Accidentally deleting or writing over a file is always a concern when working on computer systems. The various editors you may use in the Linux Lab have undo features and also may provide backup copies of edited files. Documentation for the various editors used in the lab may be found through the use of the "man" and "info" commands as well as through Internet searches. Versioning systems such as CVS and RCS are also available for use in the Linux Lab if you desire to learn about them and use them.
Another source for recovering a previous version of a file or a deleted file is through the backup copies of files that are made on a daily basis. Daily, a copy of the contents of your home directory is made early in the morning. If you delete a file, and want to get the version that you had the previous day restored, you may copy the previous day's file from the directory structure /backup/. The command to do so might look like:
cp /backup/aaa98001/cs124/assign3.cpp ~/cs124
if "aa98001" is the name of your home directory (which would also be your BYU-Idaho email address) and you had a directory named "cs124" that you kept all your work in for CS 124.
If you need to recover a file, or a version of a file that was deleted prior to the current day, then look in the /backup/incremental/ structure for the version of the file you want. Files that are found in the /backup/incremental/ directory structure will have extension on them of ".Mon.bak", ".Tue.bak", etc. The incremental backup directories allow for up to seven versions of any one file. However, if you always edit the file on the same day of the week you will only have access to one previous version of the file other than the one in /backup/. Additionally, previous versions of files will only be kept on the system for about two months.
To recover a file from the /backup/incremental directory structure the command might be:
In addition to the /backup and /backup/incremental directory structures, one additional backup directory structure is provided. This is /backup/archive. Under /backup/archive/ you will find the most recent copy of any file that was ever placed into the /backup/ directory structure, with the exception of browser cache files and some other temporary system files.