sum invocation (GNU Coreutils 9.0)
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6.2 sum: Print checksum and block counts
sum
computes a 16-bit checksum for each given file
, or standard input if none are given or for a file
of ‘-
’. Synopsis:
sum [option]… [file]…
sum
prints the checksum for each file
followed by the number of blocks in the file (rounded up). If at least one file
is given, file names are also printed.
By default, GNU sum
computes checksums using an algorithm compatible with BSD sum
and prints file sizes in units of 1024-byte blocks.
The program accepts the following options. Also see Common options.
- ‘
-r
’ Use the default (BSD compatible) algorithm. This option is included for compatibility with the System V
sum
. Unless-s
was also given, it has no effect.- ‘
-s
’
‘--sysv
’ Compute checksums using an algorithm compatible with System V
sum
’s default, and print file sizes in units of 512-byte blocks.
sum
is provided for compatibility; the cksum
program (see next section) is preferable in new applications.
An exit status of zero indicates success, and a nonzero value indicates failure.