Documentation / gitcli.txton commit Merge branch 'rs/sort-oid-array-thread-safe' (2743b61)
   1gitcli(7)
   2=========
   3
   4NAME
   5----
   6gitcli - Git command-line interface and conventions
   7
   8SYNOPSIS
   9--------
  10gitcli
  11
  12
  13DESCRIPTION
  14-----------
  15
  16This manual describes the convention used throughout Git CLI.
  17
  18Many commands take revisions (most often "commits", but sometimes
  19"tree-ish", depending on the context and command) and paths as their
  20arguments.  Here are the rules:
  21
  22 * Revisions come first and then paths.
  23   E.g. in `git diff v1.0 v2.0 arch/x86 include/asm-x86`,
  24   `v1.0` and `v2.0` are revisions and `arch/x86` and `include/asm-x86`
  25   are paths.
  26
  27 * When an argument can be misunderstood as either a revision or a path,
  28   they can be disambiguated by placing `--` between them.
  29   E.g. `git diff -- HEAD` is, "I have a file called HEAD in my work
  30   tree.  Please show changes between the version I staged in the index
  31   and what I have in the work tree for that file", not "show difference
  32   between the HEAD commit and the work tree as a whole".  You can say
  33   `git diff HEAD --` to ask for the latter.
  34
  35 * Without disambiguating `--`, Git makes a reasonable guess, but errors
  36   out and asking you to disambiguate when ambiguous.  E.g. if you have a
  37   file called HEAD in your work tree, `git diff HEAD` is ambiguous, and
  38   you have to say either `git diff HEAD --` or `git diff -- HEAD` to
  39   disambiguate.
  40
  41 * Because `--` disambiguates revisions and paths in some commands, it
  42   cannot be used for those commands to separate options and revisions.
  43   You can use `--end-of-options` for this (it also works for commands
  44   that do not distinguish between revisions in paths, in which case it
  45   is simply an alias for `--`).
  46+
  47When writing a script that is expected to handle random user-input, it is
  48a good practice to make it explicit which arguments are which by placing
  49disambiguating `--` at appropriate places.
  50
  51 * Many commands allow wildcards in paths, but you need to protect
  52   them from getting globbed by the shell.  These two mean different
  53   things:
  54+
  55--------------------------------
  56$ git restore *.c
  57$ git restore \*.c
  58--------------------------------
  59+
  60The former lets your shell expand the fileglob, and you are asking
  61the dot-C files in your working tree to be overwritten with the version
  62in the index.  The latter passes the `*.c` to Git, and you are asking
  63the paths in the index that match the pattern to be checked out to your
  64working tree.  After running `git add hello.c; rm hello.c`, you will _not_
  65see `hello.c` in your working tree with the former, but with the latter
  66you will.
  67
  68 * Just as the filesystem '.' (period) refers to the current directory,
  69   using a '.' as a repository name in Git (a dot-repository) is a relative
  70   path and means your current repository.
  71
  72Here are the rules regarding the "flags" that you should follow when you are
  73scripting Git:
  74
  75 * it's preferred to use the non-dashed form of Git commands, which means that
  76   you should prefer `git foo` to `git-foo`.
  77
  78 * splitting short options to separate words (prefer `git foo -a -b`
  79   to `git foo -ab`, the latter may not even work).
  80
  81 * when a command-line option takes an argument, use the 'stuck' form.  In
  82   other words, write `git foo -oArg` instead of `git foo -o Arg` for short
  83   options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
  84   for long options.  An option that takes optional option-argument must be
  85   written in the 'stuck' form.
  86
  87 * when you give a revision parameter to a command, make sure the parameter is
  88   not ambiguous with a name of a file in the work tree.  E.g. do not write
  89   `git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
  90   if you happen to have a file called `HEAD` in the work tree.
  91
  92 * many commands allow a long option `--option` to be abbreviated
  93   only to their unique prefix (e.g. if there is no other option
  94   whose name begins with `opt`, you may be able to spell `--opt` to
  95   invoke the `--option` flag), but you should fully spell them out
  96   when writing your scripts; later versions of Git may introduce a
  97   new option whose name shares the same prefix, e.g. `--optimize`,
  98   to make a short prefix that used to be unique no longer unique.
  99
 100
 101ENHANCED OPTION PARSER
 102----------------------
 103From the Git 1.5.4 series and further, many Git commands (not all of them at the
 104time of the writing though) come with an enhanced option parser.
 105
 106Here is a list of the facilities provided by this option parser.
 107
 108
 109Magic Options
 110~~~~~~~~~~~~~
 111Commands which have the enhanced option parser activated all understand a
 112couple of magic command-line options:
 113
 114-h::
 115        gives a pretty printed usage of the command.
 116+
 117---------------------------------------------
 118$ git describe -h
 119usage: git describe [<options>] <commit-ish>*
 120   or: git describe [<options>] --dirty
 121
 122    --contains            find the tag that comes after the commit
 123    --debug               debug search strategy on stderr
 124    --all                 use any ref
 125    --tags                use any tag, even unannotated
 126    --long                always use long format
 127    --abbrev[=<n>]        use <n> digits to display SHA-1s
 128---------------------------------------------
 129
 130--help-all::
 131        Some Git commands take options that are only used for plumbing or that
 132        are deprecated, and such options are hidden from the default usage. This
 133        option gives the full list of options.
 134
 135
 136Negating options
 137~~~~~~~~~~~~~~~~
 138Options with long option names can be negated by prefixing `--no-`. For
 139example, `git branch` has the option `--track` which is 'on' by default. You
 140can use `--no-track` to override that behaviour. The same goes for `--color`
 141and `--no-color`.
 142
 143
 144Aggregating short options
 145~~~~~~~~~~~~~~~~~~~~~~~~~
 146Commands that support the enhanced option parser allow you to aggregate short
 147options. This means that you can for example use `git rm -rf` or
 148`git clean -fdx`.
 149
 150
 151Abbreviating long options
 152~~~~~~~~~~~~~~~~~~~~~~~~~
 153Commands that support the enhanced option parser accepts unique
 154prefix of a long option as if it is fully spelled out, but use this
 155with a caution.  For example, `git commit --amen` behaves as if you
 156typed `git commit --amend`, but that is true only until a later version
 157of Git introduces another option that shares the same prefix,
 158e.g. `git commit --amenity` option.
 159
 160
 161Separating argument from the option
 162~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 163You can write the mandatory option parameter to an option as a separate
 164word on the command line.  That means that all the following uses work:
 165
 166----------------------------
 167$ git foo --long-opt=Arg
 168$ git foo --long-opt Arg
 169$ git foo -oArg
 170$ git foo -o Arg
 171----------------------------
 172
 173However, this is *NOT* allowed for switches with an optional value, where the
 174'stuck' form must be used:
 175----------------------------
 176$ git describe --abbrev HEAD     # correct
 177$ git describe --abbrev=10 HEAD  # correct
 178$ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
 179----------------------------
 180
 181
 182NOTES ON FREQUENTLY CONFUSED OPTIONS
 183------------------------------------
 184
 185Many commands that can work on files in the working tree
 186and/or in the index can take `--cached` and/or `--index`
 187options.  Sometimes people incorrectly think that, because
 188the index was originally called cache, these two are
 189synonyms.  They are *not* -- these two options mean very
 190different things.
 191
 192 * The `--cached` option is used to ask a command that
 193   usually works on files in the working tree to *only* work
 194   with the index.  For example, `git grep`, when used
 195   without a commit to specify from which commit to look for
 196   strings in, usually works on files in the working tree,
 197   but with the `--cached` option, it looks for strings in
 198   the index.
 199
 200 * The `--index` option is used to ask a command that
 201   usually works on files in the working tree to *also*
 202   affect the index.  For example, `git stash apply` usually
 203   merges changes recorded in a stash entry to the working tree,
 204   but with the `--index` option, it also merges changes to
 205   the index as well.
 206
 207`git apply` command can be used with `--cached` and
 208`--index` (but not at the same time).  Usually the command
 209only affects the files in the working tree, but with
 210`--index`, it patches both the files and their index
 211entries, and with `--cached`, it modifies only the index
 212entries.
 213
 214See also http://marc.info/?l=git&m=116563135620359 and
 215http://marc.info/?l=git&m=119150393620273 for further
 216information.
 217
 218Some other commands that also work on files in the working tree and/or
 219in the index can take `--staged` and/or `--worktree`.
 220
 221* `--staged` is exactly like `--cached`, which is used to ask a
 222  command to only work on the index, not the working tree.
 223
 224* `--worktree` is the opposite, to ask a command to work on the
 225  working tree only, not the index.
 226
 227* The two options can be specified together to ask a command to work
 228  on both the index and the working tree.
 229
 230GIT
 231---
 232Part of the linkgit:git[1] suite