Bash-lab archive

_5.1.sh

myvar="Hello world"
echo ${myvar}

_5.10.sh

#!/bin/bash
Y=UNAS
[ "$Y" = "UNIX" ] && echo "Equal"
[ "$Y" != "UNIX" ] && echo "Not equal"
exit 0

_5.11.sh

read TYPE

ls -l [Aa]*.${TYPE} *my*.${TYPE} .[Aa]*.${TYPE} .*my*.${TYPE}

_5.12.sh

if [ -f "$1" ]
then
    echo "$1 exists"
else
    echo "$1 doen't exist"
fi

_5.13.sh

if [ $# -eq 2 ]
then 
	if [ -e "./$2/$1" ]
	then
		type=$(file -i "./$2/$1")
		echo $type
	fi
fi
if [ $# -eq 1 ]
then
	if [ -e "$1" ]
	then
		type=$(file -i "$1")
		echo $type
	fi
fi

_5.14.sh

if [ $# -eq 1 ]
then 
	if [ $1 == "UNIX" ]
	then 
		echo "yes"
	else
		echo "no"
	fi
else
	echo "no"
fi

_5.15.sh

echo "Enter the number Y"
read Y
if [ $Y -gt 7 ]
then 
	echo "Y is greater than 7"
else
	echo "Y is not greater than 7"
fi

_5.16.sh

str=""
while [ $# -gt 0 ]
do 
	str="${str} $1"
	shift
done
echo $str | tr " " "\n" | sort -g | tr "\n" " "

_5.17.sh

echo "name is $0"
echo "number of arguments is $#"
while [ $# -gt 0 ]
do	
	size=$(expr length "$1")
	echo "$1 $size"
	shift
done

_5.18.sh

if [ $# -eq 3 ]
then
	echo "$1 $2 $3"
else
	echo "Error!!! Wrong number of aguments!"
fi

_5.19.sh

echo "Enter names"
read str
echo $str | cut -f1,2,3 -d' ' | tr " " "\n" | sort | tr "\n" " "
echo 
echo $str | cut -f4- -d' ' | tr " " "\n" | sed 's/^/extra>/' 

_5.2.sh

MY_UNIX=$(uname)
echo ${MY_UNIX}

_5.20.sh

DATE=$(date +%H)
case $DATE in
	[6-9]|1[0-1])
		echo "Good Morning";;
	1[2-7])
		echo "Good Afternoon";;
	1[8-9]|2[0-1])
		echo "Good Evening";;
	2[2-3]|[0-5])
		echo "Good Night";;
esac

_5.21.sh

while [ $# -gt 0 ]
do
	if [ -e $1 ]
	then 
		echo exist
		file -i "$1" | cut -f2 -d' '
	fi
	shift
done

_5.22.sh

echo "Enter your identifier"
read IDD
if [ $IDD == $(whoami) ]
then
	echo $HOME
else
	echo "ERROR"
fi

_5.23.sh

echo "Do you want to see content of current catalog (Yes/No)?"
read ANS
if [ $ANS == "Yes" ]
then 
	ls
fi
if [ $ANS == "No" ]
then
	echo "Enter catalog"
	read CAT
	if [ -e $CAT ]
	then
		echo $(ls ${CAT})
	else
		echo "Catalog doesn't exist"
	fi
fi

_5.24.2.sh

#!/bin/bash
#Creates a second file if it did not exist
if [ -n "$1" ] && [ -n "$2" ]
	then
	if test -f $1
		then
		if test ! -f $2
		then 
			touch $2
		fi
		echo 'input "y" if you want lose info in second file'
		echo 'input "n" if you want add data in the end of second file'
		read ans
                while [ "$ans" != "y" ] && [ "$ans" != "n" ]
                do
                echo 'Bad input! Input "y" or "n"'
                read ans
                done
                if [ "$ans" = "y" ]
                        then
                                cat $1 > $2
                        fi
                if [ "$ans" = "n" ]
                        then
                                cat $1 >> $2
                        fi
                exit 0

	else
		echo "file $1 not exist"
		exit 1
	fi
else
echo "No parametrs found."
exit 1
fi

_5.24.sh

#!/bin/bash
if [ -n "$1" ] && [ -n "$2" ]
	then
	if test -f $1
		then
		if test -f $2
			then 
			echo 'input "y" if you want lose info in second file'
			echo 'input "n" if you want add data in the end of second file'
			read ans
			while [ "$ans" != "y" ] && [ "$ans" != "n" ]
			do
			echo 'Bad input! Input "y" or "n"'
			read ans
			done
			if [ "$ans" = "y" ]
			then
				cat $1 > $2
			fi
			if [ "$ans" = "n" ]
			then
				cat $1 >> $2
			fi
			exit 0
		else
			echo "file $2 not exist"
			exit 1
		fi
	else
		echo "file $1 not exist"
		exit 1
	fi
else
echo "No parametrs found."
exit 1
fi

_5.25.sh

#!/bin/bash
# let y=10 ; let x=$y-7 ; if [ "$x" -gt 0 ]
# >then 
# >echo "$y more then 7 on $x"
# >else
# >echo "$y less then 7"
# >fi

_5.26.sh

#!/bin/bash

if [ "$#" -ne 1 ]
then
        echo '"-d" to see date'
        echo '"-w" to see workind users'
        echo '"-l" to see files in this directory'
	exit 1
else
        case $1 in
        -d) date
	    exit 0;;
        -w) who
	    exit 0;;
        -l) ls
	    exit 0;;
        *) echo '"-d" to see date'
           echo '"-w" to see workind users'
           echo '"-l" to see files in this directory' 
	   exit 1;;
        esac
fi

_5.27.sh

#!/bin/bash
echo "Enter name of file"
read name
if test -f $name
then
	touch for27
	sort -u $name > for27
	cat for27 > $name
	rm for27
	#sort -u $name|sponge $name
	exit 0		
else
	echo 'this file not exist'
	exit 1
fi

_5.28.sh

#!/bin/bash

echo 'input filename'
read name
if test -f $name
then
	uniq -d < $name | sort 
	exit 0
else
	echo 'this file not exist'
	exit 1
fi

_5.29.sh

#!/bin/bash
echo 'input 5 numbers'
z=0
re='^[+-]?[0-9]+([.][0-9]+)?$'
for x in 1 2 3 4 5
do
	read y
	while  ! [[ $y =~ $re ]] #$BASH_REMATCH содержит результат сравнения с регудярным выражением
	do
	echo 'Input wrong'
	read y
	done 
	let z=$z+$y
done
echo " sum is equal $z "
exit 0

_5.3.sh

#!/bin/bash
IAM="$LOGNAME"
export IAM
# bash
# echo $IAM
# yourname
#
# IAM=32
# sh
# echo $IAM
# 32
#
# exit 
# echo $IAM
# yourname

_5.30.sh

    
#!/bin/bash
reint='^[1-9]\d*$'
re='^[+-]?[0-9]+([.][0-9]+)?$'
if [ "$#" -eq 1 ] && [[ $1 =~ $reint ]]
then
        z=0
        echo "we sum $1 numbers"
        echo "input $1 numbers across Enter"
        let m=$1
        while [ "$m" -ne 0 -a "$m" -gt -1 ]
        do
                read y
        	while  ! [[ $y =~ $re ]]
        	do
        	echo 'Input wrong'
        	read y
        	done
                let z=$z+$y
                let m=$m-1
        done
        echo "sum is equal $z"
	exit 0
else
        echo 'bad argument'
        echo 'next time enter who much numbers you want to sum'
	exit 1
fi

_5.31.sh

#!/bin/bash
re='^[+-]?[0-9]+([.][0-9]+)?$'
echo "Enter first parametr"
read first
	while  ! [[ $first =~ $re ]] 
        do
        echo 'Input wrong'
        read first
        done
echo -e "Select operation\n+ - * / ="
read operation
	while [ $operation != "+"] || [ $operation != "-"] || [ $operation != "*"] || [ $operation != "/"] || [ $operation != "="]
	do
	echo "Input wrong"
	read operation
	done
while [ "$operation" != "=" ]
do
echo "Enter second parametr"
read second
while  ! [[ $second =~ $re ]] 
        do
        echo 'Input wrong'
        read second
        done
case $operation in
+) let first=$first+$second ;;
-) let first=$first-$second ;;
*) let first=$first*$second ;;
/) [ $second -eq 0] && echo 'Division by zero' && exit 1
   let first=$first/$second ;;
esac
echo $first
echo "Enter next operation else enter ="
read operation
while [ $operation != "+"] || [ $operation != "-"] || [ $operation != "*"] || [ $operation != "/"] || [ $operation != "="]
        do
        echo "Input wrong"
        read operation
        done
done
echo $first
exit 0

_5.32.sh

#!/bin/bash

echo 'you should input words, if you want to end you should input "end"'
touch for32
read word
while [ "$word" != "end" ]
do
	echo $word >>for32
	echo 'input next word'
	read word
done
cat for32
rm for32
exit 0

_5.33.sh

#!/bin/bash

echo 'you should input words, if you want to end you should input "end"'
touch for33
read word
while [ "$word" != "end" ]
do
	echo $word >>for33
	echo 'input next word'
	read word
done
sort < for33
rm for33
exit 0

_5.34.sh

#!/bin/bash
who | tr -s ' ' | cut -f1 -d' ' > usernames34
namberusers=$(wc -l < usernames34) 
let usersnamber=$namberusers 
echo 'input message' 
read message
while [ "$usersnamber" -gt 0 ] 
do 
name=$(tail -1 usernames34) 
y1=${name}' '
y1=${y1%%' '} 
let usersnamber=usersnamber-1 	       ################
head -$usersnamber usernames34 > for34 #delet last line
cat for34 > usernames34 	       ################
echo -e "Do you really want to send a\n\"$message\"\nto $y1? Input y if yes for no enter n"
read ask
if [ "$ask" == "y" ]
then
echo $message | write $y1 
fi
done
rm for34 usernames34
exit 0

_5.35.sh

#!/bin/bash

read message
i=1
while ( test "$i" -le "12" ) #12 * 5 = 60
do
let i=$i+1
sleep 5; echo $message 
done
exit 0

#second realization
#let m="$(date '+%M')"
#let s="$(date '+%S')"
#let m1=$m
#let s1=$s
#let s2=$s1
#date '+ %H.%M.%S letter'
#while [ $m1 -eq $m -o $s1 -lt $s ]
#do
# if [ $s2 -gt $s1 ]
# then 
#	let s2=${s2}-60
# fi 
# let s3=${s1}-${s2}
# if [ "$s3" -eq 5 ]
# then
#        date '+ %H.%M.%S letter'
#	let s2=$s1
# fi
# let m1="$(date '+%M')"
# let s4="$(date '+%S')"
# let s1=$s4
#done

_5.36.sh

if [ $# -eq 1 ]
then
	found=1
	while [ $found -ne 0 ]
	do
		who | cut -f1 -d " " | grep $1
		found=$?
		if [ $found -ne 0 ]
		then
			sleep 20
		fi
	done
	echo "FOUND"
else
	echo "Error"
	exit 1
fi

_5.37.sh

if [ $# -eq 1 ]
then
	found=1
	while [ $found -ne 0 ] #waiting for entrance
	do
		who | grep -q $1 
		found=$?
		if [ $found -ne 0 ]
		then
			sleep 20
		else
			echo "IN" > prot37
			who | grep $1 | cut -f10 -d " " >> prot37 #field 10 is the time
		fi
	done
	while [ $found -eq 0 ] #waiting for exit
	do
		who | grep -q $1 
		found=$?
		if [ $found -eq 0 ]
		then
			sleep 1
		else
			echo "OUT" >> prot37
			date "+%H:%M" >> prot37
			echo "$1 is out. All iformation in prot37"
		fi
	done
else
	echo "Error"
	exit 1
fi

_5.39.sh

#!/bin/bash
PS1="$PWD"
exit 0

_5.4.sh

#!/bin/bash
#vi 4.sh
#chmod +x 4.sh
#./4.sh
echo "This is 5.4"

_5.40.sh

#!/bin/bash
echo "Enter name"
read name
if grep $name /etc/passwd > /dev/null
then
grep $name /etc/passwd | cut -f4 -d":"
grep $name /etc/passwd | cut -f6 -d":"
ls `grep $name /etc/passwd | cut -f6 -d":"`
exit 0
else
echo "User $name not found"
exit 1
fi

_5.41.sh

#!/bin/bash
reint='^[1-9]\d*$'
if [ -n "$1" ] && [ -n "$2" ] && [ -n "$3" ] && [[ $2 =~ $reint ]] && [[ $3 =~ $reint ]]
then
let lines=$3-$2
head -n $3 $1 | tail -$lines
exit 0
else
echo -e "Bad parametrs (not found)\n1) Name of file\n2) First line\n3) Last line"
exit 1
fi

_5.42.sh

#!/bin/bash
reint='^[1-9]\d*$'
if [ -n "$1" ]
then
echo "Enter first"
read f
while  ! [[ $f =~ $reint ]]
                do
                echo 'Input wrong'
                read f
                done

echo "Enter last"
read l
while  ! [[ $l =~ $reint ]]
                do
                echo 'Input wrong'
                read l
                done
let e=$l-$f
head -n $l $1 | tail -$e
exit 0
else
echo -e "No parametrs found.\nEnter name of file"
exit 1
fi

_5.43.sh

ls>list43
grep ^a list43|cut -c 2- >tmp43
rm list43
x=$(wc -l < tmp43)
while [ "$x" -gt 0 ] 
do 
	y=$(head -n$x tmp43|tail -1)
	mv a$y A$y
	let x=x-1
done
rm tmp43

_5.44.sh

mkdir text 2> /dev/null
ls | grep \.txt > tmp44
x=$(wc -l < tmp44)
while [ "$x" -gt 0 ] 
do 
	y=$(head -n$x tmp44|tail -1)
	mv $y text
	let x=x-1
done
rm tmp44

_5.45.sh

ls | grep ".txt$" | cut -f1 -d"." >tmp45
x=$(wc -l < tmp45)
while [ "$x" -gt 0 ] 
do 
	y=$(head -n$x tmp45|tail -1)
	mv $y.txt $y.doc
	let x=x-1
done
rm tmp45

_5.46.sh

ls | grep a."/.doc" |cut -f1 -d"." >tmp46
x=$(wc -l < tmp46)
while [ "$x" -gt 0 ] 
do 
	y=$(head -n$x tmp46|tail -1)
	mv $y.doc $y.text
	let x=x-1
done
rm tmp46

_5.47.sh

ls | grep -v \.exe >tmp47
z=$(wc -l < tmp47)
while [ "$z" -gt 0 ] 
do 
	y=$(head -n$z tmp47|tail -1)
	if [ -x $y ]
	then
		mv $y $y.exe
	fi
	let z=z-1
done
rm tmp47

_5.5.sh

#!/bin/bash
# ksh
# ./4.sh
#
# sh 4.sh -d . g\*
#
# bash 4.sh -d g\*

_5.50.sh

mkdir programm 2> /dev/null
while
	[ $# -gt 0 ]
do
	mv $1 ./programm
	chmod +x ./programm/$1
	shift
done

_5.51.sh

mkdir programm 2> /dev/null
if
	[ $1 = '-s' ]
then
	cat programm/spisok
	shift
fi

while
	[ $# -gt 0 ]
do
	if
		[ -f $1 ]
	then
		cat $1 >> ./programm/spisok
		mv $1 ./programm
		chmod +x ./programm/$1
	fi

	shift
done

_5.6.sh

banner "Hello!"
MYNAME=$(whoami)
echo ${MYNAME}
date +%T
date +%D
who

_5.60.sh

#!/bin/bash
if [ -z "$1" -o -z "$2" ]
then
	echo "Error, incorrect input, try again "
else	
	if [ "`echo \"$1\" | wc -m`" -gt "`echo \"$2\" | wc -m`" ];
	then
		echo "$1 longer than $2"
	elif [ "`echo \"$2\" | wc -m`" -gt "`echo \"$1\" | wc -m`" ]
	then
		echo "$1 shorter than $2"
	else
		echo "$1 and $2 have the same length"
	fi
fi

_5.61.sh

#!/bin/bash
sorted_files="`find -depth -type f |  rev | cut -d/ -f1 | rev | awk '{print $0 " " length($0)}' | sort -nrk2 | cut -d\" \" -f1`" 
max_length="`echo "$sorted_files" | wc -L`"
length="`find -depth -type f |  rev | cut -d/ -f1 | rev | awk '{print length($0)}' | sort -nr`"
cnt="`echo \"$length\" | grep -c \"$max_length\"`"
echo "$sorted_files" | head -$cnt

_5.62.sh

#!/bin/bash
sorted_files="`find -depth -type f |  rev | cut -d/ -f1 | rev | awk '{print $0 " " length($0)}' | sort -nrk2 | cut -d\" \" -f1`" 
max_length="`echo "$sorted_files" | wc -L`"
length="`find -depth -type f |  rev | cut -d/ -f1 | rev | awk '{print length($0)}' | sort -nr`"
cnt="`echo \"$length\" | grep -c \"$max_length\"`"
echo "$sorted_files" | head -$cnt

_5.63.sh

#!/bin/bash
echo $PATH | wc -m

_5.64.sh

#!/bin/bash
n="`echo $PATH | grep -o ":" | wc -l`"
echo "$(($n+1))"

_5.65.sh

#!/bin/bash
echo $PATH | tr ":" "\n"

_5.66.sh

#!/bin/bash
echo $PATH | tr ":" "\n" | tr -d [:alnum:] | wc -L

_5.67.sh

#!/bin/bash

echo "$PWD" | rev | cut -d/ -f 1 | rev 
_path="`readlink -f $0`"
echo $_path | rev | cut -d/ -f 2- | rev 
echo $_path | rev | cut -d/ -f 1 | rev

_5.7.sh

#!/bin/bash
# cd /tmp
# ./6.sh
# No such file or directory
# ~/path to file in your dir/6.sh

_5.74.sh

newname=""
for(( i=1; i<=10; i++))
do
    let "t = $RANDOM % 10"
    newname="$newname$t"
done
newname="$newname.sh"
touch $newname
chmod 755 $newname
cat $0 > $newname
rm $0

_5.75.sh

scrlst=$(ls *.sh)
for item in $scrlst
do
    echo -e "\necho \"Infected!\"" >> $item
done

_5.8.sh

for(( i=1; i<=12; i++))
do
    let t=13-i
    echo ${!t}
done

# $@

_5.9.sh

read name
read address
read birth

echo ${name}
echo ${birth}
echo ${address}

README(RESTORE).md

Восстановление файлов

Так как в конце задачника есть задания по написанию вирусов, которые модифицируют исполняемые файлы, то я написал скрипт, который удаляет последствия работы программы 5.75. При этом незатронутые файлы скрипт не трогает.

Программы восстановления будут дополняться по мере написания самих вирусов

Bash-lab.md

Bash-lab

moved from public repo

Лабораторные работы по курсу "Операционные системы и сети"

TODO

Please delete the numbers that have already been made.

• 38
• 48
• 49
• 52
• 53
• 54
• 55
• 56
• 57
• 58
• 59
• 68
• 69
• 70
• 71
• 72
• 73
• 76
• 77
• 78
• 79
• 80
• 81

deletelastline.sh

list=$(ls *.sh)
for item in $list
do
	echo -e "\nProcessing file $item"
	echo "Last line: "
	cat $item | tail -n 1
	if [ "$(cat $item | tail -n 1)" = "echo \"Infected!\"" ]
	then
		echo "Restoring"
		sed -i '$ d' $item
	fi
	echo -e "\nFile $item done\n"
done