Find the last Saturday of the month in a bash script

Question

I'm making a backup script in which I need to find the last Saturday of each month. I've tried different approaches to finding the day itself, which works splendidly themselves. The problem is, when I try putting them into my script I always get the error code `./test.sh: line 13: [: 29: integer expression expected`. This is my code: ``` #!/bin/bash LASTSAT=$(ncal | grep Sa | awk '{print$(NF-0)}') SATURDAY="6" DAY=$(date +"%u") DATE=$(date +"%d") echo "$DAY" echo "$DATE" echo "$LASTSAT" if [ $DATE -eq $LASTSAT ] then echo "sista lördagen..." fi ``` I got the tip to change the if statements to `[ "$DATE" = "$LASTSAT" ]` which erased the error itself, but the script will somehow not equal 27 to 27 (to take this month as an example). I also tried another approach to finding the last Saturday which was `LASTSAT=$(cal|awk '{if(NF==7){SAT=$7}};END{print SAT}')`, but it returns the exact same error if I use -eq and doesn't equal 27 to 27 using " with = I'm very confused and out of ideas and…

Accepted Answer

During testing I changed the target day and some of the variable names, but the following script works, for the next-to-last Sunday of the month. The critical change, relative to your script, was adding the `-h` switch to `ncal`, to turn off highlighting of the current day. The highlighting characters apparently come through when `awk` prints the field, but aren't visible when you do the `echo`s. Note, you can drop the `grep` after `ncal` via an `awk` match.

```
#!/bin/bash

DoDay=$(ncal -h |awk '/Su/ {print $(NF-1)}')
Datum=$(date +%d)
echo $Datum Datum
echo $DoDay DoDay

if [[ $Datum == $DoDay ]]
then
    echo "sista lördagen..."
else
    echo "doh"
fi
```

Find the last Saturday of the month in a bash script

Solution

Problem