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, .z or .Z, diffstat
19 will read the uncompressed data via a pipe from the corresponding pro‐
20 gram. It also can infer the compression type from files piped via the
21 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
36 denote 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.
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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 -f format
67 specify the format of the histogram.
68 0 for concise, which shows only the value and a single his‐
70 togram code for each of insert (+), delete (-) or modify (!)
71 1 for normal output,
73 2 to fill in the histogram with dots,
75 4 to print each value with the histogram.
77 Any nonzero value gives a histogram. The dots and individual
79 values can be combined, e.g., -f6 gives both.
80 -h prints the usage message and exits.
82 -k suppress the merging of filenames in the report.
84 -K attempt to improve the annotation of "only" files by looking for
86 a match in the resulting set of files and inferring whether the
87 file was added or removed.
88 This does not currently work in combination with -R because
90 diffstat maintains only the resulting set of files.
91 -l lists only the filenames. No histogram is generated.
93 -m merge insert/delete counts from each "chunk" of the patch file
95 to approximate a count of the modified lines.
96 -n number
98 specify the minimum width used for filenames. If you do not
99 specify this, diffstat uses the length of the longest filename,
100 after stripping common prefixes.
101 -N number
103 specify the maximum width used for filenames. Names longer than
104 this limit are truncated on the left. If you do not specify
105 this, diffstat next checks the -n option.
106 -o file
108 redirect standard output to file.
109 -p number
111 override the logic that strips common pathnames, simulating the
112 patch "-p" option.
113 -q suppress the "0 files changed" message for empty diffs.
115 -r code
117 provides optional rounding of the data shown in histogram,
118 rather than truncating with error adjustments.
119 0 is the default. No rounding is performed, but accumulated
121 errors are added to following columns.
122 1 rounds the data
124 2 rounds the data and adjusts the histogram to ensure that it
126 displays something if there are any differences even if those
127 would normally be rounded to zero.
128 -R Assume patch was created with old and new files swapped.
130 -s show only the summary line, e.g., number of insertions and dele‐
132 tions.
133 -S source
135 this is like the -D option, but specifies a location where the
136 original files (before applying differences) can be found.
137 -t overrides the histogram, generates output of comma separated
139 values.
140 -u suppress the sorting of filenames in the report.
142 -v show progress, e.g., if the output is redirected to a file,
144 write progress messages to the standard error.
145 -V prints the current version number and exits.
147 -w number
149 specify the maximum width of the histogram. The histogram will
150 never be shorter than 10 columns, just in case the filenames get
151 too large.
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154 Diffstat runs in a portable UNIX® environment.
155 You can override the compiled-in paths of programs used for decompress‐
157 ing input files by setting environment variables corresponding to their
158 name:
159 DIFFSTAT_BZCAT_PATH
161 DIFFSTAT_BZIP2_PATH
162 DIFFSTAT_COMPRESS_PATH
163 DIFFSTAT_GZIP_PATH
164 DIFFSTAT_LZCAT_PATH
165 DIFFSTAT_PCAT_PATH
166 DIFFSTAT_UNCOMPRESS_PATH
167 DIFFSTAT_XZ_PATH
168 DIFFSTAT_ZCAT_PATH
169 However, diffstat assumes that the resulting program uses the same com‐
171 mand-line options, e.g., "-c" to decompress to the standard output.
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174 Diffstat is a single binary module, which uses no auxiliary files.
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177 Diffstat makes a lot of assumptions about the format of a diff file.
178 There is no way to obtain a filename from the standard diff between two
180 files with no options. Context diffs work, as well as unified diffs.
181 There's no easy way to determine the degree of overlap between the
183 "before" and "after" displays of modified lines. diffstat simply
184 counts the number of inserted and deleted lines to approximate modified
185 lines for the -m option.
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188 diff(1).
189
191 Thomas Dickey <dickey@invisible-island.net>.
192 DIFFSTAT(1)