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.
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 -D destination
50 specify a directory containing files which can be referred to as
51 the result of applying the differences. diffstat will count the
52 lines in the corresponding files (after adjusting the names by
53 the -p option) to obtain the total number of lines in each file.
54 The remainder, after subtracting modified and deleted lines, is
56 shown as "unchanged lines".
57 -e file
59 redirect standard error to file.
60 -f format
62 specify the format of the histogram.
63 0 for concise, which shows only the value and a single his‐
65 togram code for each of insert (+), delete (-) or modify (!)
66 1 for normal output,
68 2 to fill in the histogram with dots,
70 4 to print each value with the histogram.
72 Any nonzero value gives a histogram. The dots and individual
74 values can be combined, e.g., -f6 gives both.
75 -h prints the usage message and exits.
77 -k suppress the merging of filenames in the report.
79 -l lists only the filenames. No histogram is generated.
81 -m merge insert/delete counts from each "chunk" of the patch file
83 to approximate a count of the modified lines.
84 -n number
86 specify the minimum width used for filenames. If you do not
87 specify this, diffstat uses the length of the longest filename,
88 after stripping common prefixes.
89 -N number
91 specify the maximum width used for filenames. Names longer than
92 this limit are truncated on the left. If you do not specify
93 this, diffstat next checks the -n option.
94 -o file
96 redirect standard output to file.
97 -p number
99 override the logic that strips common pathnames, simulating the
100 patch "-p" option.
101 -q suppress the "0 files changed" message for empty diffs.
103 -r code
105 provides optional rounding of the data shown in histogram,
106 rather than truncating with error adjustments.
107 0 is the default. No rounding is performed, but accumulated
109 errors are added to following columns.
110 1 rounds the data
112 2 rounds the data and adjusts the histogram to ensure that it
114 displays something if there are any differences even if those
115 would normally be rounded to zero.
116 -S source
118 this is like the -D option, but specifies a location where the
119 original files (before applying differences) can be found.
120 -t overrides the histogram, generates output of comma separated
122 values.
123 -u suppress the sorting of filenames in the report.
125 -v show progress, e.g., if the output is redirected to a file,
127 write progress messages to the standard error.
128 -V prints the current version number and exits.
130 -w number
132 specify the maximum width of the histogram. The histogram will
133 never be shorter than 10 columns, just in case the filenames get
134 too large.
135
137 Diffstat runs in a portable UNIX® environment.
138 You can override the compiled-in paths of programs used for decompress‐
140 ing input files by setting environment variables corresponding to their
141 name:
142 DIFFSTAT_BZCAT_PATH
144 DIFFSTAT_BZIP2_PATH
145 DIFFSTAT_COMPRESS_PATH
146 DIFFSTAT_GZIP_PATH
147 DIFFSTAT_LZCAT_PATH
148 DIFFSTAT_PCAT_PATH
149 DIFFSTAT_UNCOMPRESS_PATH
150 DIFFSTAT_ZCAT_PATH
151 However, diffstat assumes that the resulting program uses the same com‐
153 mand-line options, e.g., "-c" to decompress to the standard output.
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156 Diffstat is a single binary module, which uses no auxiliary files.
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159 Diffstat makes a lot of assumptions about the format of a diff file.
160 There is no way to obtain a filename from the standard diff between two
162 files with no options. Context diffs work, as well as unified diffs.
163 There's no easy way to determine the degree of overlap between the
165 "before" and "after" displays of modified lines. diffstat simply
166 counts the number of inserted and deleted lines to approximate modified
167 lines for the -m option.
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170 diff (1).
171
173 Thomas Dickey <dickey@invisible-island.net>.
174 DIFFSTAT(1)