![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to diff.1 CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / man / man1|
Return to diff.1 CVS log | Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / man / man1 |
1.1 root 1: .TH DIFF 1 "18 January 1983"
2: .UC 4
3: .SH NAME
4: diff \- differential file and directory comparator
5: .SH SYNOPSIS
6: .B diff
7: [
8: .B \-l
9: ] [
10: .B \-r
11: ] [
12: .B \-s
13: ] [
14: \fB\-cefh\fR
15: ] [
16: .B \-b
17: ] dir1 dir2
18: .br
19: .B diff
20: [
21: \fB\-cefh
22: ] [
23: \fB\-b\fR
24: ] file1 file2
25: .br
26: .B diff
27: [
28: .BI \-D string
29: ] [
30: .B \-b
31: ]
32: file1 file2
33: .SH DESCRIPTION
34: If both arguments are directories,
35: .I diff
36: sorts the contents of the directories by name, and then runs the
37: regular file
38: .I diff
39: algorithm (described below)
40: on text files which are different.
41: Binary files which differ,
42: common subdirectories, and files which appear in only one directory
43: are listed.
44: Options when comparing directories are:
45: .TP
46: .B \-l
47: long output format; each text file
48: .I diff
49: is piped through
50: .IR pr (1)
51: to paginate it,
52: other differences are remembered and summarized
53: after all text file differences are reported.
54: .TP
55: .B \-r
56: causes application of
57: .I diff
58: recursively to common subdirectories encountered.
59: .TP
60: .B \-s
61: causes
62: .I diff
63: to report files which are the same, which are otherwise not mentioned.
64: .TP
65: .B \-Sname
66: starts a directory
67: .I diff
68: in the middle beginning with file
69: .I name.
70: .PP
71: When run on regular files, and when comparing text files which differ
72: during directory comparison,
73: .I diff
74: tells what lines must be changed in the files to bring them into agreement.
75: Except in rare circumstances,
76: .I diff
77: finds a smallest sufficient set of file differences.
78: If neither
79: .I file1
80: nor
81: .I file2
82: is a directory, then either
83: may be given as `\-', in which case the standard input is used.
84: If
85: .I file1
86: is a directory,
87: then a file in that directory whose file-name is the same as the file-name of
88: .I file2
89: is used (and vice versa).
90: .PP
91: There are several options for output format;
92: the default output format contains lines of these forms:
93: .IP "" 5
94: .I n1
95: a
96: .I n3,n4
97: .br
98: .I n1,n2
99: d
100: .I n3
101: .br
102: .I n1,n2
103: c
104: .I n3,n4
105: .PP
106: These lines resemble
107: .I ed
108: commands to convert
109: .I file1
110: into
111: .IR file2 .
112: The numbers after the letters pertain to
113: .IR file2 .
114: In fact, by exchanging `a' for `d' and reading backward
115: one may ascertain equally how to convert
116: .I file2
117: into
118: .IR file1 .
119: As in
120: .I ed,
121: identical pairs where
122: .I n1
123: =
124: .I n2
125: or
126: .I n3
127: =
128: .I n4
129: are abbreviated as a single number.
130: .PP
131: Following each of these lines come all the lines that are
132: affected in the first file flagged by `<',
133: then all the lines that are affected in the second file
134: flagged by `>'.
135: .PP
136: Except for
137: .B \-b,
138: which may be given with any of the others,
139: the following options are mutually exclusive:
140: .TP 9
141: .B \-e
142: producing a script of
143: .I "a, c"
144: and
145: .I d
146: commands for the editor
147: .I ed,
148: which will recreate
149: .I file2
150: from
151: .IR file1 .
152: In connection with
153: .BR \-e ,
154: the following shell program may help maintain
155: multiple versions of a file.
156: Only an ancestral file ($1) and a chain of
157: version-to-version
158: .I ed
159: scripts ($2,$3,...) made by
160: .I diff
161: need be on hand.
162: A `latest version' appears on
163: the standard output.
164: .IP
165: \ \ \ \ \ \ \ \ (shift; cat $*; echo \'1,$p\') \(bv ed \- $1
166: .IP
167: Extra commands are added to the output when comparing directories with
168: .B \-e,
169: so that the result is a
170: .IR sh (1)
171: script for converting text files which are common to the two directories
172: from their state in
173: .I dir1
174: to their state in
175: .I dir2.
176: .TP 9
177: .B \-f
178: produces a script similar to that of
179: .B \-e,
180: not useful with
181: .I ed,
182: and in the opposite order.
183: .TP 9
184: .B \-c
185: produces a diff with lines of context.
186: The default is to present 3 lines of context and may be changed, e.g to 10, by
187: .BR \-c10 \&.
188: With
189: .B \-c
190: the output format is modified slightly:
191: the output beginning with identification of the files involved and
192: their creation dates and then each change is separated
193: by a line with a dozen *'s.
194: The lines removed from
195: .I file1
196: are marked with `\(mi'; those added to
197: .I file2
198: are marked `+'. Lines which are changed from one
199: file to the other are marked in both files with `!'.
200: .TP 9
201: .B \-h
202: does a fast, half-hearted job.
203: It works only when changed stretches are short
204: and well separated,
205: but does work on files of unlimited length.
206: .TP
207: .B \-Dstring
208: causes
209: .I diff
210: to create a merged version of
211: .I file1
212: and
213: .I file2
214: on the standard output, with C preprocessor controls included so that
215: a compilation of the result without defining \fIstring\fR is equivalent
216: to compiling
217: .I file1,
218: while defining
219: .I string
220: will yield
221: .I file2.
222: .TP
223: .B \-b
224: causes trailing blanks (spaces and tabs) to be ignored, and other
225: strings of blanks to compare equal.
226: .SH FILES
227: /tmp/d?????
228: .br
229: /usr/lib/diffh for
230: .B \-h
231: .br
232: /bin/pr
233: .SH "SEE ALSO"
234: cmp(1), cc(1), comm(1), ed(1), diff3(1)
235: .SH DIAGNOSTICS
236: Exit status is 0 for no differences, 1 for some, 2 for trouble.
237: .SH BUGS
238: Editing scripts produced under the
239: .BR \-e " or"
240: .BR \-f " option are naive about"
241: creating lines consisting of a single `\fB.\fR'.
242: .PP
243: When comparing directories with the
244: .B \-b
245: option specified,
246: .I diff
247: first compares the files ala
248: .I cmp,
249: and then decides to run the
250: .I diff
251: algorithm if they are not equal.
252: This may cause a small amount of spurious output if the files
253: then turn out to be identical because the only differences are
254: insignificant blank string differences.
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.