1DIFFSTAT(1) General Commands Manual DIFFSTAT(1)
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6 diffstat - make histogram from diff-output
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9 diffstat [options] [file-specifications]
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12 This program reads the output of diff and displays a histogram of the
13 insertions, deletions, and modifications per-file. Diffstat is a pro‐
14 gram that is useful for reviewing large, complex patch files. It reads
15 from one or more input files which contain output from diff, producing
16 a histogram of the total lines changed for each file referenced.
17 If the input filename ends with “.bz2”, “.gz”, “.lzma”, “.xz”, “.z” or
19 “.Z”, diffstat will read the uncompressed data via a pipe from the cor‐
20 responding program. It also can infer the compression type from files
21 piped via the standard input.
22 Diffstat recognizes the most popular types of output from diff:
24 unified
26 preferred by the patch utility.
27 context
29 best for readability, but not very compact.
30 default
32 not good for much, but simple to generate.
33 Diffstat detects the lines that are output by diff to tell which files
35 are compared, and then counts the markers in the first column that de‐
36 note the type of change (insertion, deletion or modification). These
37 are shown in the histogram as "+", "-" and "!" characters.
38 If no filename is given on the command line, diffstat reads the differ‐
40 ences from the standard input.
41
43 -b ignore lines matching "Binary files XXX and YYY differ" in the
44 diff
45 -c prefix each line of output with "#", making it a comment-line
47 for shell scripts.
48 -C add SGR color escape sequences to highlight the histogram.
50 -D destination
52 specify a directory containing files which can be referred to as
53 the result of applying the differences. diffstat will count the
54 lines in the corresponding files (after adjusting the names by
55 the -p option) to obtain the total number of lines in each file.
56 The remainder, after subtracting modified and deleted lines, is
58 shown as "unchanged lines".
59 -d The debug prints a lot of information. It is normally compiled-
61 in, but can be suppressed.
62 -e file
64 redirect standard error to file.
65 -E strip out ANSI escape sequences on each line before parsing the
67 differences. This allows diffstat to be used with colordiff.
68 -f format
70 specify the format of the histogram.
71 0 for concise, which shows only the value and a single his‐
73 togram code for each of insert (+), delete (-) or modify (!)
74 1 for normal output,
76 2 to fill in the histogram with dots,
78 4 to print each value with the histogram.
80 Any nonzero value gives a histogram. The dots and individual
82 values can be combined, e.g., -f6 gives both.
83 -h prints the usage message and exits.
85 -k suppress the merging of filenames in the report.
87 -K attempt to improve the annotation of "only" files by looking for
89 a match in the resulting set of files and inferring whether the
90 file was added or removed.
91 This does not currently work in combination with -R because
93 diffstat maintains only the resulting set of files.
94 -l lists only the filenames. No histogram is generated.
96 -m merge insert/delete counts from each "chunk" of the patch file
98 to approximate a count of the modified lines.
99 -n number
101 specify the minimum width used for filenames. If you do not
102 specify this, diffstat uses the length of the longest filename,
103 after stripping common prefixes.
104 -N number
106 specify the maximum width used for filenames. Names longer than
107 this limit are truncated on the left. If you do not specify
108 this, diffstat next checks the -n option.
109 -o file
111 redirect standard output to file.
112 -p number
114 override the logic that strips common pathnames, simulating the
115 patch "-p" option.
116 If you do not give a -p option, diffstat examines the differ‐
118 ences and strips the common prefix from the pathnames. This is
119 not what patch does.
120 -q suppress the "0 files changed" message for empty diffs.
122 -r code
124 provides optional rounding of the data shown in histogram,
125 rather than truncating with error adjustments.
126 0 is the default. No rounding is performed, but accumulated
128 errors are added to following columns.
129 1 rounds the data
131 2 rounds the data and adjusts the histogram to ensure that it
133 displays something if there are any differences even if those
134 would normally be rounded to zero.
135 -R Assume patch was created with old and new files swapped.
137 -s show only the summary line, e.g., number of insertions and dele‐
139 tions.
140 -S source
142 this is like the -D option, but specifies a location where the
143 original files (before applying differences) can be found.
144 -t overrides the histogram, generates output of comma separated
146 values for the number of changed lines found in the differences
147 for each file: inserted, deleted and modified.
148 If -S or -D options are given, the number of unchanged lines
150 precedes the number of changes.
151 -T prints the numbers that the -t option would show, between the
153 pathname and histogram.
154 The width of the number of changes is determined by the largest
156 value (but at least 3). The width given in the -w option is
157 separate from the width of these numbers.
158 -u suppress the sorting of filenames in the report.
160 -v show progress, e.g., if the output is redirected to a file,
162 write progress messages to the standard error.
163 -V prints the current version number and exits.
165 -w number
167 specify the maximum width of the histogram. The histogram will
168 never be shorter than 10 columns, just in case the filenames get
169 too large.
170 The default is 80 columns, unless the output is to a terminal.
172 In that case, the default width is the terminal's width.
173
175 Diffstat runs in a POSIX environment.
176 You can override the compiled-in paths of programs used for decompress‐
178 ing input files by setting environment variables corresponding to their
179 name:
180 DIFFSTAT_BZCAT_PATH
182 DIFFSTAT_BZIP2_PATH
183 DIFFSTAT_COMPRESS_PATH
184 DIFFSTAT_GZIP_PATH
185 DIFFSTAT_LZCAT_PATH
186 DIFFSTAT_PCAT_PATH
187 DIFFSTAT_UNCOMPRESS_PATH
188 DIFFSTAT_XZ_PATH
189 DIFFSTAT_ZCAT_PATH
190 However, diffstat assumes that the resulting program uses the same com‐
192 mand-line options, e.g., "-c" to decompress to the standard output.
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195 Diffstat is a single binary module, which uses no auxiliary files.
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198 Diffstat makes a lot of assumptions about the format of diff's output.
199 There is no way to obtain a filename from the standard diff between two
201 files with no options. Context diffs work, as well as unified diffs.
202 There's no easy way to determine the degree of overlap between the "be‐
204 fore" and "after" displays of modified lines. diffstat simply counts
205 the number of inserted and deleted lines to approximate modified lines
206 for the -m option.
207
209 diff(1), patch(1).
210
212 Thomas Dickey <dickey@invisible-island.net>.
213 DIFFSTAT(1)