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 DIFFSTAT(1)                                                     DIFFSTAT(1)




 NAME
      diffstat - make histogram from diff-output

 SYNOPSIS
      diffstat [options] [file-specifications]

 DESCRIPTION
      This program reads the output of diff and displays a histogram of the
      insertions, deletions, and modifications per-file.  Diffstat is a
      program that is useful for reviewing large, complex patch files.  It
      reads from one or more input files which contain output from diff,
      producing a histogram of the total lines changed for each file
      referenced.

      If the input filename ends with .bz2, .gz, .lzma, .z or .Z, diffstat
      will read the uncompressed data via a pipe from the corresponding
      program.  It also can infer the compression type from files piped via
      the standard input.

      Diffstat recognizes the most popular types of output from diff:

           unified
                preferred by the patch utility.

           context
                best for readability, but not very compact.

           default
                not good for much, but simple to generate.

      Diffstat detects the lines that are output by diff to tell which files
      are compared, and then counts the markers in the first column that
      denote the type of change (insertion, deletion or modification).
      These are shown in the histogram as "+", "-" and "!" characters.

      If no filename is given on the command line, diffstat reads the
      differences from the standard input.

 OPTIONS
      -b   ignore lines matching "Binary files XXX and YYY differ" in the
           diff

      -c   prefix each line of output with "#", making it a comment-line for
           shell scripts.

      -C   add SGR color escape sequences to highlight the histogram.

      -D destination
           specify a directory containing files which can be referred to as
           the result of applying the differences.  diffstat will count the
           lines in the corresponding files (after adjusting the names by



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 DIFFSTAT(1)                                                     DIFFSTAT(1)




           the -p option) to obtain the total number of lines in each file.

           The remainder, after subtracting modified and deleted lines, is
           shown as "unchanged lines".

      -e file
           redirect standard error to file.

      -f format
           specify the format of the histogram.

           0  for concise, which shows only the value and a single histogram
              code for each of insert (+), delete (-) or modify (!)

           1  for normal output,

           2  to fill in the histogram with dots,

           4  to print each value with the histogram.

           Any nonzero value gives a histogram.  The dots and individual
           values can be combined, e.g., -f6 gives both.

      -h   prints the usage message and exits.

      -k   suppress the merging of filenames in the report.

      -l   lists only the filenames.  No histogram is generated.

      -m   merge insert/delete counts from each "chunk" of the patch file to
           approximate a count of the modified lines.

      -n number
           specify the minimum width used for filenames.  If you do not
           specify this, diffstat uses the length of the longest filename,
           after stripping common prefixes.

      -N number
           specify the maximum width used for filenames.  Names longer than
           this limit are truncated on the left.  If you do not specify
           this, diffstat next checks the -n option.

      -o file
           redirect standard output to file.

      -p number
           override the logic that strips common pathnames, simulating the
           patch "-p" option.

      -q   suppress the "0 files changed" message for empty diffs.




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 DIFFSTAT(1)                                                     DIFFSTAT(1)




      -r  code
           provides optional rounding of the data shown in histogram, rather
           than truncating with error adjustments.

           0  is the default.  No rounding is performed, but accumulated
              errors are added to following columns.

           1  rounds the data

           2  rounds the data and adjusts the histogram to ensure that it
              displays something if there are any differences even if those
              would normally be rounded to zero.

      -s   show only the summary line, e.g., number of insertions and
           deletions.

      -S source
           this is like the -D option, but specifies a location where the
           original files (before applying differences) can be found.

      -t   overrides the histogram, generates output of comma separated
           values.

      -u   suppress the sorting of filenames in the report.

      -v   show progress, e.g., if the output is redirected to a file, write
           progress messages to the standard error.

      -V   prints the current version number and exits.

      -w number
           specify the maximum width of the histogram.  The histogram will
           never be shorter than 10 columns, just in case the filenames get
           too large.

 ENVIRONMENT
      Diffstat runs in a portable UNIX(Reg.) environment.

      You can override the compiled-in paths of programs used for
      decompressing input files by setting environment variables
      corresponding to their name:

           DIFFSTAT_BZCAT_PATH
           DIFFSTAT_BZIP2_PATH
           DIFFSTAT_COMPRESS_PATH
           DIFFSTAT_GZIP_PATH
           DIFFSTAT_LZCAT_PATH
           DIFFSTAT_PCAT_PATH
           DIFFSTAT_UNCOMPRESS_PATH
           DIFFSTAT_XZ_PATH
           DIFFSTAT_ZCAT_PATH



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 DIFFSTAT(1)                                                     DIFFSTAT(1)




      However, diffstat assumes that the resulting program uses the same
      command-line options, e.g., "-c" to decompress to the standard output.

 FILES
      Diffstat is a single binary module, which uses no auxiliary files.

 BUGS
      Diffstat makes a lot of assumptions about the format of a diff file.

      There is no way to obtain a filename from the standard diff between
      two files with no options.  Context diffs work, as well as unified
      diffs.

      There's no easy way to determine the degree of overlap between the
      "before" and "after" displays of modified lines.  diffstat simply
      counts the number of inserted and deleted lines to approximate
      modified lines for the -m option.

 SEE ALSO
      diff(1).

 AUTHOR
      Thomas Dickey <dickey@invisible-island.net>.































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