diffstat.1   [plain text]


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.\" $Id: diffstat.1,v 1.18 2005/08/15 23:55:59 tom Exp $
.TH DIFFSTAT 1
.SH NAME
\fBdiffstat\fP \- make histogram from diff-output
.SH SYNOPSIS
\fBdiffstat\fP\fI [options] [file-specifications]\fP
.SH DESCRIPTION
This program reads the output of \fBdiff\fP 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 \fBdiff\fP,
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.
.PP
Diffstat recognizes the most popular types of output from diff:
.RS
.TP
unified
preferred by the \fBpatch\fP utility.
.TP
context
best for readability, but not very compact.
.TP
default
not good for much, but simple to generate.
.RE
.PP
\fBDiffstat\fP detects the lines that are output by \fBdiff\fP 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.
.PP
If no filename is given on the command line,
\fBdiffstat\fP reads the differences from the standard input.
.SH OPTIONS
.TP
.B -c
prefix each line of output with "#", making it a comment-line for shell
scripts.
.TP
.BI -e " file"
redirect standard error to \fIfile\fR.
.TP
.BI -f " format"
specify the format of the histogram.
.RS
.TP 3
0
for concise, which shows only the value and a single histogram code for each of
insert (+),
delete (-) or
modify (!)
.TP 3
1
for normal output,
.TP 3
2
to fill in the histogram with dots,
.TP 3
4
to print each value with the histogram.
.RE
.IP
Any nonzero value gives a histogram.
The dots and individual values can be combined,
e.g., \fB-f6\fP gives both.
.TP
.B -h
prints the usage message and exits.
.TP
.B -k
suppress the merging of filenames in the report.
.TP
.B -l
lists only the filenames.
No histogram is generated.
.TP
.BI -n " number"
specify the minimum width used for filenames.
If you don't specify this, \fBdiffstat\fP uses the length of the longest
filename, after stripping common prefixes.
.TP
.BI -o " file"
redirect standard output to \fIfile\fR.
.TP
.BI -p " number"
override the logic that strips common pathnames, simulating the \fBpatch\fP
"-p" option.
.TP
.B -r " code"
provides optional rounding of the data shown in histogram,
rather than truncating with error adjustments.
.RS
.TP 3
0
is the default.
No rounding is performed,
but accumulated errors are added to following columns.
.TP 3
1
rounds the data
.TP 3
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.
.RE
.TP
.B -t
overrides the histogram,
generates output of comma separated values.
.TP
.B -u
suppress the sorting of filenames in the report.
.TP
.B -v
show progress,
e.g., if the output is redirected to a file,
write progress messages to the standard error.
.TP
.B -V
prints the current version number and exits.
.TP
.BI -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.
.SH ENVIRONMENT
.PP
\fBDiffstat\fP runs in a portable UNIX\*R environment.
.SH FILES
.PP
\fBDiffstat\fP is a single binary module, which uses no auxiliary files.
.SH BUGS
.PP
\fBDiffstat\fP makes a lot of assumptions about the format of a \fBdiff\fP file.
.PP
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.
.PP
There's no easy way to determine the degree of overlap between the
"before" and "after" displays of modified lines.
.SH SEE ALSO
.PP
diff (1).
.SH AUTHOR
.PP
Thomas Dickey <dickey@invisible-island.net>.