散装知识点

Patching with command diff and patch

diff -ruN OldFile NewFile > x.patch

• -r : recursively compare any subdirectories found
• -u/-U NUM : output NUM (default 3) lines of unified context
• -N : treat absent files as empty

patch -pN -RE oldFile x.patch

• -pN : Strip NUM leading components from file names eg : a/b/c/d/file ,patch -p0 ,cd a ,patch -p1 ,cd b ,patch -p2 ,...

• -R : Assume patches were created with old and new files swapped

• -E : Remove output files that are empty after patching

Tips : Order is important for OldFile and NewFile in command 'diff', and the same with the option -R for command 'patch'

Note : Patching means operations based on original files