I diff-ed 2 files and got
1c1 < 1 --- > 1
Both files contained just "1". How is this different?
2nd line: line with
3rd line is a divider.
4th line: line with
(If you ever see
And your problem might be whitespaces or other non-human readable characters: those trigger a difference too.
There are some options to manipulate output.
rinzwind@discworld:~$ more 1 test test2 test3 rinzwind@discworld:~$ more 2 test test2 test3
rinzwind@discworld:~$ diff -c 1 2 *** 1 2011-08-13 17:05:40.433966684 +0200 --- 2 2011-08-13 17:11:24.369966629 +0200 *************** *** 1,3 **** test ! test2 test3 --- 1,3 ---- test ! test2 test3
A "!" represents a change between lines that correspond in the two files. A "+" represents the addition of a line, while a blank space represents an unchanged line. At the beginning of the patch is the file information, including the full path and a time stamp. At the beginning of each hunk are the line numbers that apply for the corresponding change in the files. A number range appearing between sets of three asterisks applies to the original file, while sets of three dashes apply to the new file. The hunk ranges specify the starting and ending line numbers in the respective file.
Expanding on Lekensteyn's comment about unified format:
rinzwind@discworld:~$ diff -u 1 2 --- 1 2011-08-13 17:05:40.433966684 +0200 +++ 2 2011-08-13 17:11:24.369966629 +0200 @@ -1,3 +1,3 @@ test -test2 +test2 test3
The format starts with the same two-line header as the context format, except that the original file is preceded by "---" and the new file is preceded by "+++". Following this are one or more change hunks that contain the line differences in the file. The unchanged, contextual lines are preceded by a space character, addition lines are preceded by a plus sign, and deletion lines are preceded by a minus sign.
Some useful options:
I find od (octal dump) to be handy when comparing files w/ non-printable characters (particularly files which diff decides are "binary" and thus tells you only that they do differ).
In the example below, I create a pair of files that could be like the original ones, then do a diff with the original output; next I do diff on a couple of different "od" outputs.
$ echo 1 > 1
$ od -c 1 > 1.od
$ od -Ax -c -t x1 1 > 1.od
Not sure if this helps with hard to find whitespace characters, but it's handy for diffing: http://www.gnu.org/software/wdiff/
i had the same problem and i found a solution that might help, use the command :
one of them might be in a dos/windows format and the other one UNIX format
after i did this the diff was all good!