hi, i want full solution of following five as shell programe in unix- 1)to search a number in a given list of numbers. 2) to reverse a seven digit number and find the sum of all the digits. 3)to sort a given list of numbers in descending order. 4)to count the number of positive and negative number in a given list. 5)to check that a given number is a perfect number or not. please help me .kindly send me solution

OK Bob, I'll take "doing someone else's homework, question 1" for 200, please. cat number.txt 1 2 3 4 5 var=5 grep $var number.txt 5

Hi: OK, I'll do #3: Using David's number.txt file: sort -nr number.txt Let assume number.txt has more than one column, and we're sorting by the 3rd column: sort -nrk3,3 number.txt Regards, nails

Hi, My attempt on #2. To reverse a number do something like: number=1234567 echo $number | rev To find sum of all digits do something like: echo 1234567 | rev | read number sum=0 while [[ $number > 0 ]] do t1=$((number/10)) t2=$((t1*10)) reminder=$((number-t2)) number=$((number/10)) sum=$((sum+reminder)) done echo $sum

OK, guess I'll take #2 ... #!/bin/ksh if [ $# -ne 1 ] ; then    echo 'Need one parameter: 7-digit number'    exit 1 fi number=$1 if [ $(expr $number : "[0-9]*$") -ne 7 ] ; then    echo 'Sorry, I need exactly 7 DIGITS'    exit 1 fi reversed=$(echo $number|rev) echo $reversed |    sed "s/./&+/g;s/.$//" |    bc |    read total echo "\n  number:      $number" echo "  reversed:    $reversed" echo "  digit sum:   $total\n" exit 0 $ ./prob2.sh 1234567   number:     1234567   reversed:    7654321   digit sum:   28

Sorry Jigujigu, your reply was not there when I started. Looks like a good solution, and pure shell, whereas I used sed.

For #5, you need to know what is and is not a prime number. #!/bin/sh IFS=':' export IFS i=1 ; while [ $i -lt 100000 ] ; do if [ `factor $i | awk '{ print $2 }'` -eq $i ] ; then echo "$i is prime" ; fi ; ((i=i+1)) ; done http://home.pacific.net.sg/~novelway/MEW2/lesson1.html