I'm trying to compare files ignoring carriage returns - which diff -b on any other unix performs admirably. But on this AIX 5.3 box:
tst1:tst2$ od -c testfile
0000000 t h i s \r \n f i l e \r \n h a s \r
0000020 \n c a r r i a g e \r \n r e t u r
0000040 n s \r \n
0000044
tst1:tst2$ od -c testfile_nocr
0000000 t h i s \n f i l e \n h a s \n c a
0000020 r r i a g e \n r e t u r n s \n
0000037
tst1:tst2$ diff -b testfile testfile_nocr
1,5c1,5
< this
< file
< has
< carriage
< returns
---
> this
> file
> has
> carriage
> returns
tst1:tst2$
Why so?
AIX 5.3 diff does not appear to consider \r as white space. See the following transcript:
/home/pax: od -c file1
0000000 h e l l o \n t h e r e \n
0000014
/home/pax: od -c file2
0000000 h e l l o \r \n t h e r e \r \n
0000016
/home/pax: od -c file3
0000000 h e l l o \n t h e r e \n
0000016
/home/pax: od -c file4
0000000 h e l l o \t \n t h e r e \t \n
0000016
/home/pax: diff -b file1 file2
1,2c1,2
< hello
< there
---
> hello
> there
/home/pax: diff -b file1 file3
<<No output>>
/home/pax: diff -b file1 file4
<<No output>>
The manpage for diff is a little obtuse on the matter, stating that -b will "cause any amount of white space at the end of the line to be treated as a single newline character ..." but does not actually define what it considers to be white space.
Based on the above transcript, I would gather that spaces and tabs are okay but carriage returns are not.
One way to get around this will be to remove the carriage returns yourself with a script like:
#!/usr/bin/ksh
# crdiff: diffs two files after changing \r\n to \n in both.
if [[ $# -ne 2 ]] ; then
echo 'Usage: crdiff <file> <file2>'
return 1
fi
perl -pne 's/\r$//' $1 >/tmp/xyzzy_$$_$1
perl -pne 's/\r$//' $2 >/tmp/xyzzy_$$_$2
diff -b /tmp/xyzzy_$$_$1 /tmp/xyzzy_$$_$2
rc=$?
rm -f /tmp/xyzzy_$$_$1 /tmp/xyzzy_$$_$2
return $rc
Alternatively, you could compile the GNU diff utility on your box and insert it into the path before /usr/bin - it appears to have no trouble with \r as white space. In fact, we do exactly that on our AIX4 boxes since diff there doesn't even pretend to support the -b option.