| sum, md5sum, sha1sum \- sum and count blocks in a file |

| calculates and prints a 32-bit hexadecimal checksum, |

| The checksum is also a function of the input length. |

| Other summing algorithms are available. |

| Sum with the algorithm of System V's |

| and print the length (in 1K blocks) of the input. |

| Sum with System V's default algorithm |

| and print the length (in 512-byte blocks) of the input. |

| is typically used to look for bad spots, |

| to validate a file communicated over |

| some transmission line or |

| as a quick way to determine if two files on different machines might be the same. |

| computes the 32 hex digit RSA Data Security, Inc. MD5 Message-Digest Algorithm |

| computes the 40 hex digit National Institute of Standards and Technology SHA1 secure hash algorithm |

| described in FIPS PUB 180-1. |