Documentation/gitcli.txt - jrn/git - Git at Google

 gitcli(7)
 =========

 NAME
 ----
 gitcli - Git command line interface and conventions

 SYNOPSIS
 --------
 gitcli


 DESCRIPTION
 -----------

 This manual describes the convention used throughout Git CLI.

 Many commands take revisions (most often "commits", but sometimes
 "tree-ish", depending on the context and command) and paths as their
 arguments.  Here are the rules:

  * Revisions come first and then paths.
    E.g. in `git diff v1.0 v2.0 arch/x86 include/asm-x86`,
    `v1.0` and `v2.0` are revisions and `arch/x86` and `include/asm-x86`
    are paths.

  * When an argument can be misunderstood as either a revision or a path,
    they can be disambiguated by placing `--` between them.
    E.g. `git diff -- HEAD` is, "I have a file called HEAD in my work
    tree.  Please show changes between the version I staged in the index
    and what I have in the work tree for that file". not "show difference
    between the HEAD commit and the work tree as a whole".  You can say
    `git diff HEAD --` to ask for the latter.

  * Without disambiguating `--`, Git makes a reasonable guess, but errors
    out and asking you to disambiguate when ambiguous.  E.g. if you have a
    file called HEAD in your work tree, `git diff HEAD` is ambiguous, and
    you have to say either `git diff HEAD --` or `git diff -- HEAD` to
    disambiguate.
 +
 When writing a script that is expected to handle random user-input, it is
 a good practice to make it explicit which arguments are which by placing
 disambiguating `--` at appropriate places.

  * Many commands allow wildcards in paths, but you need to protect
    them from getting globbed by the shell.  These two mean different
    things:
 +
 --------------------------------
 $ git checkout -- *.c
 $ git checkout -- \*.c
 --------------------------------
 +
 The former lets your shell expand the fileglob, and you are asking
 the dot-C files in your working tree to be overwritten with the version
 in the index.  The latter passes the `*.c` to Git, and you are asking
 the paths in the index that match the pattern to be checked out to your
 working tree.  After running `git add hello.c; rm hello.c`, you will _not_
 see `hello.c` in your working tree with the former, but with the latter
 you will.

 Here are the rules regarding the "flags" that you should follow when you are
 scripting Git:

  * it's preferred to use the non dashed form of Git commands, which means that
    you should prefer `git foo` to `git-foo`.

  * splitting short options to separate words (prefer `git foo -a -b`
    to `git foo -ab`, the latter may not even work).

  * when a command line option takes an argument, use the 'sticked' form.  In
    other words, write `git foo -oArg` instead of `git foo -o Arg` for short
    options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
    for long options.  An option that takes optional option-argument must be
    written in the 'sticked' form.

  * when you give a revision parameter to a command, make sure the parameter is
    not ambiguous with a name of a file in the work tree.  E.g. do not write
    `git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
    if you happen to have a file called `HEAD` in the work tree.

  * many commands allow a long option "--option" to be abbreviated
    only to their unique prefix (e.g. if there is no other option
    whose name begins with "opt", you may be able to spell "--opt" to
    invoke the "--option" flag), but you should fully spell them out
    when writing your scripts; later versions of Git may introduce a
    new option whose name shares the same prefix, e.g. "--optimize",
    to make a short prefix that used to be unique no longer unique.


 ENHANCED OPTION PARSER
 ----------------------
 From the Git 1.5.4 series and further, many Git commands (not all of them at the
 time of the writing though) come with an enhanced option parser.

 Here is a list of the facilities provided by this option parser.


 Magic Options
 ~~~~~~~~~~~~~
 Commands which have the enhanced option parser activated all understand a
 couple of magic command line options:

 -h::
 	gives a pretty printed usage of the command.
 +
 ---------------------------------------------
 $ git describe -h
 usage: git describe [options] <committish>*
    or: git describe [options] --dirty

     --contains            find the tag that comes after the commit
     --debug               debug search strategy on stderr
     --all                 use any ref
     --tags                use any tag, even unannotated
     --long                always use long format
     --abbrev[=<n>]        use <n> digits to display SHA-1s
 ---------------------------------------------

 --help-all::
 	Some Git commands take options that are only used for plumbing or that
 	are deprecated, and such options are hidden from the default usage. This
 	option gives the full list of options.


 Negating options
 ~~~~~~~~~~~~~~~~
 Options with long option names can be negated by prefixing `--no-`. For
 example, `git branch` has the option `--track` which is 'on' by default. You
 can use `--no-track` to override that behaviour. The same goes for `--color`
 and `--no-color`.


 Aggregating short options
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 Commands that support the enhanced option parser allow you to aggregate short
 options. This means that you can for example use `git rm -rf` or
 `git clean -fdx`.


 Abbreviating long options
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 Commands that support the enhanced option parser accepts unique
 prefix of a long option as if it is fully spelled out, but use this
 with a caution.  For example, `git commit --amen` behaves as if you
 typed `git commit --amend`, but that is true only until a later version
 of Git introduces another option that shares the same prefix,
 e.g `git commit --amenity" option.


 Separating argument from the option
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 You can write the mandatory option parameter to an option as a separate
 word on the command line.  That means that all the following uses work:

 ----------------------------
 $ git foo --long-opt=Arg
 $ git foo --long-opt Arg
 $ git foo -oArg
 $ git foo -o Arg
 ----------------------------

 However, this is *NOT* allowed for switches with an optional value, where the
 'sticked' form must be used:
 ----------------------------
 $ git describe --abbrev HEAD     # correct
 $ git describe --abbrev=10 HEAD  # correct
 $ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
 ----------------------------


 NOTES ON FREQUENTLY CONFUSED OPTIONS
 ------------------------------------

 Many commands that can work on files in the working tree
 and/or in the index can take `--cached` and/or `--index`
 options.  Sometimes people incorrectly think that, because
 the index was originally called cache, these two are
 synonyms.  They are *not* -- these two options mean very
 different things.

  * The `--cached` option is used to ask a command that
    usually works on files in the working tree to *only* work
    with the index.  For example, `git grep`, when used
    without a commit to specify from which commit to look for
    strings in, usually works on files in the working tree,
    but with the `--cached` option, it looks for strings in
    the index.

  * The `--index` option is used to ask a command that
    usually works on files in the working tree to *also*
    affect the index.  For example, `git stash apply` usually
    merges changes recorded in a stash to the working tree,
    but with the `--index` option, it also merges changes to
    the index as well.

 `git apply` command can be used with `--cached` and
 `--index` (but not at the same time).  Usually the command
 only affects the files in the working tree, but with
 `--index`, it patches both the files and their index
 entries, and with `--cached`, it modifies only the index
 entries.

 See also http://marc.info/?l=git&m=116563135620359 and
 http://marc.info/?l=git&m=119150393620273 for further
 information.

 GIT
 ---
 Part of the linkgit:git[1] suite
	gitcli(7)
	=========

	NAME
	----
	gitcli - Git command line interface and conventions

	SYNOPSIS
	--------
	gitcli


	DESCRIPTION
	-----------

	This manual describes the convention used throughout Git CLI.

	Many commands take revisions (most often "commits", but sometimes
	"tree-ish", depending on the context and command) and paths as their
	arguments. Here are the rules:

	* Revisions come first and then paths.
	E.g. in `git diff v1.0 v2.0 arch/x86 include/asm-x86`,
	`v1.0` and `v2.0` are revisions and `arch/x86` and `include/asm-x86`
	are paths.

	* When an argument can be misunderstood as either a revision or a path,
	they can be disambiguated by placing `--` between them.
	E.g. `git diff -- HEAD` is, "I have a file called HEAD in my work
	tree. Please show changes between the version I staged in the index
	and what I have in the work tree for that file". not "show difference
	between the HEAD commit and the work tree as a whole". You can say
	`git diff HEAD --` to ask for the latter.

	* Without disambiguating `--`, Git makes a reasonable guess, but errors
	out and asking you to disambiguate when ambiguous. E.g. if you have a
	file called HEAD in your work tree, `git diff HEAD` is ambiguous, and
	you have to say either `git diff HEAD --` or `git diff -- HEAD` to
	disambiguate.
	+
	When writing a script that is expected to handle random user-input, it is
	a good practice to make it explicit which arguments are which by placing
	disambiguating `--` at appropriate places.

	* Many commands allow wildcards in paths, but you need to protect
	them from getting globbed by the shell. These two mean different
	things:
	+
	--------------------------------
	$ git checkout -- *.c
	$ git checkout -- \*.c
	--------------------------------
	+
	The former lets your shell expand the fileglob, and you are asking
	the dot-C files in your working tree to be overwritten with the version
	in the index. The latter passes the `*.c` to Git, and you are asking
	the paths in the index that match the pattern to be checked out to your
	working tree. After running `git add hello.c; rm hello.c`, you will _not_
	see `hello.c` in your working tree with the former, but with the latter
	you will.

	Here are the rules regarding the "flags" that you should follow when you are
	scripting Git:

	* it's preferred to use the non dashed form of Git commands, which means that
	you should prefer `git foo` to `git-foo`.

	* splitting short options to separate words (prefer `git foo -a -b`
	to `git foo -ab`, the latter may not even work).

	* when a command line option takes an argument, use the 'sticked' form. In
	other words, write `git foo -oArg` instead of `git foo -o Arg` for short
	options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
	for long options. An option that takes optional option-argument must be
	written in the 'sticked' form.

	* when you give a revision parameter to a command, make sure the parameter is
	not ambiguous with a name of a file in the work tree. E.g. do not write
	`git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
	if you happen to have a file called `HEAD` in the work tree.

	* many commands allow a long option "--option" to be abbreviated
	only to their unique prefix (e.g. if there is no other option
	whose name begins with "opt", you may be able to spell "--opt" to
	invoke the "--option" flag), but you should fully spell them out
	when writing your scripts; later versions of Git may introduce a
	new option whose name shares the same prefix, e.g. "--optimize",
	to make a short prefix that used to be unique no longer unique.


	ENHANCED OPTION PARSER
	----------------------
	From the Git 1.5.4 series and further, many Git commands (not all of them at the
	time of the writing though) come with an enhanced option parser.

	Here is a list of the facilities provided by this option parser.


	Magic Options
	~~~~~~~~~~~~~
	Commands which have the enhanced option parser activated all understand a
	couple of magic command line options:

	-h::
	gives a pretty printed usage of the command.
	+
	---------------------------------------------
	$ git describe -h
	usage: git describe [options] <committish>*
	or: git describe [options] --dirty

	--contains find the tag that comes after the commit
	--debug debug search strategy on stderr
	--all use any ref
	--tags use any tag, even unannotated
	--long always use long format
	--abbrev[=<n>] use <n> digits to display SHA-1s
	---------------------------------------------

	--help-all::
	Some Git commands take options that are only used for plumbing or that
	are deprecated, and such options are hidden from the default usage. This
	option gives the full list of options.


	Negating options
	~~~~~~~~~~~~~~~~
	Options with long option names can be negated by prefixing `--no-`. For
	example, `git branch` has the option `--track` which is 'on' by default. You
	can use `--no-track` to override that behaviour. The same goes for `--color`
	and `--no-color`.


	Aggregating short options
	~~~~~~~~~~~~~~~~~~~~~~~~~
	Commands that support the enhanced option parser allow you to aggregate short
	options. This means that you can for example use `git rm -rf` or
	`git clean -fdx`.


	Abbreviating long options
	~~~~~~~~~~~~~~~~~~~~~~~~~
	Commands that support the enhanced option parser accepts unique
	prefix of a long option as if it is fully spelled out, but use this
	with a caution. For example, `git commit --amen` behaves as if you
	typed `git commit --amend`, but that is true only until a later version
	of Git introduces another option that shares the same prefix,
	e.g `git commit --amenity" option.


	Separating argument from the option
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	You can write the mandatory option parameter to an option as a separate
	word on the command line. That means that all the following uses work:

	----------------------------
	$ git foo --long-opt=Arg
	$ git foo --long-opt Arg
	$ git foo -oArg
	$ git foo -o Arg
	----------------------------

	However, this is NOT allowed for switches with an optional value, where the
	'sticked' form must be used:
	----------------------------
	$ git describe --abbrev HEAD # correct
	$ git describe --abbrev=10 HEAD # correct
	$ git describe --abbrev 10 HEAD # NOT WHAT YOU MEANT
	----------------------------


	NOTES ON FREQUENTLY CONFUSED OPTIONS
	------------------------------------

	Many commands that can work on files in the working tree
	and/or in the index can take `--cached` and/or `--index`
	options. Sometimes people incorrectly think that, because
	the index was originally called cache, these two are
	synonyms. They are not -- these two options mean very
	different things.

	* The `--cached` option is used to ask a command that
	usually works on files in the working tree to only work
	with the index. For example, `git grep`, when used
	without a commit to specify from which commit to look for
	strings in, usually works on files in the working tree,
	but with the `--cached` option, it looks for strings in
	the index.

	* The `--index` option is used to ask a command that
	usually works on files in the working tree to also
	affect the index. For example, `git stash apply` usually
	merges changes recorded in a stash to the working tree,
	but with the `--index` option, it also merges changes to
	the index as well.

	`git apply` command can be used with `--cached` and
	`--index` (but not at the same time). Usually the command
	only affects the files in the working tree, but with
	`--index`, it patches both the files and their index
	entries, and with `--cached`, it modifies only the index
	entries.

	See also http://marc.info/?l=git&m=116563135620359 and
	http://marc.info/?l=git&m=119150393620273 for further
	information.

	GIT
	---
	Part of the linkgit:git[1] suite