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 pro-
gram 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 from the corresponding program.
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.
-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 his-
togram 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.
-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.
-o file
redirect standard output to file.
-p number
override the logic that strips common pathnames, simulating the
patch "-p" option.
-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.
-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® 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 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.
SEE ALSO
diff (1).
AUTHOR
Thomas Dickey <dickey@invisible-island.net>.
DIFFSTAT(1)
