how to use diff to only print lines

fancylad · 07-08-2008, 02:09 PM

Hi,

How do I use diff to only print out the actual differences between two text files, and not all those numbers? I have been searching through the man page but don't see a way to do it. Perhaps I have missed something.

Thanks

trickykid · 07-08-2008, 02:17 PM

What version are you using? I'm on Fedora Core 8 and by default it seems it only prints off the lines that are different.

Examples:

file1:

Code:

this is a line
that is only text.

blah

file2

Code:

this is a line
that is only text.

blah 2

Sample output of diff:

Code:

[trickykid@your-momma ~]$ diff file1 file2
4c4
< blah
---
> blah 2

fancylad · 07-08-2008, 02:30 PM

sorry. i mean only the lines and not those numbers that precede the line. so for your example i would like to see:

Quote:

blah
blah2

and not

Quote:

4c4
< blah
---
> blah 2

trickykid · 07-08-2008, 02:36 PM

Well, I'd say you want to keep the < and > cause they indicate which file the line resides in. It would get sort of messy looking at more lines with differences.

But to remove the other stuff, you could easily grep them out.

Code:

diff file1 file2 | grep -v "^---" | grep -v "^[0-9c0-9]"

Code:

[trickykid@your-momma ~]$ diff file1 file2 | grep -v "^---" | grep -v "^[0-9c0-9]"
< blah
> blah 2

fancylad · 07-08-2008, 02:43 PM

Thanks. I already used that grep method but I'm not crazy about using it. I thought that diff would be capable of doing this on its own.

trickykid · 07-08-2008, 02:51 PM

You could always do the side by side type format which is rather nice and I tend to use it more often, easier to read on smaller files at least:

Code:

[trickykid@your-momma ~]$ diff --suppress-common-lines -y file1 file2
blah                                                          | blah 2

rjlee · 07-08-2008, 03:55 PM

Try this:

Code:

diff --line-format=%L file1 file2

trickykid · 07-08-2008, 04:34 PM

Quote:

Originally Posted by rjlee

Try this:

Code:

diff --line-format=%L file1 file2

Yeah, forgot about the line format, hadn't been reading the man page but that didn't seem to work for me.

Code:

[trickykid@your-momma ~]$ diff --line-format=%L file1 file2
this is a line
that is only text.

blah
blah 2