Unix Lab Manual Part B PDF

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IV BCA - Unix Lab Manual Part - B 11. Execution of various file/directory handling commands. 1) pwd COMMAND: pwd - Print Working Directory. pwd command prints the full filename of the current working directory. SYNTAX: The Syntax is pwd [options] 2) cd COMMAND: cd command is used to change the direc...

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IV BCA - Unix Lab Manual Part - B 11. Execution of various file/directory handling commands. 1) pwd COMMAND: pwd - Print Working Directory. pwd command prints the full filename of the current working directory. SYNTAX: The Syntax is pwd [options] 2) cd COMMAND: cd command is used to change the directory. SYNTAX: The Syntax is cd [directory | ~ | ./ | ../ | - ] 3) ls COMMAND: ls command lists the files and directories under current working directory. SYNTAX: The Syntax is ls [OPTIONS]... [FILE] OPTIONS: -l Lists all the files, directories and their mode, Number of links, owner of the file, file size, Modified date and time and filename. -t Lists in order of last modification time. -a Lists all entries including hidden files. -d Lists directory files instead of contents. -p Puts slash at the end of each directories. -u List in order of last access time. -i Display inode information. 4) rm COMMAND: rm linux command is used to remove/delete the file from the directory. SYNTAX: The Syntax is rm [options..] [file | directory] OPTIONS: -f Remove all files in a directory without prompting the user. -i Interactive. With this option, rm prompts for confirmation before removing any files.

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5) mv COMMAND: mv command which is short for move. It is used to move/rename file from one directory to another. mv command is different from cp command as it completely removes the file from the source and moves to the directory specified, where cp command just copies the content from one file to another. SYNTAX: The Syntax is mv [-f] [-i] oldname newname OPTIONS: -f This will not prompt before overwriting (equivalent to -reply=yes). mv -f will move the file(s) without prompting even if it is writing over an existing target. -i Prompts before overwriting another file.

6) cat COMMAND: cat linux command concatenates files and print it on the standard output. SYNTAX: The Syntax is cat [OPTIONS] [FILE]... OPTIONS: -A Show all. -b Omits line numbers for blank space in the output. -E Displays a $ (dollar sign) at the end of each line. -n Line numbers for all the output lines. 7) cp COMMAND: cp command copy files from one location to another. If the destination is an existing file, then the file is overwritten; if the destination is an existing directory, the file is copied into the directory (the directory is not overwritten). SYNTAX: The Syntax is cp [OPTIONS]... SOURCE DEST 8) echo COMMAND: echo command prints the given input string to standard output. SYNTAX: The Syntax is echo [options..] [string] 9)mkdir COMMAND: mkdir command is used to create one or more directories. SYNTAX: The Syntax is mkdir [options] directories Unix Lab Manual -B

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OPTIONS: -m Set the access mode for the new directories. -p Create intervening parent directories if they don't exist. -v Print help message for each directory created. 10) rmdir COMMAND: rmdir command is used to delete/remove a directory and its subdirectories. SYNTAX: The Syntax is rmdir [options..] Directory OPTIONS: -p Allow users to remove the directory dir name and its parent directories which become empty.

12. Shell script to check whether the given number is even or odd. clear echo "enter a number" read n if [ `expr $n % 2` -eq 0 ]; then echo " $n is even" else echo "$n is odd" fi

13. Shell script to find gcd and lcm of given two numbers. clear echo "Enter two intergers" read m n echo " To find GCD and LCM" echo "====================" echo "given two numbers are" echo "m= $m and n=$n" temp=`expr $m \* $n`

while [ $m != $n ] do Unix Lab Manual -B

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if [ $m -gt $n ] then m=`expr $m - $n` else n=`expr $n - $m` fi done echo GCD=$n lcm=`expr $temp / $n` echo LCM=$lcm

14.Shell script to create a simple calculator that performs basic arithmetic operations clear sum=0 i="y" echo " Enter one no." read n1 echo "Enter second no." read n2 while [ $i = "y" ] do echo "1.Addition" echo "2.Subtraction" echo "3.Multiplication" echo "4.Division" echo "Enter your choice" read ch case $ch in 1)sum=`expr $n1 + $n2` Unix Lab Manual -B

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echo "Sum ="$sum;; 2)sum=`expr $n1 - $n2` echo "Sub = "$sum;; 3)sum=`expr $n1 \* $n2` echo "Mul = "$sum;; 4)sum=`expr $n1 / $n2` echo "Div = "$sum;; *)echo "Invalid choice";; esac echo "Do u want to continue ?" read i if [ $i != "y" ] then exit fi done

15. Shell script to reverse a given string clear echo "enter the string" read str len=`expr $str | wc -c` len=`expr $len - 1` while [ $len -gt 0 ] do ch=`echo $str | cut -c $len` Unix Lab Manual -B

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echo -n $ch len=`expr $len - 1` done

16.Shell script to wish according to day time. clear hours=`date|cut -c12-13` if [ $hours -le 12 ] then echo "Good Morning" else if [ $hours -le 16 ] then echo "Good Afternoon" elif [ $hours -le 20 ] then echo "Good Evening" else echo "Good Night" fi fi

17.Shell script to assign a file permission to a given file using a) symbolic mode b) absolute mode clear option=y while [ $option = y ] do echo "1. Symbolic mode Unix Lab Manual -B

2. Absolute mode" Page 6

echo "enter your choice" read ch

case $ch in 1) clear echo "changing the file permission in symbolic mode" echo `pwd` contents are ls -l echo "enter the file name" read fname echo "enter the file type u/g/o" read type echo "enter one of the permission r/w/x" read permission #changing the mode with given input chmod $type+$permission $fname echo "after changing the permission" ls -l echo;; 2) clear echo "changing the permission is absolute mode" echo `pwd` contents are ls -l echo "enter the filename" read fname echo "enter the permission" read permission chmod $permission $fname echo "after changind the file permission" ls -l Unix Lab Manual -B

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echo;; esac echo "do you want to continue y/n " read option

18.Shell program to compression and decompression of files using gzip and gunzip clear echo "enter the file name" read fname echo "size of $file name before compression is" wc -c $fname gzip $fname echo "size of file name after compression" wc -c $fname.gz #unzip the file gunzip $fname.gz echo "after decompression $fname" wc -c $fname echo $fname

19.To search a pattern using grep and fgrep command clear echo "enter the file name" read fname1 echo "enter the contents of $fname1 and press ctrl+d" cat >$fname1 echo "enter the file name 2" read fname2 echo "enter the contents of $fname2 and press ctrl+w"

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cat >$fname2 echo "enter the pattern" read ptrn #echo $ptrn $fname1 $fname2 grep -i $ptrn $fname1 $fname2 fgrep -i $ptrn $fname1 $fname2

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Menu driven shell script to demonstrate the use of tail , cmp, uniq and rm commands clear opt=y while [ $opt = y ] do clear echo "----------Menu driven program --------" echo echo echo "1. Usage of tail command " echo echo "2. Usage of cmp command" echo echo "3. Usage of uniq command" echo echo "4. Usage of rm -r command" echo echo "enter your choice" read ch case $ch in 1) clear echo "================================" echo "tail displays lines from bottom of the file" echo

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printf "enter number of lines to display" read n echo echo last $n lines of file temp " echo "------------------------" echo tail -$n temp;; 2) clear echo "================================" echo "cmp compares two files and gives the point of difference" echo echo temp1 and temp2 are compared echo "------------------------" echo cmp temp1 temp2;; 3) clear echo "================================" echo "uniq eliminates adjacent duplicate lines" echo "=======================================" echo echo unique lines of temp1 echo echo "------------------------" cat temp1 | sort | uniq;; 4) clear echo "================================" echo " rm -r deletes the directory along wih contents" echo "=============================================" echo echo "enter the subdirectory name" read subdir Unix Lab Manual -B

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mkdir $subdir cd $subdir touch file1 file2 echo current directory is `pwd` cd .. if rm -r $subdir then echo $subdir removed succesffully fi;; *) echo "invalid choice" esac echo "do you like to continue ?" read opt done echo tail -$n temp;;

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