i need to store the outputs of 2 commands in 2 variables and compare the two variable
 

i need to compare the output from the md5sum of 2 files
when i run this script i get the output is wrong


1
yes
2
yes
3
yes
4
yes
5
yes

here is the script

g=`tail -1 new.txt|head -n 1`# for reading a value from new.txt

for (( i=1; i<$g+1; i++ ))
do
echo $i
a=`md5sum data$i`
b=`md5sum dat`


if [ "$a"=="$b" ]
then
echo yes
else
echo no
fi

done

actually only data1 is same as dat but the rest are different but i get yes for values of i.
can anyone please help me?

Not sure if it is the only problem with your script, but you should use "=" not "==" in your if test.

Evo2.

i changed the "==" to "=" and still i get the same output

You should echo the values of $a and $b in the script so that you can see what they are.

Evo2.

1
6b465c608623058c4ccf24149012dfa3 data1
6b465c608623058c4ccf24149012dfa3 dat
yes
2
2559d5fd84bfadaf77bb63fd0459e23a data2
6b465c608623058c4ccf24149012dfa3 dat
yes
3
5f977efefe9e832a30b2ca874a552386 data3
6b465c608623058c4ccf24149012dfa3 dat
yes
4
5f977efefe9e832a30b2ca874a552386 data4
6b465c608623058c4ccf24149012dfa3 dat
yes
5
c173ba16e9f6b482653760b675f57a01 data5
6b465c608623058c4ccf24149012dfa3 dat
yes


this is the output i get

Actually even the first one should not match since a ends in "data1" and b ends in "dat". Anyway the problem seems to be that you did not leave a space either side of the "=" in the if statement.

Evo2.

Is your script running as a bash script or as something else? You can ensure that it is run as a bash script by using this first line
= and == are both valid bash string comparison operators but they must be surrounded by spaceBTW, [[ ]] is preffered over [ ] for reasons explained here.

It's easier to read your code if you put it in code tags (that's a link to instructions or you may prefer to use "Advanced Edit" mode which has a # button for code tags).

oh ok .. you're right.. when i added the space .. i got all of them as no.. is there anyway of preventing md5sum from printing the filename?

You can just cut out the field you want.
Also you you only need to set b once, at teh start of the script.

Evo2.

it works ! thanx

Glad you got a solution. Please mark the thread SOLVED using the Thread Tools menu.