shasum

Shasum is a command line tool used for generating and verifying checksums of files using various hash algorithms. The primary purpose of shasum is to ensure the integrity and authenticity of files by comparing the checksums before and after any data transfer or storage. It supports several widely used hash algorithms such as SHA-1, SHA-256, SHA-512, and MD5, among others. By default, shasum calculates the SHA-1 hash of a file, but this can be changed using command-line options. The output of shasum is a checksum hash, typically represented as a hexadecimal string. To verify the integrity of a file, the generated checksum can be compared with the original checksum. If the checksums match, it indicates that the file has not been altered or corrupted during the transfer or storage process. Shasum is widely used in the software distribution industry to ensure the authenticity and integrity of downloaded files. It is often included in security protocols and software verification processes. Shasum is available as a command-line tool on Unix-like operating systems, including macOS and Linux.