Documentation / gitcli.txton commit vcs-svn: remove buffer_read_string (7e2fe3a)
   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
  41When writing a script that is expected to handle random user-input, it is
  42a good practice to make it explicit which arguments are which by placing
  43disambiguating `\--` at appropriate places.
  44
  45Here are the rules regarding the "flags" that you should follow when you are
  46scripting git:
  47
  48 * it's preferred to use the non dashed form of git commands, which means that
  49   you should prefer `git foo` to `git-foo`.
  50
  51 * splitting short options to separate words (prefer `git foo -a -b`
  52   to `git foo -ab`, the latter may not even work).
  53
  54 * when a command line option takes an argument, use the 'sticked' form.  In
  55   other words, write `git foo -oArg` instead of `git foo -o Arg` for short
  56   options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
  57   for long options.  An option that takes optional option-argument must be
  58   written in the 'sticked' form.
  59
  60 * when you give a revision parameter to a command, make sure the parameter is
  61   not ambiguous with a name of a file in the work tree.  E.g. do not write
  62   `git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
  63   if you happen to have a file called `HEAD` in the work tree.
  64
  65
  66ENHANCED OPTION PARSER
  67----------------------
  68From the git 1.5.4 series and further, many git commands (not all of them at the
  69time of the writing though) come with an enhanced option parser.
  70
  71Here is an exhaustive list of the facilities provided by this option parser.
  72
  73
  74Magic Options
  75~~~~~~~~~~~~~
  76Commands which have the enhanced option parser activated all understand a
  77couple of magic command line options:
  78
  79-h::
  80        gives a pretty printed usage of the command.
  81+
  82---------------------------------------------
  83$ git describe -h
  84usage: git describe [options] <committish>*
  85
  86    --contains            find the tag that comes after the commit
  87    --debug               debug search strategy on stderr
  88    --all                 use any ref in .git/refs
  89    --tags                use any tag in .git/refs/tags
  90    --abbrev [<n>]        use <n> digits to display SHA-1s
  91    --candidates <n>      consider <n> most recent tags (default: 10)
  92---------------------------------------------
  93
  94--help-all::
  95        Some git commands take options that are only used for plumbing or that
  96        are deprecated, and such options are hidden from the default usage. This
  97        option gives the full list of options.
  98
  99
 100Negating options
 101~~~~~~~~~~~~~~~~
 102Options with long option names can be negated by prefixing `--no-`. For
 103example, `git branch` has the option `--track` which is 'on' by default. You
 104can use `--no-track` to override that behaviour. The same goes for `--color`
 105and `--no-color`.
 106
 107
 108Aggregating short options
 109~~~~~~~~~~~~~~~~~~~~~~~~~
 110Commands that support the enhanced option parser allow you to aggregate short
 111options. This means that you can for example use `git rm -rf` or
 112`git clean -fdx`.
 113
 114
 115Separating argument from the option
 116~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 117You can write the mandatory option parameter to an option as a separate
 118word on the command line.  That means that all the following uses work:
 119
 120----------------------------
 121$ git foo --long-opt=Arg
 122$ git foo --long-opt Arg
 123$ git foo -oArg
 124$ git foo -o Arg
 125----------------------------
 126
 127However, this is *NOT* allowed for switches with an optional value, where the
 128'sticked' form must be used:
 129----------------------------
 130$ git describe --abbrev HEAD     # correct
 131$ git describe --abbrev=10 HEAD  # correct
 132$ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
 133----------------------------
 134
 135
 136NOTES ON FREQUENTLY CONFUSED OPTIONS
 137------------------------------------
 138
 139Many commands that can work on files in the working tree
 140and/or in the index can take `--cached` and/or `--index`
 141options.  Sometimes people incorrectly think that, because
 142the index was originally called cache, these two are
 143synonyms.  They are *not* -- these two options mean very
 144different things.
 145
 146 * The `--cached` option is used to ask a command that
 147   usually works on files in the working tree to *only* work
 148   with the index.  For example, `git grep`, when used
 149   without a commit to specify from which commit to look for
 150   strings in, usually works on files in the working tree,
 151   but with the `--cached` option, it looks for strings in
 152   the index.
 153
 154 * The `--index` option is used to ask a command that
 155   usually works on files in the working tree to *also*
 156   affect the index.  For example, `git stash apply` usually
 157   merges changes recorded in a stash to the working tree,
 158   but with the `--index` option, it also merges changes to
 159   the index as well.
 160
 161`git apply` command can be used with `--cached` and
 162`--index` (but not at the same time).  Usually the command
 163only affects the files in the working tree, but with
 164`--index`, it patches both the files and their index
 165entries, and with `--cached`, it modifies only the index
 166entries.
 167
 168See also http://marc.info/?l=git&m=116563135620359 and
 169http://marc.info/?l=git&m=119150393620273 for further
 170information.
 171
 172Documentation
 173-------------
 174Documentation by Pierre Habouzit and the git-list <git@vger.kernel.org>.
 175
 176GIT
 177---
 178Part of the linkgit:git[1] suite