Originally Posted by doubledee
... is a sufficient fix to guarantee a unique, and fixed-width Photo Filename?
sha1 and any other hashing algorithm guarantee NOT unique. Billions of strings will all hash to any specific hash value. All a hash guarantees is that a SMALL change in the original value will create a different hash. Once the change gets big enough you can get the same hash again.
If you want unique then use uniqid(mt_rand())
to generate a unique value
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