Arithmetic Operations

[olli2003]

Hi guys

Can someone of you tell me how to do arithmetic operations within a shell script?
For explaining, I've two output files with digits in it. Every file contains one digit. So now I'd like to add or subtract this two digits and want to create a new file with it's output. Is it possible and how?
Many thanks and best regards!
Oliver

 

[alexhu]

Checkout 'expr' in the man pages

Sorry for only 1 example the rest of the page does not format very well

Alex


Example
To modify a shell variable, enter:
COUNT=`expr $COUNT + 1`
This adds 1 to the shell variable $COUNT. The expr command is enclosed in grave accents, which causes the shell to substitute the standard output from the expr command into the COUNT= command. The $COUNT variable must be initialized before using.

 

[MoshiachNow]

Also,Have a look at:

http://publib.boulder.ibm.com/doc_l...xuser/usrosdev/arithmetic_eval_korn_shell.htm

"Long live king Moshiach !"

http://www.7for70.com/

 

[dsn1]

Assuming that the files only contain the digits to be added

expr $(cat file1) + $(cat file2) > file3

Dave

 

[olli2003]

Hi Dave

That's what I wanted to know -
really easy if you know.
Thanks a lot and also to each others tried to help me!

Best Regards
Oliver

 

[Dominik81]

Hello

Can someone of you tell me how to do arithmetic operations with floating-point numbers within a shell script?

Dominik

 

[victorv]

hi,
Dominik

I use the command bc (that you can use from shell) as

X1=2.2222222222
X2=3.3333333333
XT=`echo "$X1 + $X2" | bc`
echo $XT

bye

 

[Dominik81]

Thnak you!

That`s what I need.

Dominik