Arithmetic syntax error

Shell Programming and Scripting
1

Hello,

I am new to shell scripting and getting the error "arithmetic syntax error" on line 55 of my script.

Below is line 55 and 56

    Backup=$ (( $Year*365+$Day ))
if [[ $PrevHostname = '' ]] then PrevHostname=$Hostname; PrevBackup=$Backup

Error:

./mksysbChk.ksh: line 56:  *365+as : arithmetic syntax error

Any help to fix this will be appreciated.

Thanks,

2 
(( Backup = Year * 365 + Day ))
3

Sorry, I did not get that. Remove the $ signs and include Backup with the brackets?

---------- Post updated at 03:51 PM ---------- Previous update was at 03:34 PM ----------

After the suggested edit; I get the below error

syntax error at line 56: `((' unexpected
4

You can't have a space between the $ and the (( . So, change:

    Backup=$ (( $Year*365+$Day ))

to:

    Backup=$(( $Year*365+$Day ))

Inside an arithmetic expansion (i.e., $((expression)) ), shell variable expansions that expand to numeric strings can be specified using $variable_name or variable_name , so the above can also be specified as:

    Backup=$(( Year*365+Day ))

and get the same results.

5

The *365+as in the error message is a bit suspect. What be the contens of $Day ?

6 
let Backup=$Year*365+$Day
7 
Day=`date|cut -c9-10`                          # into Month(Mmm), Day(##) & Year(##)

---------- Post updated at 04:06 PM ---------- Previous update was at 04:02 PM ----------

Backup=$Year*365+$Day works. Thanks

However, I get an email failure message;

Final-Recipient: RFC822; hasn318@****.com
Action: failed
Status: 5.0.0
Diagnostic-Code: SMTP; 550 Not permitted
Last-Attempt-Date: Wed, 5 Oct 2016 17:03:40 -0400
8

The email diagnostic shown above has absolutely nothing to do with any of the code you have shown us in this thread.

9

Don't rely on your Day variable containing a correct number:

date|cut -c9-10
 0
/bin/date|cut -c9-10
t 
/bin/date -R|cut -c9-10
Oc
10

calculate day using date +%d

$ day=$(date +%d)
$ echo ${day#0}
6
11

Seems like the month is missing in your backup calculation, so identical values will repeat 12 times a year...