Read a number from file and place it back

Shell Programming and Scripting
1

Hi All,

I want to read one number from the file.
Only one number will be there in the file.
then i have to increment the number in my script and put it back in the same file.

Is it possible?
Can anybody help me?

Thanks,
Vinay

2

Something like this?

awk '$0++' file > newfile && mv newfile file

Regards

3

Hi Franklin,

I want to place the incremented value in the same old file.

say my file name is "file.txt" which has number 5 in it.

once i run the script, this value should be taken and 6 should be placed in the file "file.txt".

I think you got my requirement.

Thanks
Vinay

-----Post Update-----

Hi Franklin,

It is working fine.
Thanks a lot...:b:

Regards
Vinay

4

Vinay,
Try this code:

read i < a
i=`expr $i + 1`
echo $i > a
cat a

It is working perfectly fine in bash.

Here "a" is a file name where the number is stored & "i" is a temp variable.

Let me know if you need any more info.

5

Hi Dcoolsam,

Thanks a lot ,,,,
Your code suits my requirement.
But one change is needed, here it is printing the number also in echo line...
i dont want to print that,,,
how can i fix it...

Regards
Vinay

6

Hey Vinay,
Your task is getting accomplished by just first 3 lines of my code.
Last line is just to print that value.
You can remove that last line : cat a

You check the incremented value in the file.
It will be incremented.

Cheers....:slight_smile:

7

Hi Dcoolsam,

Yes i checked. It is working properly.
Thanks a lot,,,,:slight_smile:

Regards,
Vinay