diff commands for shell

diff_commands.sh

# The difference between two folders
diff folder_1 folder_2

# The difference between two files
diff file_1.txt file_2.txt

# The difference between two folders recursive
diff -r folder_1 folder_2

# Create a patch file from a diff
diff file_1.txt file_2.txt > example.patch

# Create a patch file from a diff in unified format ( Denotes what file to be patched in a header)
diff -u file_1.txt file_2.txt > example.patch

# Patch a file
patch file_1.txt < example.patch

# Patch a file form a patch in unified format
patch < example.patch

# Remove a patch
patch file_1.txt -R < example.patch

# Flags

# Recursive, compares every corresponding pair of files in the directory trees, as many levels deep as they go
diff --recursive folder_1 folder_2
# or
diff -r folder_1 folder_2

# Report identical files
diff --report-identical-files folder_1 folder_2
# or
diff -s folder_1 folder_2 

# Exclude. This option ignores any files or subdirectories whose base names match the shell pattern
diff --exclude=pattern  folder_1 folder_2
# or
diff -x pattern folder_1 folder_2

# http://www.gnu.org/software/diffutils/manual/html_node/index.html