NAME

       zdiff - decompress and compare two files line by line

SYNOPSIS

       zdiff [options] file1 [file2]

DESCRIPTION

       zdiff  compares  two  files and, if they differ, writes to standard output the differences
       line by line. A hyphen '-' used as a file argument means standard input. If any file given
       is compressed, its decompressed content is used.  zdiff is a front end to the program diff
       and has the limitation that messages from diff refer to temporary file  names  instead  of
       those specified.

       'zdiff -v -V' prints the version of the diff program used.

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

       zdiff compares file1 to file2. The standard input is used only if file1 or file2 refers to
       standard input. If file2 is omitted zdiff tries the following:

              - If file1 is compressed, compares its decompressed contents with the corresponding
              uncompressed file (the name of file1 with the extension removed).

              -  If  file1  is  uncompressed,  compares  it  with  the  decompressed  contents of
              file1.[lz|bz2|gz|zst|xz] (the first one that is found).

       Exit status is 0 if inputs are identical, 1 if different, 2 if trouble.  Some options only
       work if the diff program used supports them.

OPTIONS

       -h, --help
              display this help and exit

       -V, --version
              output version information and exit

       -a, --text
              treat all files as text

       -b, --ignore-space-change
              ignore changes in the amount of white space

       -B, --ignore-blank-lines
              ignore changes whose lines are all blank

       -c     use the context output format

       -C, --context=<n>
              same as -c but use <n> lines of context

       -d, --minimal
              try hard to find a smaller set of changes

       -E, --ignore-tab-expansion
              ignore changes due to tab expansion

       -i, --ignore-case
              ignore case differences in file contents

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

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

       -O, --force-format=[<f1>][,<f2>]
              force one or both input formats

       -p, --show-c-function
              show which C function each change is in

       -q, --brief
              output only whether files differ

       -s, --report-identical-files
              report when two files are identical

       -t, --expand-tabs
              expand tabs to spaces in output

       -T, --initial-tab
              make tabs line up by prepending a tab

       -u     use the unified output format

       -U, --unified=<n>
              same as -u but use <n> lines of context

       -v, --verbose
              verbose mode (for --version)

       -w, --ignore-all-space
              ignore all white space

       -W, --width=<n>
              output at most <n> print columns (for -y)

       -y, --side-by-side
              output in two columns

       --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', 'zst', and 'un' for
       uncompressed.

REPORTING BUGS

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

COPYRIGHT

       Copyright © 2023  Antonio  Diaz  Diaz.   License  GPLv2+:  GNU  GPL  version  2  or  later
       <http://gnu.org/licenses/gpl.html>
       This  is free software: you are free to change and redistribute it.  There is NO WARRANTY,
       to the extent permitted by law.

SEE ALSO

       The full documentation for zdiff is maintained as a Texinfo manual.  If the info and zdiff
       programs are properly installed at your site, the command

              info zutils

       should give you access to the complete manual.