diff — stdin stdout - file -- opt --help --version
diff command compares
two files line-by-line, or two directories. When comparing text
diff can produce detailed
reports of their differences. For binary files,
diff merely reports whether they differ or
not. For all files, if there are no differences,
diff produces no output.
The traditional output format looks like this:
Indication of line numbers and the type of change < Corresponding section of file1, if any --- > Corresponding section of file2, if any
For example, if we start with a file fileA:
Hello, this is a wonderful file. The quick brown fox jumped over the lazy dogs. Goodbye for now.
Suppose we delete the first line, change “brown” to “blue” on the second line, and add a final line, creating a file fileB:
The quick blue fox jumped over the lazy dogs. Goodbye for now. Linux r00lz!
diff fileA fileB
produces this output:
1,2c1 fileA lines 1-2 became fileB line 1 < Hello, this is a wonderful file. Lines 1-2 of fileA < The quick brown fox jumped over --- diff separator > The quick blue fox jumped over Line 1 of fileB 4a4 Line 4 was added in fileB > Linux r00lz! The added line
The leading symbols < and > are arrows indicating fileA and fileB, respectively. This output format is the default: many others are available, some of which can be fed directly to other tools. Try them out to see what they look like.
RCS version control format, as produced ...