git-reflog - Manage reflog information
git reflog <subcommand> <options>
The command takes various subcommands, and different options depending on the subcommand: git reflog [show] [log-options] [<ref>] git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run] [--verbose] [--all | <refs>...] git reflog delete [--rewrite] [--updateref] [--dry-run] [--verbose] ref@{specifier}... git reflog exists <ref> Reference logs, or "reflogs", record when the tips of branches and other references were updated in the local repository. Reflogs are useful in various Git commands, to specify the old value of a reference. For example, HEAD@{2} means "where HEAD used to be two moves ago", master@{one.week.ago} means "where master used to point to one week ago in this local repository", and so on. See gitrevisions(7) for more details. This command manages the information recorded in the reflogs. The "show" subcommand (which is also the default, in the absence of any subcommands) shows the log of the reference provided in the command-line (or HEAD, by default). The reflog covers all recent actions, and in addition the HEAD reflog records branch switching. git reflog show is an alias for git log -g --abbrev-commit --pretty=oneline; see git-log(1) for more information. The "expire" subcommand prunes older reflog entries. Entries older than expire time, or entries older than expire-unreachable time and not reachable from the current tip, are removed from the reflog. This is typically not used directly by end users --- instead, see git-gc(1). The "delete" subcommand deletes single entries from the reflog. Its argument must be an exact entry (e.g. "git reflog delete master@{2}"). This subcommand is also typically not used directly by end users. The "exists" subcommand checks whether a ref has a reflog. It exits with zero status if the reflog exists, and non-zero status if it does not.
Options for show git reflog show accepts any of the options accepted by git log. Options for expire --all Process the reflogs of all references. --expire=<time> Prune entries older than the specified time. If this option is not specified, the expiration time is taken from the configuration setting gc.reflogExpire, which in turn defaults to 90 days. --expire=all prunes entries regardless of their age; --expire=never turns off pruning of reachable entries (but see --expire-unreachable). --expire-unreachable=<time> Prune entries older than <time> that are not reachable from the current tip of the branch. If this option is not specified, the expiration time is taken from the configuration setting gc.reflogExpireUnreachable, which in turn defaults to 30 days. --expire-unreachable=all prunes unreachable entries regardless of their age; --expire-unreachable=never turns off early pruning of unreachable entries (but see --expire). --updateref Update the reference to the value of the top reflog entry (i.e. <ref>@{0}) if the previous top entry was pruned. (This option is ignored for symbolic references.) --rewrite If a reflog entry's predecessor is pruned, adjust its "old" SHA-1 to be equal to the "new" SHA-1 field of the entry that now precedes it. --stale-fix Prune any reflog entries that point to "broken commits". A broken commit is a commit that is not reachable from any of the reference tips and that refers, directly or indirectly, to a missing commit, tree, or blob object. This computation involves traversing all the reachable objects, i.e. it has the same cost as git prune. It is primarily intended to fix corruption caused by garbage collecting using older versions of Git, which didn't protect objects referred to by reflogs. -n, --dry-run Do not actually prune any entries; just show what would have been pruned. --verbose Print extra information on screen. Options for delete git reflog delete accepts options --updateref, --rewrite, -n, --dry-run, and --verbose, with the same meanings as when they are used with expire.
Part of the git(1) suite
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.