cd /var/tmp cp -a old_wrk new_wrk cd new_wrk # create new files and modify existing ones # …

# now record all the changes we introduced cd ${HOME} diff -ruN /var/tmp/old_wrk /var/tmp/new_wrk > update.patch

cd /var/tmp patch -b -uN -d old_wrk -p 4 < ${HOME}/update.patch

diff –help

Usage: diff [OPTION]… FILES Compare files line by line. -i –ignore-case Ignore case differences in file contents. –ignore-file-name-case Ignore case when comparing file names. –no-ignore-file-name-case Consider case when comparing file names. -E –ignore-tab-expansion Ignore changes due to tab expansion. -b –ignore-space-change Ignore changes in the amount of white space. -w –ignore-all-space Ignore all white space. -B –ignore-blank-lines Ignore changes whose lines are all blank. -I RE –ignore-matching-lines=RE Ignore changes whose lines all match RE. –strip-trailing-cr Strip trailing carriage return on input. -a –text Treat all files as text. -c -C NUM –context[=NUM] Output NUM (default 3) lines of copied context. -u -U NUM –unified[=NUM] Output NUM (default 3) lines of unified context. –label LABEL Use LABEL instead of file name. -p –show-c-function Show which C function each change is in. -F RE –show-function-line=RE Show the most recent line matching RE. -q –brief Output only whether files differ. -e –ed Output an ed script. –normal Output a normal diff. -n –rcs Output an RCS format diff. -y –side-by-side Output in two columns. -W NUM –width=NUM Output at most NUM (default 130) print columns. –left-column Output only the left column of common lines. –suppress-common-lines Do not output common lines. -D NAME –ifdef=NAME Output merged file to show `#ifdef NAME’ diffs. –GTYPE-group-format=GFMT Similar, but format GTYPE input groups with GFMT. –line-format=LFMT Similar, but format all input lines with LFMT. –LTYPE-line-format=LFMT Similar, but format LTYPE input lines with LFMT. LTYPE is `old’, `new’, or `unchanged’. GTYPE is LTYPE or `changed’. GFMT may contain: %< lines from FILE1 %> lines from FILE2 %= lines common to FILE1 and FILE2 %[-][WIDTH][.[PREC]]{doxX}LETTER printf-style spec for LETTER LETTERs are as follows for new group, lower case for old group: F first line number L last line number N number of lines = L-F+1 E F-1 M L+1 LFMT may contain: %L contents of line %l contents of line, excluding any trailing newline %[-][WIDTH][.[PREC]]{doxX}n printf-style spec for input line number Either GFMT or LFMT may contain: %% % %c’C’ the single character C %c’\OOO’ the character with octal code OOO -l –paginate Pass the output through `pr’ to paginate it. -t –expand-tabs Expand tabs to spaces in output. -T –initial-tab Make tabs line up by prepending a tab. -r –recursive Recursively compare any subdirectories found. -N –new-file Treat absent files as empty. –unidirectional-new-file Treat absent first files as empty. -s –report-identical-files Report when two files are the same. -x PAT –exclude=PAT Exclude files that match PAT. -X FILE –exclude-from=FILE Exclude files that match any pattern in FILE. -S FILE –starting-file=FILE Start with FILE when comparing directories. –from-file=FILE1 Compare FILE1 to all operands. FILE1 can be a directory. –to-file=FILE2 Compare all operands to FILE2. FILE2 can be a directory. –horizon-lines=NUM Keep NUM lines of the common prefix and suffix. -d –minimal Try hard to find a smaller set of changes. –speed-large-files Assume large files and many scattered small changes. -v –version Output version info. –help Output this help. FILES are `FILE1 FILE2′ or `DIR1 DIR2′ or `DIR FILE…’ or `FILE… DIR’. If –from-file or –to-file is given, there are no restrictions on FILES. If a FILE is `-‘, read standard input. Report bugs to .

patch –help

Usage: patch [OPTION]… [ORIGFILE [PATCHFILE]] Input options: -p NUM –strip=NUM Strip NUM leading components from file names. -F LINES –fuzz LINES Set the fuzz factor to LINES for inexact matching. -l –ignore-whitespace Ignore white space changes between patch and input. -c –context Interpret the patch as a context difference. -e –ed Interpret the patch as an ed script. -n –normal Interpret the patch as a normal difference. -u –unified Interpret the patch as a unified difference. -N –forward Ignore patches that appear to be reversed or already applied. -R –reverse Assume patches were created with old and new files swapped. -i PATCHFILE –input=PATCHFILE Read patch from PATCHFILE instead of stdin. Output options: -o FILE –output=FILE Output patched files to FILE. -r FILE –reject-file=FILE Output rejects to FILE. -D NAME –ifdef=NAME Make merged if-then-else output using NAME. -m –merge Merge using conflict markers instead of creating reject files. -E –remove-empty-files Remove output files that are empty after patching. -Z –set-utc Set times of patched files, assuming diff uses UTC (GMT). -T –set-time Likewise, assuming local time. –quoting-style=WORD output file names using quoting style WORD. Valid WORDs are: literal, shell, shell-always, c, escape. Default is taken from QUOTING_STYLE env variable, or ‘shell’ if unset. Backup and version control options: -b –backup Back up the original contents of each file. –backup-if-mismatch Back up if the patch does not match exactly. –no-backup-if-mismatch Back up mismatches only if otherwise requested. -V STYLE –version-control=STYLE Use STYLE version control. STYLE is either ‘simple’, ‘numbered’, or ‘existing’. -B PREFIX –prefix=PREFIX Prepend PREFIX to backup file names. -Y PREFIX –basename-prefix=PREFIX Prepend PREFIX to backup file basenames. -z SUFFIX –suffix=SUFFIX Append SUFFIX to backup file names. -g NUM –get=NUM Get files from RCS etc. if positive; ask if negative. Miscellaneous options: -t –batch Ask no questions; skip bad-Prereq patches; assume reversed. -f –force Like -t, but ignore bad-Prereq patches, and assume unreversed. -s –quiet –silent Work silently unless an error occurs. –verbose Output extra information about the work being done. –dry-run Do not actually change any files; just print what would happen. –posix Conform to the POSIX standard. -d DIR –directory=DIR Change the working directory to DIR first. –reject-format=FORMAT Create ‘context’ or ‘unified’ rejects. –binary Read and write data in binary mode. -v –version Output version info. –help Output this help. Report bugs to .