's not the end of the world 
# to have one, but clearer not to.
#
STD_MSG="About to rename some files..."

rename()
{
  # expects to be called as: rename .txt .bak 
  FROM=$1
  TO=$2

  for i in *$FROM
  do
    j=`basename $i $FROM`
    mv $i ${j}$TO
  done
}

#!/bin/sh
# function2.sh
. ./common.lib
echo $STD_MSG
rename .txt .bak

#!/bin/sh

adduser()
{
  USER=$1
  PASSWORD=$2
  shift ; shift
  COMMENTS=$@
  useradd -c "${COMMENTS}" $USER
  if [ "$?" -ne "0" ]; then
    echo "Useradd failed"
    return 1
  fi
  passwd $USER $PASSWORD
  if [ "$?" -ne "0" ]; then
    echo "Setting password failed"
    return 2
  fi
  echo "Added user $USER ($COMMENTS) with pass $PASSWORD"
}

## Main script starts here

adduser bob letmein Bob Holness from Blockbusters
ADDUSER_RETURN_CODE=$?
if [ "$ADDUSER_RETURN_CODE" -eq "1" ]; then
  echo "Something went wrong with useradd"
elif [ "$ADDUSER_RETURN_CODE" -eq "2" ]; then 
   echo "Something went wrong with passwd"
else
  echo "Bob Holness added to the system."
fi

EDITOR=vi; export EDITOR

# (put your own initials here)echo the date to the console every
# 15minutes between 6pm and 6am
0,15,30,45 18-06 * * * /bin/echo 'date' > /dev/console

$ crontab davecron

$ crontab -l