Documentation / git-fsck.txton commit verify-tag: drop signal.h include (96728b2)
   1git-fsck(1)
   2===========
   3
   4NAME
   5----
   6git-fsck - Verifies the connectivity and validity of the objects in the database
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git fsck' [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
  13         [--[no-]full] [--strict] [--verbose] [--lost-found]
  14         [--[no-]dangling] [--[no-]progress] [--connectivity-only]
  15         [--[no-]name-objects] [<object>*]
  16
  17DESCRIPTION
  18-----------
  19Verifies the connectivity and validity of the objects in the database.
  20
  21OPTIONS
  22-------
  23<object>::
  24        An object to treat as the head of an unreachability trace.
  25+
  26If no objects are given, 'git fsck' defaults to using the
  27index file, all SHA-1 references in `refs` namespace, and all reflogs
  28(unless --no-reflogs is given) as heads.
  29
  30--unreachable::
  31        Print out objects that exist but that aren't reachable from any
  32        of the reference nodes.
  33
  34--[no-]dangling::
  35        Print objects that exist but that are never 'directly' used (default).
  36        `--no-dangling` can be used to omit this information from the output.
  37
  38--root::
  39        Report root nodes.
  40
  41--tags::
  42        Report tags.
  43
  44--cache::
  45        Consider any object recorded in the index also as a head node for
  46        an unreachability trace.
  47
  48--no-reflogs::
  49        Do not consider commits that are referenced only by an
  50        entry in a reflog to be reachable.  This option is meant
  51        only to search for commits that used to be in a ref, but
  52        now aren't, but are still in that corresponding reflog.
  53
  54--full::
  55        Check not just objects in GIT_OBJECT_DIRECTORY
  56        ($GIT_DIR/objects), but also the ones found in alternate
  57        object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES
  58        or $GIT_DIR/objects/info/alternates,
  59        and in packed Git archives found in $GIT_DIR/objects/pack
  60        and corresponding pack subdirectories in alternate
  61        object pools.  This is now default; you can turn it off
  62        with --no-full.
  63
  64--connectivity-only::
  65        Check only the connectivity of reachable objects, making sure
  66        that any objects referenced by a reachable tag, commit, or tree
  67        is present. This speeds up the operation by avoiding reading
  68        blobs entirely (though it does still check that referenced blobs
  69        exist). This will detect corruption in commits and trees, but
  70        not do any semantic checks (e.g., for format errors). Corruption
  71        in blob objects will not be detected at all.
  72+
  73Unreachable tags, commits, and trees will also be accessed to find the
  74tips of dangling segments of history. Use `--no-dangling` if you don't
  75care about this output and want to speed it up further.
  76
  77--strict::
  78        Enable more strict checking, namely to catch a file mode
  79        recorded with g+w bit set, which was created by older
  80        versions of Git.  Existing repositories, including the
  81        Linux kernel, Git itself, and sparse repository have old
  82        objects that triggers this check, but it is recommended
  83        to check new projects with this flag.
  84
  85--verbose::
  86        Be chatty.
  87
  88--lost-found::
  89        Write dangling objects into .git/lost-found/commit/ or
  90        .git/lost-found/other/, depending on type.  If the object is
  91        a blob, the contents are written into the file, rather than
  92        its object name.
  93
  94--name-objects::
  95        When displaying names of reachable objects, in addition to the
  96        SHA-1 also display a name that describes *how* they are reachable,
  97        compatible with linkgit:git-rev-parse[1], e.g.
  98        `HEAD@{1234567890}~25^2:src/`.
  99
 100--[no-]progress::
 101        Progress status is reported on the standard error stream by
 102        default when it is attached to a terminal, unless
 103        --no-progress or --verbose is specified. --progress forces
 104        progress status even if the standard error stream is not
 105        directed to a terminal.
 106
 107DISCUSSION
 108----------
 109
 110git-fsck tests SHA-1 and general object sanity, and it does full tracking
 111of the resulting reachability and everything else. It prints out any
 112corruption it finds (missing or bad objects), and if you use the
 113`--unreachable` flag it will also print out objects that exist but that
 114aren't reachable from any of the specified head nodes (or the default
 115set, as mentioned above).
 116
 117Any corrupt objects you will have to find in backups or other archives
 118(i.e., you can just remove them and do an 'rsync' with some other site in
 119the hopes that somebody else has the object you have corrupted).
 120
 121If core.commitGraph is true, the commit-graph file will also be inspected
 122using 'git commit-graph verify'. See linkgit:git-commit-graph[1].
 123
 124Extracted Diagnostics
 125---------------------
 126
 127expect dangling commits - potential heads - due to lack of head information::
 128        You haven't specified any nodes as heads so it won't be
 129        possible to differentiate between un-parented commits and
 130        root nodes.
 131
 132missing sha1 directory '<dir>'::
 133        The directory holding the sha1 objects is missing.
 134
 135unreachable <type> <object>::
 136        The <type> object <object>, isn't actually referred to directly
 137        or indirectly in any of the trees or commits seen. This can
 138        mean that there's another root node that you're not specifying
 139        or that the tree is corrupt. If you haven't missed a root node
 140        then you might as well delete unreachable nodes since they
 141        can't be used.
 142
 143missing <type> <object>::
 144        The <type> object <object>, is referred to but isn't present in
 145        the database.
 146
 147dangling <type> <object>::
 148        The <type> object <object>, is present in the database but never
 149        'directly' used. A dangling commit could be a root node.
 150
 151hash mismatch <object>::
 152        The database has an object whose hash doesn't match the
 153        object database value.
 154        This indicates a serious data integrity problem.
 155
 156Environment Variables
 157---------------------
 158
 159GIT_OBJECT_DIRECTORY::
 160        used to specify the object database root (usually $GIT_DIR/objects)
 161
 162GIT_INDEX_FILE::
 163        used to specify the index file of the index
 164
 165GIT_ALTERNATE_OBJECT_DIRECTORIES::
 166        used to specify additional object database roots (usually unset)
 167
 168GIT
 169---
 170Part of the linkgit:git[1] suite