# indent > Change the appearance of a C/C++ program by inserting or deleting whitespace. > More information: . - Format C/C++ source according to the Linux style guide, automatically back up the original files, and replace with the indented versions: `indent --linux-style {{path/to/source.c}} {{path/to/another_source.c}}` - Format C/C++ source according to the GNU style, saving the indented version to a different file: `indent --gnu-style {{path/to/source.c}} -o {{path/to/indented_source.c}}` - Format C/C++ source according to the style of Kernighan & Ritchie (K&R), no tabs, 3 spaces per indent, and wrap lines at 120 characters: `indent --k-and-r-style --indent-level3 --no-tabs --line-length120 {{path/to/source.c}} -o {{path/to/indented_source.c}}`