SYNOPSIS
--------
+[verse]
frontend | 'git fast-import' [options]
DESCRIPTION
OPTIONS
-------
---date-format=<fmt>::
- Specify the type of dates the frontend will supply to
- fast-import within `author`, `committer` and `tagger` commands.
- See ``Date Formats'' below for details about which formats
- are supported, and their syntax.
--force::
Force updating modified existing branches, even if doing
so would cause commits to be lost (as the new commit does
not contain the old commit).
---max-pack-size=<n>::
- Maximum size of each output packfile.
- The default is unlimited.
+--quiet::
+ Disable all non-fatal output, making fast-import silent when it
+ is successful. This option disables the output shown by
+ \--stats.
---big-file-threshold=<n>::
- Maximum size of a blob that fast-import will attempt to
- create a delta for, expressed in bytes. The default is 512m
- (512 MiB). Some importers may wish to lower this on systems
- with constrained memory.
+--stats::
+ Display some basic statistics about the objects fast-import has
+ created, the packfiles they were stored into, and the
+ memory used by fast-import during this run. Showing this output
+ is currently the default, but can be disabled with \--quiet.
---depth=<n>::
- Maximum delta depth, for blob and tree deltification.
- Default is 10.
+Options for Frontends
+~~~~~~~~~~~~~~~~~~~~~
---active-branches=<n>::
- Maximum number of branches to maintain active at once.
- See ``Memory Utilization'' below for details. Default is 5.
+--cat-blob-fd=<fd>::
+ Write responses to `cat-blob` and `ls` queries to the
+ file descriptor <fd> instead of `stdout`. Allows `progress`
+ output intended for the end-user to be separated from other
+ output.
+
+--date-format=<fmt>::
+ Specify the type of dates the frontend will supply to
+ fast-import within `author`, `committer` and `tagger` commands.
+ See ``Date Formats'' below for details about which formats
+ are supported, and their syntax.
+
+--done::
+ Terminate with error if there is no `done` command at the end of
+ the stream. This option might be useful for detecting errors
+ that cause the frontend to terminate before it has started to
+ write a stream.
+
+Locations of Marks Files
+~~~~~~~~~~~~~~~~~~~~~~~~
--export-marks=<file>::
Dumps the internal marks table to <file> when complete.
Like --import-marks but instead of erroring out, silently
skips the file if it does not exist.
---relative-marks::
- After specifying --relative-marks= the paths specified
+--[no-]relative-marks::
+ After specifying --relative-marks the paths specified
with --import-marks= and --export-marks= are relative
to an internal directory in the current repository.
In git-fast-import this means that the paths are relative
to the .git/info/fast-import directory. However, other
importers may use a different location.
++
+Relative and non-relative marks may be combined by interweaving
+--(no-)-relative-marks with the --(import|export)-marks= options.
---no-relative-marks::
- Negates a previous --relative-marks. Allows for combining
- relative and non-relative marks by interweaving
- --(no-)-relative-marks= with the --(import|export)-marks=
- options.
+Performance and Compression Tuning
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
---cat-blob-fd=<fd>::
- Specify the file descriptor that will be written to
- when the `cat-blob` command is encountered in the stream.
- The default behaviour is to write to `stdout`.
+--active-branches=<n>::
+ Maximum number of branches to maintain active at once.
+ See ``Memory Utilization'' below for details. Default is 5.
+
+--big-file-threshold=<n>::
+ Maximum size of a blob that fast-import will attempt to
+ create a delta for, expressed in bytes. The default is 512m
+ (512 MiB). Some importers may wish to lower this on systems
+ with constrained memory.
+
+--depth=<n>::
+ Maximum delta depth, for blob and tree deltification.
+ Default is 10.
--export-pack-edges=<file>::
After creating a packfile, print a line of data to
as these commits can be used as edge points during calls
to 'git pack-objects'.
---quiet::
- Disable all non-fatal output, making fast-import silent when it
- is successful. This option disables the output shown by
- \--stats.
-
---stats::
- Display some basic statistics about the objects fast-import has
- created, the packfiles they were stored into, and the
- memory used by fast-import during this run. Showing this output
- is currently the default, but can be disabled with \--quiet.
+--max-pack-size=<n>::
+ Maximum size of each output packfile.
+ The default is unlimited.
Performance
Ruby is being used.
fast-import is very strict about its input. Where we say SP below we mean
-*exactly* one space. Likewise LF means one (and only one) linefeed.
+*exactly* one space. Likewise LF means one (and only one) linefeed
+and HT one (and only one) horizontal tab.
Supplying additional whitespace characters will cause unexpected
results, such as branch names or file names with leading or trailing
spaces in their name, or early termination of fast-import when it encounters
standard output. This command is optional and is not needed
to perform an import.
+`done`::
+ Marks the end of the stream. This command is optional
+ unless the `done` feature was requested using the
+ `--done` command line option or `feature done` command.
+
`cat-blob`::
Causes fast-import to print a blob in 'cat-file --batch'
format to the file descriptor set with `--cat-blob-fd` or
`stdout` if unspecified.
+`ls`::
+ Causes fast-import to print a line describing a directory
+ entry in 'ls-tree' format to the file descriptor set with
+ `--cat-blob-fd` or `stdout` if unspecified.
+
`feature`::
Require that fast-import supports the specified feature, or
abort if it does not.
Here `<name>` is the person's display name (for example
``Com M Itter'') and `<email>` is the person's email address
-(``cm@example.com''). `LT` and `GT` are the literal less-than (\x3c)
+(``\cm@example.com''). `LT` and `GT` are the literal less-than (\x3c)
and greater-than (\x3e) symbols. These are required to delimit
the email address from the other fields in the line. Note that
-`<name>` is free-form and may contain any sequence of bytes, except
-`LT` and `LF`. It is typically UTF-8 encoded.
+`<name>` and `<email>` are free-form and may contain any sequence
+of bytes, except `LT`, `GT` and `LF`. `<name>` is typically UTF-8 encoded.
The time of the change is specified by `<when>` using the date format
that was selected by the \--date-format=<fmt> command line option.
^^^^^^
The `from` command is used to specify the commit to initialize
this branch from. This revision will be the first ancestor of the
-new commit.
+new commit. The state of the tree built at this commit will begin
+with the state at the `from` commit, and be altered by the content
+modifications in this commit.
Omitting the `from` command in the first commit of a new branch
will cause fast-import to create that commit with no ancestor. This
----
from refs/heads/branch^0
----
-The `{caret}0` suffix is necessary as fast-import does not permit a branch to
+The `^0` suffix is necessary as fast-import does not permit a branch to
start from itself, and the branch is created in memory before the
-`from` command is even read from the input. Adding `{caret}0` will force
+`from` command is even read from the input. Adding `^0` will force
fast-import to resolve the commit through Git's revision parsing library,
rather than its internal branch table, thereby loading in the
existing value of the branch.
`merge`
^^^^^^^
-Includes one additional ancestor commit. If the `from` command is
+Includes one additional ancestor commit. The additional ancestry
+link does not change the way the tree state is built at this commit.
+If the `from` command is
omitted when creating a new branch, the first `merge` commit will be
the first ancestor of the current commit, and the branch will start
out with no files. An unlimited number of `merge` commands per
slash `/`), may contain any byte other than `LF`, and must not
start with double quote (`"`).
-If an `LF` or double quote must be encoded into `<path>` shell-style
-quoting should be used, e.g. `"path/with\n and \" in it"`.
+A path can use C-style string quoting; this is accepted in all cases
+and mandatory if the filename starts with double quote or contains
+`LF`. In C-style quoting, the complete name should be surrounded with
+double quotes, and any `LF`, backslash, or double quote characters
+must be escaped by preceding them with a backslash (e.g.,
+`"path/with\n, \\ and \" in it"`).
The value of `<path>` must be in canonical form. That is it must not:
`notemodify`
^^^^^^^^^^^^
-Included in a `commit` command to add a new note (annotating a given
-commit) or change the content of an existing note. This command has
-two different means of specifying the content of the note.
+Included in a `commit` `<notes_ref>` command to add a new note
+annotating a `<committish>` or change this annotation contents.
+Internally it is similar to filemodify 100644 on `<committish>`
+path (maybe split into subdirectories). It's not advised to
+use any other commands to write to the `<notes_ref>` tree except
+`filedeleteall` to delete all existing notes in this tree.
+This command has two different means of specifying the content
+of the note.
External data format::
The data content for the note was already supplied by a prior
accepted. In particular, the `cat-blob` command can be used in the
middle of a commit but not in the middle of a `data` command.
+See ``Responses To Commands'' below for details about how to read
+this output safely.
+
+`ls`
+~~~~
+Prints information about the object at a path to a file descriptor
+previously arranged with the `--cat-blob-fd` argument. This allows
+printing a blob from the active commit (with `cat-blob`) or copying a
+blob or tree from a previous commit for use in the current one (with
+`filemodify`).
+
+The `ls` command can be used anywhere in the stream that comments are
+accepted, including the middle of a commit.
+
+Reading from the active commit::
+ This form can only be used in the middle of a `commit`.
+ The path names a directory entry within fast-import's
+ active commit. The path must be quoted in this case.
++
+....
+ 'ls' SP <path> LF
+....
+
+Reading from a named tree::
+ The `<dataref>` can be a mark reference (`:<idnum>`) or the
+ full 40-byte SHA-1 of a Git tag, commit, or tree object,
+ preexisting or waiting to be written.
+ The path is relative to the top level of the tree
+ named by `<dataref>`.
++
+....
+ 'ls' SP <dataref> SP <path> LF
+....
+
+See `filemodify` above for a detailed description of `<path>`.
+
+Output uses the same format as `git ls-tree <tree> -- <path>`:
+
+====
+ <mode> SP ('blob' | 'tree' | 'commit') SP <dataref> HT <path> LF
+====
+
+The <dataref> represents the blob, tree, or commit object at <path>
+and can be used in later 'cat-blob', 'filemodify', or 'ls' commands.
+
+If there is no file or subtree at that path, 'git fast-import' will
+instead report
+
+====
+ missing SP <path> LF
+====
+
+See ``Responses To Commands'' below for details about how to read
+this output safely.
+
`feature`
~~~~~~~~~
Require that fast-import supports the specified feature, or abort if
(see OPTIONS, above).
import-marks::
+import-marks-if-exists::
Like --import-marks except in two respects: first, only one
- "feature import-marks" command is allowed per stream;
- second, an --import-marks= command-line option overrides
- any "feature import-marks" command in the stream.
+ "feature import-marks" or "feature import-marks-if-exists"
+ command is allowed per stream; second, an --import-marks=
+ or --import-marks-if-exists command-line option overrides
+ any of these "feature" commands in the stream; third,
+ "feature import-marks-if-exists" like a corresponding
+ command-line option silently skips a nonexistent file.
cat-blob::
- Ignored. Versions of fast-import not supporting the
- "cat-blob" command will exit with a message indicating so.
+ls::
+ Require that the backend support the 'cat-blob' or 'ls' command.
+ Versions of fast-import not supporting the specified command
+ will exit with a message indicating so.
This lets the import error out early with a clear message,
rather than wasting time on the early part of an import
before the unsupported command is detected.
Versions of fast-import not supporting notes will exit
with a message indicating so.
+done::
+ Error out if the stream ends without a 'done' command.
+ Without this feature, errors causing the frontend to end
+ abruptly at a convenient point in the stream can go
+ undetected. This may occur, for example, if an import
+ front end dies in mid-operation without emitting SIGTERM
+ or SIGKILL at its subordinate git fast-import instance.
`option`
~~~~~~~~
* cat-blob-fd
* force
+`done`
+~~~~~~
+If the `done` feature is not in use, treated as if EOF was read.
+This can be used to tell fast-import to finish early.
+
+If the `--done` command line option or `feature done` command is
+in use, the `done` command is mandatory and marks the end of the
+stream.
+
+Responses To Commands
+---------------------
+New objects written by fast-import are not available immediately.
+Most fast-import commands have no visible effect until the next
+checkpoint (or completion). The frontend can send commands to
+fill fast-import's input pipe without worrying about how quickly
+they will take effect, which improves performance by simplifying
+scheduling.
+
+For some frontends, though, it is useful to be able to read back
+data from the current repository as it is being updated (for
+example when the source material describes objects in terms of
+patches to be applied to previously imported objects). This can
+be accomplished by connecting the frontend and fast-import via
+bidirectional pipes:
+
+====
+ mkfifo fast-import-output
+ frontend <fast-import-output |
+ git fast-import >fast-import-output
+====
+
+A frontend set up this way can use `progress`, `ls`, and `cat-blob`
+commands to read information from the import in progress.
+
+To avoid deadlock, such frontends must completely consume any
+pending output from `progress`, `ls`, and `cat-blob` before
+performing writes to fast-import that might block.
+
Crash Reports
-------------
If fast-import is supplied invalid input it will terminate with a
import in progress, at the cost of some added running time and worse
compression.
-Author
-------
-Written by Shawn O. Pearce <spearce@spearce.org>.
-
-Documentation
---------------
-Documentation by Shawn O. Pearce <spearce@spearce.org>.
-
GIT
---
Part of the linkgit:git[1] suite