diff.1 (2010 09)

diff(1) diff(1)

The following command ignores all blanks and tabs and ignores uppercase-lowercase differences.

diff -wi x1 x2

WARNINGS

Editing scripts produced by the -e or

-f option are naive about creating lines consisting of a single dot

(

.).

When comparing directories with the

-b,

-w,or -i options speciﬁed, diff ﬁrst compares the ﬁles in

the same manner as

cmp, then runs the

diff algorithm if they are not equal. This may cause a small

amount of spurious output if the ﬁles are identical except for insigniﬁcant blank strings or

uppercase/lowercase differences.

The default algorithm requires memory allocation of roughly six times the size of the ﬁle. If sufﬁcient

memory is not available for handling large ﬁles, the

-h option or bdiff can be used (see bdiff(1)).

With other options if sufﬁcient memory is not available, then either the

swap or maxdsiz values can be

increased.

When run on directories with the

-r option,

diff recursively descends sub-trees. When comparing

deep multi-level directories, more memory may be required than is currently available on the system.

The amount of memory required depends on the depth of recursion and the size of the ﬁles.

AUTHOR

diff was developed by AT&T, the University of California, Berkeley, and HP.

FILES

/usr/lbin/diffh used by

-h option