diff 로 patch 파일 만들기

$ diff -urN ori_dir modified_dir > patch.diff

       -u     Use the unified output format.
       -r     When comparing directories, recursively compare any subdirectories found.
       -N
       --new-file
              In directory comparison, if a file is found in only one directory, treat it as present but  empty  in  the
              other directory.

일반적으로 GNU 프로젝트의 패치로 사용하는 옵션이라고 한다.
-u는 unified 포맷 출력
-r은 디렉토리 비교
-N은 새 파일이 있을시 없는쪽은 비어있는 파일로 간주하고 비교함
 간단하게 전부 내용이 추가된걸로 표시된다. 이러한 옵션 없이 diff하면 아래와 같이 빈 파일이 출력된다.

Only in linux-2.6.17.14_stm22_0039_STFAE: .config2

하지만 -N 옵션을 넣으주면 아래와 같이 출력이 된다.

diff -urN linux-2.6.17.14_stm22_0039_STFAE_ORI/.config2 linux-2.6.17.14_stm22_0039_STFAE/.config2 --- linux-2.6.17.14_stm22_0039_STFAE_ORI/.config2       1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.17.14_stm22_0039_STFAE/.config2   2008-09-12 12:32:23.000000000 +0900 @@ -0,0 +1,1312 @@ +# +# source code ...

$ man diff
DIFF(1)                            GNU Tools                           DIFF(1)

NAME
       diff - find differences between two files

SYNOPSIS
       diff [options] from-file to-file

DESCRIPTION
       In the simplest case, diff compares the contents of the two files from-file and to-file.  A file name of - stands
       for text read from the standard input.  As a special case, diff - - compares a copy of standard input to  itself.

       If  from-file  is  a directory and to-file is not, diff compares the file in from-file whose file name is that of
       to-file, and vice versa.  The non-directory file must not be -.

       If both from-file and to-file are directories, diff compares corresponding files in both directories,  in  alpha-
       betical  order;  this  comparison is not recursive unless the -r or --recursive option is given.  diff never com-
       pares the actual contents of a directory as if it were a file.  The file that is fully specified may not be stan-
       dard input, because standard input is nameless and the notion of ‘‘file with the same name’’ does not apply.

       diff options begin with -, so normally from-file and to-file may not begin with -.  However, -- as an argument by
       itself treats the remaining arguments as file names even if they begin with -.

   Options
       Below is a summary of all of the options that GNU diff accepts.  Most options have two equivalent names,  one  of
       which  is  a  single letter preceded by -, and the other of which is a long name preceded by --.  Multiple single
       letter options (unless they take an argument) can be combined into a single command line word: -ac is  equivalent
       to -a -c.  Long named options can be abbreviated to any unique prefix of their name.  Brackets ([ and ]) indicate
       that an option takes an optional argument.

       -lines Show lines (an integer) lines of context.  This option does not specify an output format by itself; it has
              no effect unless it is combined with -c or -u.  This option is obsolete.  For proper operation, patch typ-
              ically needs at least two lines of context.

       -a     Treat all files as text and compare them line-by-line, even if they do not seem to be text.

       -b     Ignore changes in amount of white space.

       -B     Ignore changes that just insert or delete blank lines.

       --brief
              Report only whether the files differ, not the details of the differences.

       -c     Use the context output format.

       -C lines
       --context[=lines]
              Use the context output format, showing lines (an integer) lines of context,  or  three  if  lines  is  not
              given.  For proper operation, patch typically needs at least two lines of context.

       --changed-group-format=format
              Use format to output a line group containing differing lines from both files in if-then-else format.

       -d     Change  the  algorithm  to  perhaps find a smaller set of changes.  This makes diff slower (sometimes much
              slower).

       -D name
              Make merged if-then-else format output, conditional on the preprocessor macro name.

       -e
       --ed   Make output that is a valid ed script.

       --exclude=pattern
              When comparing directories, ignore files and subdirectories whose basenames match pattern.

       --exclude-from=file
              When comparing directories, ignore files and subdirectories whose basenames match any pattern contained in
              file.

       --expand-tabs
              Expand tabs to spaces in the output, to preserve the alignment of tabs in the input files.

       -f     Make output that looks vaguely like an ed script but has changes in the order they appear in the file.

       -F regexp
              In  context  and  unified  format, for each hunk of differences, show some of the last preceding line that
              matches regexp.

       --forward-ed
              Make output that looks vaguely like an ed script but has changes in the order they appear in the file.

       -h     This option currently has no effect; it is present for Unix compatibility.

       -H     Use heuristics to speed handling of large files that have numerous scattered small changes.

       --horizon-lines=lines
              Do not discard the last lines lines of the common prefix and the first lines lines of the common suffix.

       -i     Ignore changes in case; consider upper- and lower-case letters equivalent.

       -I regexp
              Ignore changes that just insert or delete lines that match regexp.

       --ifdef=name
              Make merged if-then-else format output, conditional on the preprocessor macro name.

       --ignore-all-space
              Ignore white space when comparing lines.

       --ignore-blank-lines
              Ignore changes that just insert or delete blank lines.

       --ignore-case
              Ignore changes in case; consider upper- and lower-case to be the same.

       --ignore-matching-lines=regexp
              Ignore changes that just insert or delete lines that match regexp.

       --ignore-space-change
              Ignore changes in amount of white space.

       --initial-tab
              Output a tab rather than a space before the text of a line in normal or context format.  This  causes  the
              alignment of tabs in the line to look normal.

       -l     Pass the output through pr to paginate it.

       -L label
       --label=label
              Use label instead of the file name in the context format and unified format headers.

       --left-column
              Print only the left column of two common lines in side by side format.

       --line-format=format
              Use format to output all input lines in in-then-else format.

       --minimal
              Change  the  algorithm  to  perhaps find a smaller set of changes.  This makes diff slower (sometimes much
              slower).

       -n     Output RCS-format diffs; like -f except that each command specifies the number of lines affected.

       -N
       --new-file
              In directory comparison, if a file is found in only one directory, treat it as present but  empty  in  the
              other directory.

       --new-group-format=format
              Use format to output a group of lines taken from just the second file in if-then-else format.

       --new-line-format=format
              Use format to output a line taken from just the second file in if-then-else format.

       --old-group-format=format
              Use format to output a group of lines taken from just the first file in if-then-else format.

       --old-line-format=format
              Use format to output a line taken from just the first file in if-then-else format.

       -p     Show which C function each change is in.

       -P     When comparing directories, if a file appears only in the second directory of the two, treat it as present
              but empty in the other.

       --paginate
              Pass the output through pr to paginate it.

       -q     Report only whether the files differ, not the details of the differences.

       -r     When comparing directories, recursively compare any subdirectories found.

       --rcs  Output RCS-format diffs; like -f except that each command specifies the number of lines affected.

       --recursive
              When comparing directories, recursively compare any subdirectories found.

       --report-identical-files
       -s     Report when two files are the same.

       -S file
              When comparing directories, start with the file file.  This is used for resuming an aborted comparison.

       --from-file=file
              Compare file to all operands.  file can be a directory.

       --to-file=file
              Compare all operands to file. file can be a directory.

       --sdiff-merge-assist
              Print extra information to help sdiff.  sdiff uses this option when it runs  diff.   This  option  is  not
              intended for users to use directly.

       --show-c-function
              Show which C function each change is in.

       --show-function-line=regexp
              In  context  and  unified  format, for each hunk of differences, show some of the last preceding line that
              matches regexp.

       --side-by-side
              Use the side by side output format.

       --speed-large-files
              Use heuristics to speed handling of large files that have numerous scattered small changes.

       --starting-file=file
              When comparing directories, start with the file file.  This is used for resuming an aborted comparison.

       --suppress-common-lines
              Do not print common lines in side by side format.

       -t     Expand tabs to spaces in the output, to preserve the alignment of tabs in the input files.

       -T     Output a tab rather than a space before the text of a line in normal or context format.  This  causes  the
              alignment of tabs in the line to look normal.

       --text Treat all files as text and compare them line-by-line, even if they do not appear to be text.

       -u     Use the unified output format.

       --unchanged-group-format=format
              Use format to output a group of common lines taken from both files in if-then-else format.

       --unchanged-line-format=format

       --suppress-common-lines
              Do not print common lines in side by side format.

       -t     Expand tabs to spaces in the output, to preserve the alignment of tabs in the input files.

       -T     Output a tab rather than a space before the text of a line in normal or context format.  This  causes  the
              alignment of tabs in the line to look normal.

       --text Treat all files as text and compare them line-by-line, even if they do not appear to be text.

       -u     Use the unified output format.

       --unchanged-group-format=format
              Use format to output a group of common lines taken from both files in if-then-else format.

       --unchanged-line-format=format
              Use format to output a line common to both files in if-then-else format.

       --unidirectional-new-file
              When comparing directories, if a file appears only in the second directory of the two, treat it as present
              but empty in the other.

       -U lines
       --unified[=lines]
              Use the unified output format, showing lines (an integer) lines of context,  or  three  if  lines  is  not
              given.  For proper operation, patch typically needs at least two lines of context.

       -v
       --version
              Output the version number of diff.

       -w     Ignore white space when comparing lines.

       -W columns
       --width=columns
              Use an output width of columns in side by side format.

       -x pattern
              When comparing directories, ignore files and subdirectories whose basenames match pattern.

       -X file
              When comparing directories, ignore files and subdirectories whose basenames match any pattern contained in
              file.

       -y     Use the side by side output format.

SEE ALSO
       cmp(1), comm(1), diff3(1), ed(1), patch(1), pr(1), sdiff(1).

DIAGNOSTICS
       An exit status of 0 means no differences were found, 1 means some differences were found, and 2 means trouble.

GNU Tools                          22sep1993                           DIFF(1)

[링크 : http://wiki.kldp.org/wiki.php/DiffAndPatch]