1# Checkout vs Update 2 3Fossil has two commands that look like they do the same thing on initial 4examination, [`fossil update`][up] and [`fossil checkout`][co], but 5there are several key differences: 6 71. `fossil checkout` aborts if there are changed files in the local 8 directory unless you give the `--force` option, whereas 9 `fossil update` merges upstream changes with your local changes. 10 Since Fossil tends to follow the CVS command design, and CVS 11 popularized the [merge on update][cvsmu] workflow, we expect that 12 Fossil’s update behavior is more likely to be what you want. 13 142. Update triggers an autosync attempt; checkout does not. 15 163. Several features in `fossil update` do not exist in 17 `fossil checkout`, so developing a habit to type `fossil up` 18 means you’re more likely to have the features you want at hand. 19 204. Inversely, the `fossil checkout --keep` feature doesn’t exist in 21 `fossil update`, but it’s a rarely-needed operation, so it doesn’t 22 provide a good reason to develop a habit of using `fossil checkout` 23 instead. 24 25In summary, these are two separate commands; neither is an alias for the 26other. They overlap enough that they can be used interchangeably for 27some use cases, but `update` is more powerful and more broadly useful. 28 29[co]: /help?cmd=checkout 30[cvsmu]: http://web.mit.edu/gnu/doc/html/cvs_7.html#SEC37 31[up]: /help?cmd=update 32