Unix File Comparision

Shell Programming and Scripting
1

I have a file named file1 which contains numbers in sequence like...
1
2
3
7
8
Then i have file File 2 that contains
4
5
........so i need to compare both files so that i can find out the missing entry in the sequence is 6.......These files are flat files which contain and so i need to write a script that takes as input these 2 files.
I guess i cant use diff command or comm command for this , if i can how can i do it plz let me know guys.

2

I get this result:

kcsdev:/home/jmcnama> cat file1 
1
2
3
4
5
7
8

kcsdev:/home/jmcnama> cat file2
9
10

kcsdev:/home/jmcnama> s.sh
 6 is missing

from this code:

#!/bin/ksh
# script = s.sh
let expected=1
for i in $( cat file1 file2 | sort -n -u)
do
    if [[ $expected != $i ]] ; then
        echo " $expected is missing"
        break
    fi
    let expected=$expected+1
done
3

hey thanks for the reply......but i dont understand how u can get the missing nos from the sequence in both the files.............if i have 2 files like file1 containing
1
2
5
and then file2...
3
then i need to find out that 4 is the missing no in the sequence from both the files.........

4 
#!/bin/ksh
# script = s.sh
let expected=1
for i in $( cat file1 file2 | sort -n -u)
do
    if [[ $expected != $i ]] ; then
        echo " $expected is missing"
        expected=$i       
    fi
    let expected=$expected+1
done

This reports multiple missing elements. The example you gave above only was missing "6". If you need to find which file is missing what nubmer, use grep -q on the original files to locate the file that is missing the number.

5

Deleting the post

6 
$ cat 11
1
2 
3
7
8

$ cat 22
4
5
11

$ cat 11 22 | sort -n -u | ./a
6
9
10
$ cat a
#!/bin/awk -f
BEGIN {
    i = 1;
}
/^[0-9]+/ {
    while (i < $1) {
        print i;
        i++;
    }
    i++;
}