Documentation / gitcli.txton commit MALLOC_CHECK: various clean-ups (1b3185f)
   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
  45 * Many commands allow wildcards in paths, but you need to protect
  46   them from getting globbed by the shell.  These two mean different
  47   things:
  48+
  49--------------------------------
  50$ git checkout -- *.c
  51$ git checkout -- \*.c
  52--------------------------------
  53+
  54The former lets your shell expand the fileglob, and you are asking
  55the dot-C files in your working tree to be overwritten with the version
  56in the index.  The latter passes the `*.c` to Git, and you are asking
  57the paths in the index that match the pattern to be checked out to your
  58working tree.  After running `git add hello.c; rm hello.c`, you will _not_
  59see `hello.c` in your working tree with the former, but with the latter
  60you will.
  61
  62Here are the rules regarding the "flags" that you should follow when you are
  63scripting git:
  64
  65 * it's preferred to use the non dashed form of git commands, which means that
  66   you should prefer `git foo` to `git-foo`.
  67
  68 * splitting short options to separate words (prefer `git foo -a -b`
  69   to `git foo -ab`, the latter may not even work).
  70
  71 * when a command line option takes an argument, use the 'sticked' form.  In
  72   other words, write `git foo -oArg` instead of `git foo -o Arg` for short
  73   options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
  74   for long options.  An option that takes optional option-argument must be
  75   written in the 'sticked' form.
  76
  77 * when you give a revision parameter to a command, make sure the parameter is
  78   not ambiguous with a name of a file in the work tree.  E.g. do not write
  79   `git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
  80   if you happen to have a file called `HEAD` in the work tree.
  81
  82 * many commands allow a long option "--option" to be abbreviated
  83   only to their unique prefix (e.g. if there is no other option
  84   whose name begins with "opt", you may be able to spell "--opt" to
  85   invoke the "--option" flag), but you should fully spell them out
  86   when writing your scripts; later versions of Git may introduce a
  87   new option whose name shares the same prefix, e.g. "--optimize",
  88   to make a short prefix that used to be unique no longer unique.
  89
  90
  91ENHANCED OPTION PARSER
  92----------------------
  93From the git 1.5.4 series and further, many git commands (not all of them at the
  94time of the writing though) come with an enhanced option parser.
  95
  96Here is an exhaustive list of the facilities provided by this option parser.
  97
  98
  99Magic Options
 100~~~~~~~~~~~~~
 101Commands which have the enhanced option parser activated all understand a
 102couple of magic command line options:
 103
 104-h::
 105        gives a pretty printed usage of the command.
 106+
 107---------------------------------------------
 108$ git describe -h
 109usage: git describe [options] <committish>*
 110
 111    --contains            find the tag that comes after the commit
 112    --debug               debug search strategy on stderr
 113    --all                 use any ref in .git/refs
 114    --tags                use any tag in .git/refs/tags
 115    --abbrev [<n>]        use <n> digits to display SHA-1s
 116    --candidates <n>      consider <n> most recent tags (default: 10)
 117---------------------------------------------
 118
 119--help-all::
 120        Some git commands take options that are only used for plumbing or that
 121        are deprecated, and such options are hidden from the default usage. This
 122        option gives the full list of options.
 123
 124
 125Negating options
 126~~~~~~~~~~~~~~~~
 127Options with long option names can be negated by prefixing `--no-`. For
 128example, `git branch` has the option `--track` which is 'on' by default. You
 129can use `--no-track` to override that behaviour. The same goes for `--color`
 130and `--no-color`.
 131
 132
 133Aggregating short options
 134~~~~~~~~~~~~~~~~~~~~~~~~~
 135Commands that support the enhanced option parser allow you to aggregate short
 136options. This means that you can for example use `git rm -rf` or
 137`git clean -fdx`.
 138
 139
 140Separating argument from the option
 141~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 142You can write the mandatory option parameter to an option as a separate
 143word on the command line.  That means that all the following uses work:
 144
 145----------------------------
 146$ git foo --long-opt=Arg
 147$ git foo --long-opt Arg
 148$ git foo -oArg
 149$ git foo -o Arg
 150----------------------------
 151
 152However, this is *NOT* allowed for switches with an optional value, where the
 153'sticked' form must be used:
 154----------------------------
 155$ git describe --abbrev HEAD     # correct
 156$ git describe --abbrev=10 HEAD  # correct
 157$ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
 158----------------------------
 159
 160
 161NOTES ON FREQUENTLY CONFUSED OPTIONS
 162------------------------------------
 163
 164Many commands that can work on files in the working tree
 165and/or in the index can take `--cached` and/or `--index`
 166options.  Sometimes people incorrectly think that, because
 167the index was originally called cache, these two are
 168synonyms.  They are *not* -- these two options mean very
 169different things.
 170
 171 * The `--cached` option is used to ask a command that
 172   usually works on files in the working tree to *only* work
 173   with the index.  For example, `git grep`, when used
 174   without a commit to specify from which commit to look for
 175   strings in, usually works on files in the working tree,
 176   but with the `--cached` option, it looks for strings in
 177   the index.
 178
 179 * The `--index` option is used to ask a command that
 180   usually works on files in the working tree to *also*
 181   affect the index.  For example, `git stash apply` usually
 182   merges changes recorded in a stash to the working tree,
 183   but with the `--index` option, it also merges changes to
 184   the index as well.
 185
 186`git apply` command can be used with `--cached` and
 187`--index` (but not at the same time).  Usually the command
 188only affects the files in the working tree, but with
 189`--index`, it patches both the files and their index
 190entries, and with `--cached`, it modifies only the index
 191entries.
 192
 193See also http://marc.info/?l=git&m=116563135620359 and
 194http://marc.info/?l=git&m=119150393620273 for further
 195information.
 196
 197GIT
 198---
 199Part of the linkgit:git[1] suite