How To: File Checksum
In the past I have downloaded jquery, a javascript library, from google that I like to use when building different websites. When you go to download the file, it gives you a checksum, or value of numbers and letters, that is used to verify the integrity of a file. Usually I dont pay any attention to the checksum value because I am never too worried about it not downloading correctly but mainly because I didnt know how to use a checksum.
A quick google search turned up step by step instructions on how to verify the checksum on a Mac computer. Here is the link: http://www.bresink.de/osx/sha1.html.
Since I am running OS X.4 all of my downloads go staight to my desktop so used a slightly different process.
- Open Terminal
- Change to your Desktop (Only if file to check is on desktop) (cd Desktop)
- Type the following command (openssl sha1 filenamehere)
Thats all there is to it. There are a couple things you should note. First of all this is for an sha1 checksum. Usually if you download a file that has a checksum, it should be listed with the file what the encryption type used is. If it is different than sha1 you would just need to change it in step 3 to the specified encryption. Also, if your file is not located on the desktop, then like the steps in the link, you can just drag and drop into the terminal window.
