bdiff(1)

NAME

bdiff — diff for large files

SYNOPSIS

bdiff file1 file2 [n] [-s]

DESCRIPTION

bdiff compares two files and produces output identical to what would be produced by diff (see diff(1)), specifying changes that must be made to make the files identical. bdiff is designed for handling files that are too large for diff, but it can be used on files of any length.

bdiff processes files as follows:

Ignore lines common to the beginning of both files.
Split the remainder of each file into n-line segments, then execute diff on corresponding segments. The default value of n is 3500.

Command-Line Arguments

bdiff recognizes the following command-line arguments:

file1
file2: Names of two files to be compared by bdiff. If file1 or file2 (but not both) is -, standard input is used instead.
n: If a numeric value is present as the third argument, the files are divided into n-line segments before processing by diff. Default value for n is 3500. This option is useful when 3500-line segments are too large for processing by diff.
-s: Silent option suppresses diagnostic printing by bdiff, but does not suppress possible error messages from diff). If the n and -s arguments are both used, the n argument must precede the -s option on the command line or it will not be properly recognized.

EXTERNAL INFLUENCES

Environment Variables

LC_MESSAGES determines the language in which messages are displayed.

If LC_MESSAGES is not specified in the environment or is set to the empty string, the value of LANG is used as a default for each unspecified or empty variable. If LANG is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of LANG.

If any internationalization variable contains an invalid setting, bdiff behaves as if all internationalization variables are set to "C". See environ(5).

International Code Set Support

Single- and multi-byte character code sets are supported.

DIAGNOSTICS

both files standard input (bd2): Standard input was specified for both files. Only one file can be specified as standard input.
non-numeric limit (bd4): A non-numeric value was specified for the n (third) argument.

EXAMPLES

Find differences between two large files: file1 and file2, and place the result in a new file named diffs_1.2.

bdiff file1 file2 >diffs_1.2 

Do the same, but limit file length to 1400 lines; suppress error messages:

bdiff file1 file2 1400 -s >diffs_1.2 

WARNINGS

bdiff produces output identical to output from diff, and makes the necessary line-number corrections so that the output looks like it was processed by diff. However, depending on where the files are split, bdiff may or may not find a fully minimized set of file differences.

FILES

/tmp/bd??????