NAME
    diffstat - make histogram from diff-output

USAGE
    diffstat [options] [file-specifications]

SYNOPSIS
    This program reads the output of diff and displays a histogram of the
    insertions, deletions, and modifications per-file.

DESCRIPTION
    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, .Z or .gz, diffstat
    will read the uncompressed data via a pipe.

    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 differ-
    ences from the standard input.

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

    -f format
    specify 0 for concise, 1 for normal output.

    -k   suppress the merging of filenames in the report.

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

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

    -u   suppress the sorting of filenames in the report.

    -V   prints the current version number

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

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

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's no easy way to determine the degree of  overlap between the
    "before" and "after" displays of modified lines.

SEE ALSO
    diff (1).

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