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       diffstat - make histogram from diff-output


       diffstat [options] [file-specifications]


       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

       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:

                     preferred by the patch utility.

                     best for readability, but not very compact.

                     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.


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

       -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
              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.

       -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

       -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

       -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.


       Diffstat runs in a portable UNIX® environment.

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


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


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


       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.


       diff (1).


       Thomas Dickey <>.