Name
diff — stdin stdout - file -- opt --help --version
Synopsis
diff [options
]file1 file2
The diff
command compares two files line by line,
or two directories. When comparing text files, 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. Macs r00l!
Then 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 > Macs r00l! 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.
Option | Output format |
| RCS version control format, as produced by the command ... |
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