This option is not supported by the cksum command,
as it operates in binary mode exclusively.
Treat each input file as binary, by reading it in binary mode and
outputting a ‘*’ flag. This is the inverse of --text.
On systems like GNU that do not distinguish between binary
and text files, this option merely flags each input mode as binary:
the checksum is unaffected. This option is the default on systems
like MS-DOS that distinguish between binary and text files, except
for reading standard input when standard input is a terminal.
Read file names and checksum information (not data) from each file (or from standard input if no file was specified) and report whether the checksums match the contents of the named files. The input to this mode is usually the output of a prior, checksum-generating run of the command.
Three input formats are supported. Either the default output format described above, the --tag output format, or the BSD reversed mode format which is similar to the default mode, but doesn’t use a character to distinguish binary and text modes.
For the cksum command, the --check option
supports auto-detecting the digest algorithm to use,
when presented with checksum information in the --tag output format.
Also for the cksum command, the --check option
auto-detects the digest encoding, accepting both standard hexadecimal
checksums and those generated via cksum with its
--base64 option.
Output with --zero enabled is not supported by --check.
For each such line, cksum reads the named file and computes its
checksum. Then, if the computed message digest does not match the
one on the line with the file name, the file is noted as having
failed the test. Otherwise, the file passes the test.
By default, for each valid line, one line is written to standard
output indicating whether the named file passed the test.
After all checks have been performed, if there were any failures,
a warning is issued to standard error.
Use the --status option to inhibit that output.
If any listed file cannot be opened or read, if any valid line has
a checksum inconsistent with the associated file, or if no valid
line is found, cksum exits with nonzero status. Otherwise,
it exits successfully.
The cksum command does not support --check
with the older ‘sysv’, ‘bsd’, or ‘crc’ algorithms.
This option is useful only when verifying checksums. When verifying checksums, don’t fail or report any status for missing files. This is useful when verifying a subset of downloaded files given a larger list of checksums.
This option is useful only when verifying checksums. When verifying checksums, don’t generate an ’OK’ message per successfully checked file. Files that fail the verification are reported in the default one-line-per-file format. If there is any checksum mismatch, print a warning summarizing the failures to standard error.
This option is useful only when verifying checksums. When verifying checksums, don’t generate the default one-line-per-file diagnostic and don’t output the warning summarizing any failures. Failures to open or read a file still evoke individual diagnostics to standard error. If all listed files are readable and are consistent with the associated checksums, exit successfully. Otherwise exit with a status code indicating there was a failure.
Output BSD style checksums, which indicate the checksum algorithm used.
As a GNU extension, if --zero is not used, file names with problematic
characters are escaped as described above, using the same escaping indicator of
‘\’ at the start of the line, as used with the other output format.
The --tag option implies binary mode, and is disallowed with
--text mode as supporting that would unnecessarily complicate
the output format, while providing little benefit.
See cksum output modes for details of this format.
The cksum command, uses --tag as its default output format.
This option is not supported by the cksum command.
Treat each input file as text, by reading it in text mode and
outputting a ‘ ’ flag. This is the inverse of --binary.
This option is the default on systems like GNU that do not
distinguish between binary and text files. On other systems, it is
the default for reading standard input when standard input is a
terminal. This mode is never defaulted to if --tag is used.
When verifying checksums, warn about improperly formatted checksum lines. This option is useful only if all but a few lines in the checked input are valid.
When verifying checksums, if one or more input line is invalid, exit nonzero after all warnings have been issued.
Output a zero byte (ASCII NUL) at the end of each line, rather than a newline. This option enables other programs to parse the output even when that output would contain data with embedded newlines. Also file name escaping is not used.