Annotation of src/usr.bin/diff/diff.1, Revision 1.44
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1.2 deraadt 30: .\" @(#)diff.1 8.1 (Berkeley) 6/30/93
31: .\"
1.44 ! millert 32: .Dd $Mdocdate: February 13 2014 $
1.1 deraadt 33: .Dt DIFF 1
1.5 jmc 34: .Os
1.1 deraadt 35: .Sh NAME
36: .Nm diff
37: .Nd differential file and directory comparator
38: .Sh SYNOPSIS
39: .Nm diff
1.44 ! millert 40: .Op Fl abdipTtw
1.6 millert 41: .Oo
1.26 otto 42: .Fl c | e | f |
1.37 sobrado 43: .Fl n | q | u
1.6 millert 44: .Oc
1.36 sobrado 45: .Op Fl I Ar pattern
1.16 millert 46: .Op Fl L Ar label
1.6 millert 47: .Ar file1 file2
48: .Nm diff
1.37 sobrado 49: .Op Fl abdilpTtw
1.26 otto 50: .Op Fl I Ar pattern
1.16 millert 51: .Op Fl L Ar label
52: .Fl C Ar number
1.6 millert 53: .Ar file1 file2
54: .Nm diff
1.37 sobrado 55: .Op Fl abdiltw
1.26 otto 56: .Op Fl I Ar pattern
1.16 millert 57: .Fl D Ar string
1.1 deraadt 58: .Ar file1 file2
59: .Nm diff
1.37 sobrado 60: .Op Fl abdilpTtw
1.26 otto 61: .Op Fl I Ar pattern
1.16 millert 62: .Op Fl L Ar label
63: .Fl U Ar number
1.1 deraadt 64: .Ar file1 file2
65: .Nm diff
1.37 sobrado 66: .Op Fl abdilNPprsTtw
1.6 millert 67: .Oo
1.26 otto 68: .Fl c | e | f |
1.37 sobrado 69: .Fl n | q | u
1.6 millert 70: .Oc
1.36 sobrado 71: .Op Fl I Ar pattern
1.11 millert 72: .Bk -words
1.16 millert 73: .Op Fl L Ar label
1.6 millert 74: .Op Fl S Ar name
1.11 millert 75: .Op Fl X Ar file
76: .Op Fl x Ar pattern
77: .Ek
1.1 deraadt 78: .Ar dir1 dir2
79: .Sh DESCRIPTION
80: The
1.5 jmc 81: .Nm
1.1 deraadt 82: utility compares the contents of
83: .Ar file1
84: and
85: .Ar file2
86: and writes to the standard output the list of changes necessary to
87: convert one file into the other.
88: No output is produced if the files are identical.
89: .Pp
1.22 jmc 90: Output options (mutually exclusive):
1.2 deraadt 91: .Bl -tag -width Ds
1.31 jmc 92: .It Fl C Ar number
93: Like
94: .Fl c
95: but produces a diff with
96: .Ar number
97: lines of context.
1.2 deraadt 98: .It Fl c
1.6 millert 99: Produces a diff with 3 lines of context.
1.1 deraadt 100: With
101: .Fl c
102: the output format is modified slightly:
1.21 jmc 103: the output begins with identification of the files involved and
1.1 deraadt 104: their creation dates and then each change is separated
1.26 otto 105: by a line with fifteen
106: .Li * Ns 's .
1.1 deraadt 107: The lines removed from
108: .Ar file1
1.5 jmc 109: are marked with
1.26 otto 110: .Sq \&-\ \& ;
1.5 jmc 111: those added to
1.1 deraadt 112: .Ar file2
1.5 jmc 113: are marked
114: .Sq \+\ \& .
115: Lines which are changed from one file to the other are marked in
116: both files with
117: .Sq !\ \& .
1.19 otto 118: Changes which lie within 3 lines of each other are grouped together on
119: output.
1.31 jmc 120: .It Fl D Ar string
121: Creates a merged version of
122: .Ar file1
123: and
124: .Ar file2
125: on the standard output, with C preprocessor controls included so that
126: a compilation of the result without defining
127: .Ar string
128: is equivalent to compiling
129: .Ar file1 ,
130: while defining
131: .Ar string
132: will yield
133: .Ar file2 .
1.2 deraadt 134: .It Fl e
1.5 jmc 135: Produces output in a form suitable as input for the editor utility,
1.1 deraadt 136: .Xr ed 1 ,
137: which can then be used to convert file1 into file2.
138: .Pp
139: Extra commands are added to the output when comparing directories with
140: .Fl e ,
141: so that the result is a
1.5 jmc 142: .Xr sh 1
1.1 deraadt 143: script for converting text files which are common to the two directories
144: from their state in
145: .Ar dir1
146: to their state in
147: .Ar dir2 .
1.2 deraadt 148: .It Fl f
1.5 jmc 149: Identical output to that of the
1.1 deraadt 150: .Fl e
1.5 jmc 151: flag, but in reverse order.
152: It cannot be digested by
1.1 deraadt 153: .Xr ed 1 .
1.2 deraadt 154: .It Fl n
1.5 jmc 155: Produces a script similar to that of
1.1 deraadt 156: .Fl e ,
157: but in the opposite order and with a count of changed lines on each
1.5 jmc 158: insert or delete command.
159: This is the form used by
160: .Xr rcsdiff 1 .
1.13 millert 161: .It Fl q
162: Just print a line when the files differ.
163: Does not output a list of changes.
1.31 jmc 164: .It Fl U Ar number
165: Like
166: .Fl u
167: but produces a diff with
168: .Ar number
169: lines of context.
1.6 millert 170: .It Fl u
171: Produces a
172: .Em unified
173: diff with 3 lines of context.
174: A unified diff is similar to the context diff produced by the
175: .Fl c
176: option.
177: However, unlike with
178: .Fl c ,
179: all lines to be changed (added and/or removed) are present in
180: a single section.
1.2 deraadt 181: .El
1.1 deraadt 182: .Pp
183: Comparison options:
1.2 deraadt 184: .Bl -tag -width Ds
1.11 millert 185: .It Fl a
1.26 otto 186: Treat all files as
1.28 jmc 187: .Tn ASCII
188: text.
189: Normally
190: .Nm
191: will simply print
192: .Dq Binary files ... differ
193: if files contain binary characters.
194: Use of this option forces
195: .Nm
196: to produce a diff.
1.2 deraadt 197: .It Fl b
1.5 jmc 198: Causes trailing blanks (spaces and tabs) to be ignored, and other
1.1 deraadt 199: strings of blanks to compare equal.
1.22 jmc 200: .It Fl d
201: Try very hard to produce a diff as small as possible.
202: This may consume a lot of processing power and memory when processing
203: large files with many changes.
1.26 otto 204: .It Fl I Ar pattern
205: Ignores changes, insertions, and deletions whose lines match the
206: extended regular expression
207: .Ar pattern .
208: Multiple
209: .Fl I
210: patterns may be specified.
211: All lines in the change must match some pattern for the change to be
212: ignored.
213: See
214: .Xr re_format 7
215: for more information on regular expression patterns.
1.16 millert 216: .It Fl i
217: Ignores the case of letters.
218: E.g.,
219: .Dq A
220: will compare equal to
221: .Dq a .
1.31 jmc 222: .It Fl L Ar label
223: Print
224: .Ar label
225: instead of the first (and second, if this option is specified twice)
226: file name and time in the context or unified diff header.
1.23 otto 227: .It Fl p
228: With unified and context diffs, show with each change
229: the first 40 characters of the last line before the context beginning
230: with a letter, an underscore or a dollar sign.
231: For C source code following standard layout conventions, this will
232: show the prototype of the function the change applies to.
1.31 jmc 233: .It Fl T
234: Print a tab rather than a space before the rest of the line for the
235: normal, context or unified output formats.
236: This makes the alignment of tabs in the line consistent.
1.2 deraadt 237: .It Fl t
1.5 jmc 238: Will expand tabs in output lines.
239: Normal or
1.1 deraadt 240: .Fl c
241: output adds character(s) to the front of each line which may screw up
242: the indentation of the original source lines and make the output listing
1.5 jmc 243: difficult to interpret.
244: This option will preserve the original source's indentation.
1.2 deraadt 245: .It Fl w
1.5 jmc 246: Is similar to
1.1 deraadt 247: .Fl b
1.5 jmc 248: but causes whitespace (blanks and tabs) to be totally ignored.
249: E.g.,
250: .Dq if (\ \&a == b \&)
251: will compare equal to
252: .Dq if(a==b) .
1.2 deraadt 253: .El
1.1 deraadt 254: .Pp
255: Directory comparison options:
1.2 deraadt 256: .Bl -tag -width Ds
1.11 millert 257: .It Fl N
258: If a file is found in only one directory, act as if it was found in the
259: other directory too but was of zero size.
1.12 millert 260: .It Fl P
261: If a file is found only in
262: .Ar dir2 ,
263: act as if it was found in
264: .Ar dir1
265: too but was of zero size.
1.2 deraadt 266: .It Fl r
1.5 jmc 267: Causes application of
268: .Nm
1.1 deraadt 269: recursively to common subdirectories encountered.
1.6 millert 270: .It Fl S Ar name
1.5 jmc 271: Re-starts a directory
272: .Nm
273: in the middle, beginning with file
1.1 deraadt 274: .Ar name .
1.31 jmc 275: .It Fl s
276: Causes
277: .Nm
278: to report files which are the same, which are otherwise not mentioned.
1.11 millert 279: .It Fl X Ar file
280: Exclude files and subdirectories from comparison whose basenames match
281: lines in
282: .Ar file .
283: Multiple
284: .Fl X
285: options may be specified.
286: .It Fl x Ar pattern
287: Exclude files and subdirectories from comparison whose basenames match
288: .Ar pattern .
289: Patterns are matched using shell-style globbing via
290: .Xr fnmatch 3 .
291: Multiple
292: .Fl x
293: options may be specified.
1.2 deraadt 294: .El
1.1 deraadt 295: .Pp
296: If both arguments are directories,
1.5 jmc 297: .Nm
1.1 deraadt 298: sorts the contents of the directories by name, and then runs the
299: regular file
1.5 jmc 300: .Nm
1.1 deraadt 301: algorithm, producing a change list,
302: on text files which are different.
303: Binary files which differ,
304: common subdirectories, and files which appear in only one directory
305: are described as such.
1.25 millert 306: In directory mode only regular files and directories are compared.
1.26 otto 307: If a non-regular file such as a device special file or
308: .Tn FIFO
309: is encountered, a diagnostic message is printed.
1.1 deraadt 310: .Pp
311: If only one of
312: .Ar file1
313: and
314: .Ar file2
315: is a directory,
1.5 jmc 316: .Nm
1.1 deraadt 317: is applied to the non-directory file and the file contained in
318: the directory file with a filename that is the same as the
319: last component of the non-directory file.
320: .Pp
1.2 deraadt 321: If either
1.1 deraadt 322: .Ar file1
323: or
324: .Ar file2
325: is
1.42 jmc 326: .Sq - ,
1.1 deraadt 327: the standard input is
328: used in its place.
329: .Ss Output Style
330: The default (without
331: .Fl e ,
332: .Fl c ,
333: or
334: .Fl n
1.5 jmc 335: .\" -C
1.1 deraadt 336: options)
337: output contains lines of these forms, where
338: .Va XX , YY , ZZ , QQ
339: are line numbers respective of file order.
340: .Pp
1.2 deraadt 341: .Bl -tag -width "XX,YYcZZ,QQ" -compact
342: .It Li XX Ns Ic a Ns Li YY
1.1 deraadt 343: At (the end of) line
344: .Va XX
345: of
346: .Ar file1 ,
347: append the contents
348: of line
349: .Va YY
350: of
351: .Ar file2
352: to make them equal.
1.2 deraadt 353: .It Li XX Ns Ic a Ns Li YY,ZZ
1.1 deraadt 354: Same as above, but append the range of lines,
355: .Va YY
356: through
357: .Va ZZ
358: of
359: .Ar file2
360: to line
361: .Va XX
362: of file1.
1.2 deraadt 363: .It Li XX Ns Ic d Ns Li YY
1.1 deraadt 364: At line
365: .Va XX
366: delete
1.5 jmc 367: the line.
368: The value
1.1 deraadt 369: .Va YY
1.5 jmc 370: tells to which line the change would bring
1.1 deraadt 371: .Ar file1
372: in line with
373: .Ar file1 .
1.2 deraadt 374: .It Li XX,YY Ns Ic d Ns Li ZZ
1.1 deraadt 375: Delete the range of lines
376: .Va XX
377: through
378: .Va YY
379: in
380: .Ar file1 .
1.2 deraadt 381: .It Li XX Ns Ic c Ns Li YY
1.1 deraadt 382: Change the line
383: .Va XX
384: in
385: .Ar file1
386: to the line
387: .Va YY
388: in
1.5 jmc 389: .Ar file2 .
1.2 deraadt 390: .It Li XX,YY Ns Ic c Ns Li ZZ
1.1 deraadt 391: Replace the range of specified lines with the line
392: .Va ZZ .
1.2 deraadt 393: .It Li XX,YY Ns Ic c Ns Li ZZ,QQ
1.1 deraadt 394: Replace the range
1.26 otto 395: .Va XX , Ns Va YY
1.1 deraadt 396: from
397: .Ar file1
398: with the range
1.26 otto 399: .Va ZZ , Ns Va QQ
1.1 deraadt 400: from
401: .Ar file2 .
1.2 deraadt 402: .El
1.1 deraadt 403: .Pp
404: These lines resemble
405: .Xr ed 1
406: subcommands to convert
407: .Ar file1
408: into
409: .Ar file2 .
410: The line numbers before the action letters pertain to
411: .Ar file1 ;
412: those after pertain to
413: .Ar file2 .
414: Thus, by exchanging
415: .Ic a
416: for
417: .Ic d
418: and reading the line in reverse order, one can also
419: determine how to convert
420: .Ar file2
421: into
422: .Ar file1 .
423: As in
424: .Xr ed 1 ,
425: identical
426: pairs (where num1 = num2) are abbreviated as a single
427: number.
428: .Sh ENVIRONMENT
1.2 deraadt 429: .Bl -tag -width TMPDIR
430: .It Ev TMPDIR
1.1 deraadt 431: If the environment variable
432: .Ev TMPDIR
433: exists,
1.5 jmc 434: .Nm
1.2 deraadt 435: will use the directory specified by
1.1 deraadt 436: .Ev TMPDIR
1.2 deraadt 437: as the temporary directory.
438: .El
1.1 deraadt 439: .Sh FILES
1.17 millert 440: .Bl -tag -width /tmp/diff.XXXXXXXX -compact
1.26 otto 441: .It Pa /tmp/diff. Ns Ar XXXXXXXX
1.17 millert 442: Temporary file used when comparing a device or the standard input.
443: Note that the temporary file is unlinked as soon as it is created
444: so it will not show up in a directory listing.
1.2 deraadt 445: .El
1.39 jmc 446: .Sh EXIT STATUS
1.1 deraadt 447: The
1.5 jmc 448: .Nm
1.1 deraadt 449: utility exits with one of the following values:
1.2 deraadt 450: .Pp
1.39 jmc 451: .Bl -tag -width Ds -offset indent -compact
1.30 jmc 452: .It 0
1.1 deraadt 453: No differences were found.
1.30 jmc 454: .It 1
1.1 deraadt 455: Differences were found.
1.43 jmc 456: .It >1
1.1 deraadt 457: An error occurred.
1.2 deraadt 458: .El
1.5 jmc 459: .Sh SEE ALSO
460: .Xr cmp 1 ,
461: .Xr comm 1 ,
462: .Xr diff3 1 ,
1.11 millert 463: .Xr ed 1 ,
1.38 schwarze 464: .Xr patch 1 ,
465: .Xr sdiff 1
1.40 jmc 466: .Rs
467: .%A James W. Hunt
468: .%A M. Douglas McIlroy
469: .%T "An Algorithm for Differential File Comparison"
470: .%J Computing Science Technical Report
471: .%Q Bell Laboratories 41
472: .%D June 1976
473: .Re
1.15 millert 474: .Sh STANDARDS
475: The
476: .Nm
1.32 jmc 477: utility is compliant with the
1.34 jmc 478: .St -p1003.1-2008
1.15 millert 479: specification.
1.32 jmc 480: .Pp
481: The flags
1.43 jmc 482: .Op Fl aDdIiLlNnPpqSsTtwXx ,
483: as well as the
484: .Ev TMPDIR
485: environment variable,
1.32 jmc 486: are extensions to that specification.
1.5 jmc 487: .Sh HISTORY
488: A
489: .Nm
490: command appeared in
491: .At v6 .