Check and verify md5/sha1/sha256 checksums for MacOS X when I download files

To check the checksum of a file on a Mac, you can use the openssl command in the terminal. Here is an example of how to check the SHA256 checksum of a file:

1. Open the terminal. You can do this by searching for "Terminal" in the spotlight search (command + space) or by navigating to Applications > Utilities > Terminal.

2. Use the openssl command to compute the checksum of the file. For example, to check the SHA256 checksum of a file called example.dmg, you would enter the following command:

openssl sha256 example.dmg

3. Compare the checksum output by the openssl command with the checksum provided by the source of the file. If the checksums match, then the file has been downloaded successfully and has not been modified.

You can also use the shasum command to compute the checksum of a file. To compute the SHA256 checksum with shasum, use the following command:

shasum -a 256 example.dmg

You can replace 256 with 1 or 224 to compute the SHA1 or SHA224 checksum, respectively. You can also replace sha with md5 to compute the MD5 checksum.