Create a file if it does not exist when a script runs

Question

I have a shell script I run using automator that puts on the clipboard a string like Page 001, Page 002 and so forth incrementing the number 00x everytime it runs. I use it when I need to sequentially name files when doing things like scanning documents and so forth.
Presently, I have to manually create a file "~/counter" and enter the integer to start counting from. So if ~/counter contains 0, pbcopy places "Page 001" on the clipboard and so forth
The shell script
<pre class="jive-pre">
#!/usr/bin/env bash
myvar=$(cat ~/counter);
let myvar=$myvar+1;
mycopy=$(printf "Page %03d" $myvar);
echo "$mycopy" | pbcopy;
echo "$myvar" > ~/counter;
</pre>
works fine now.
I want to modify the script so that if ~/counter does not exist, the script creates a file and initializes an integer value say 1 in the file. If the file exists, the script uses the integer used in the file.
How can I get this done?

Answer 1

And because I can not leave "Well Enough Alone"
#!/usr/bin/env bash
count=0
[[ -r ~/counter ]] && read count anyjunk_aftercount <~/counter
count=$((count+1))
echo "$count" >~/counter
printf "Page %03d" $count | pbcopy
The anyjunk_aftercount is just in case something else gets into ~/counter. Assuming the first non-blank field on line 1 is the count, then anything following the count will be stuffed into anyjunk_aftercount and since the script ignores it, it will go away when the script re-writes ~/counter with just $count