Ubuntu Manpage: ztest - check the integrity of compressed files

NAME

       ztest - check the integrity of compressed files

SYNOPSIS

       ztest [options] [files]

DESCRIPTION

ztest checks the integrity of the compressed files specified. It also warns if an uncompressed file has a
compressed file name extension, or if a compressed file has a wrong compressed extension. Uncompressed
files are otherwise ignored. If a file is specified as '-', the integrity of compressed data read from
standard input is checked. Data read from standard input must be all in the same compressed format. If a
file fails to decompress, does not exist, can't be opened, or is a terminal, ztest continues testing the
rest of the files. A final diagnostic is shown at verbosity level 1 or higher if any file fails the test
when testing multiple files.

If no files are specified, recursive searches examine the current working directory, and nonrecursive
searches read standard input.

The formats supported are bzip2, gzip, lzip, xz, and zstd.

Note that error detection in the xz format is broken. First, some xz files lack integrity information.
Second, not all xz decompressors can check the integrity of all xz files. Third, section 2.1.1.2 'Stream
Flags' of the xz format specification allows xz decompressors to produce garbage output without issuing
any warning. Therefore, xz files can't always be checked as reliably as files in the other formats can.

Exit status is 0 if all compressed files check OK, 1 if environmental problems (file not found, invalid
command-line options, I/O errors, etc), 2 if any compressed file is corrupt or invalid, or if any file
has an incorrect file name extension.

OPTIONS

       -h, --help
              display this help and exit

       -V, --version
              output version information and exit

       -M, --format=<list>
              process only the formats in <list>

       -N, --no-rcfile
              don't read runtime configuration file

       -O, --force-format=<fmt>
              force the input format

       -q, --quiet
              suppress all messages

       -r, --recursive
              operate recursively on directories

       -R, --dereference-recursive
              recursively follow symbolic links

       -v, --verbose
              be verbose (a 2nd -v gives more)

       --bz2=<command>
              set compressor and options for bzip2 format

       --gz=<command>
              set compressor and options for gzip format

       --lz=<command>
              set compressor and options for lzip format

       --xz=<command>
              set compressor and options for xz format

       --zst=<command>
              set compressor and options for zstd format

       Valid formats for options '-M' and '-O' are 'bz2', 'gz', 'lz', 'xz', and 'zst'.

REPORTING BUGS

       Report bugs to zutils-bug@nongnu.org
       Zutils home page: http://www.nongnu.org/zutils/zutils.html

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