berk_diff(1) DG/UX R4.11MU05 berk_diff(1)
NAME
berkdiff - Berkeley differential file and directory comparator
SYNOPSIS
berkdiff [ -l ] [ -r ] [ -s ] [ -cefhn ] [ -biwt ] [ -Sname ] dir1
dir2
berkdiff [ -cefhn ] [ -biwt ] file1 file2
berkdiff [ -Dstring ] [ -biw ] file1 file2
DESCRIPTION
If both arguments are directories, berkdiff sorts the contents of
the directories by name, and then runs the regular file berkdiff
algorithm (described below) on text files which are different.
Binary files which differ, common subdirectories, and files which
appear in only one directory are listed. Options when comparing
directories are:
-l long output format; each text file berkdiff is piped through
pr(1) to paginate it, other differences are remembered and
summarized after all text file differences are reported.
-r causes application of berkdiff recursively to common
subdirectories encountered.
-s causes berkdiff to report files which are the same, which are
otherwise not mentioned.
-Sname starts a directory berkdiff in the middle beginning with file
name.
When run on regular files, and when comparing text files which differ
during directory comparison, berkdiff tells what lines must be
changed in the files to bring them into agreement. Except in rare
circumstances, berkdiff finds a smallest sufficient set of file
differences. If neither file1 nor file2 is a directory, then either
may be given as `-', in which case the standard input is used. If
file1 is a directory, then a file in that directory whose filename is
the same as the filename of file2 is used (and vice versa).
There are several options for output format; the default output
format contains lines of these forms:
n1 a n3,n4
n1,n2 d n3
n1,n2 c n3,n4
These lines resemble ed commands to convert file1 into file2. The
numbers after the letters pertain to file2. In fact, by exchanging
`a' for `d' and reading backward one may ascertain equally how to
convert file2 into file1. As in ed, identical pairs where n1 = n2 or
n3 = n4 are abbreviated as a single number.
Following each of these lines come all the lines that are affected in
the first file flagged by `<', then all the lines that are affected
in the second file flagged by `>'.
Except for -b, -w, -i or -t which may be given with any of the
others, the following options are mutually exclusive:
-e produces a script of a, c and d commands for the editor ed,
which will recreate file2 from file1. In connection with
-e, the following shell program may help maintain multiple
versions of a file. Only an ancestral file ($1) and a chain
of version-to-version ed scripts ($2,$3,...) made by
berkdiff need be on hand. A `latest version' appears on
the standard output.
(shift; cat $*; echo '1,$p') | ed - $1
Extra commands are added to the output when comparing
directories with -e, so that the result is a sh(1) script
for converting text files which are common to the two
directories from their state in dir1 to their state in dir2.
-f produces a script similar to that of -e, not useful with ed,
and in the opposite order.
-n produces a script similar to that of -e, but in the opposite
order and with a count of changed lines on each insert or
delete command. This is the form used by rcsdiff(1).
-c produces a berk_diff with lines of context. The default is
to present 3 lines of context and may be changed, e.g to 10,
by -c10. With -c the output format is modified slightly:
the output beginning with identification of the files
involved and their creation dates and then each change is
separated by a line with a dozen *'s. The lines removed
from file1 are marked with `- '; those added to file2 are
marked `+ '. Lines which are changed from one file to the
other are marked in both files with with `! '.
Changes which lie within context lines of each other are
grouped together on output. (This is a change from the
previous ``berk_diff -c'' but the resulting output is
usually much easier to interpret.)
-h does a fast, half-hearted job. It works only when changed
stretches are short and well separated, but does work on
files of unlimited length.
-Dstring causes berkdiff to create a merged version of file1 and
file2 on the standard output, with C preprocessor controls
included so that a compilation of the result without
defining string is equivalent to compiling file1, while
defining string will yield file2.
-b causes trailing blanks (spaces and tabs) to be ignored, and
other strings of blanks to compare equal.
-w is similar to -b but causes whitespace (blanks and tabs) to
be totally ignored. E.g., ``if ( a == b )'' will compare
equal to ``if(a==b)''.
-i ignores the case of letters. E.g., ``A'' will compare equal
to ``a''.
-t will expand tabs in output lines. Normal or -c output adds
character(s) to the front of each line which may misalign
the indentation of the original source lines and make the
output listing difficult to interpret. This option will
preserve the original source's indentation.
FILES
/tmp/d?????
/usr/lib/diffh for -h
/bin/diff for directory diffs
/bin/pr
DIAGNOSTICS
Exit status is 0 for no differences, 1 for some, 2 for trouble.
SEE ALSO
berkdiff3(1), cc(1), cmp(1), comm(1), diff(1), diff3(1), ed(1).
NOTES
Editing scripts produced under the -e or -f option are naive about
creating lines consisting of a single `.'.
When comparing directories with the -b, -w or -i options specified,
berkdiff first compares the files ala cmp, and then decides to run
the berkdiff algorithm if they are not equal. This may cause a
small amount of spurious output if the files then turn out to be
identical because the only differences are insignificant blank string
or case differences.
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