z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

diff
Description
Options
The diff command attempts to determine the minimal set of changes needed to
convert a file whose name is specified by the path1 argument into the file specified
by the path2 argument.
Input files must be text files. If either (but only one) filename is –, diff uses a copy
of the standard input (stdin) for that file. If exactly one of path1 or path2 is a
directory, diff uses a file in that directory with the same name as the other filename.
If both are directories, diff compares files with the same filenames under the two
directories; however, it does not compare files in subdirectories unless you specify
the –r option. When comparing two directories, diff does not compare character
special files, or FIFO special files with any other files.
By default, output consists of descriptions of the changes in a style like that of the
ed text editor. A line indicating the type of change is given. The three types are a
(append), d (delete), and c (change). The output is symmetric: A delete in path1 is
the counterpart of an append in path2. diff prefixes each operation with a line
number (or range) in path1 and suffixes each with a line number (or range) in
path2. After the line giving the type of change, diff displays the deleted or added
lines, prefixing lines from path1 with < and lines from path2 with >.
Options that control the output or style of file comparison are:
–b Ignores trailing blanks and tabs and considers adjacent groups of blanks
and tabs elsewhere in input lines to be equivalent.
For example, if one file contained a string of three spaces and a tab at a
given location while the other file contained a string of two spaces at the
same location, diff would not report this as a difference.
–C n Shows n lines of context before and after each change. diff marks lines
removed from path1 with –, lines added to path2 with +, and lines changed
in both files with !.
–c[n] Is equivalent to –Cn, but n is optional. The default value for n is 3. diff
marks lines removed from path1 with –, lines added to path2 with +, and
lines changed in both files with !.
–Difname
Displays output that is the appropriate input to the C preprocessor to
generate the contents of path2 when ifname is defined, and the contents of
path1 when ifname is not defined.
–e Writes out a script of commands for the ed text editor, which converts path1
to path2. diff sends the output to the standard output (stdout).
–f Writes a script to stdout (but it will be in a form not suitable for use with the
ed editor) showing the modifications necessary to convert path1 to path2 in
the reverse order of that produced by the –e option. The commands
produced will be reversed from that produced by –e, and the line number
ranges will be separated by spaces, rather than commas. This option
conflicts with the –m option.
–H Uses the half-hearted (–h) algorithm only if the normal algorithm runs out of
system resources.
–h Uses a fast, half-hearted algorithm instead of the normal diff algorithm. This
236 z/OS V1R9.0 UNIX System Services Command Reference