Documentation / gitcli.txton commit fetch-pack: eliminate spurious error messages (5f0fc64)
   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 * many commands allow a long option "--option" to be abbreviated
  66   only to their unique prefix (e.g. if there is no other option
  67   whose name begins with "opt", you may be able to spell "--opt" to
  68   invoke the "--option" flag), but you should fully spell them out
  69   when writing your scripts; later versions of Git may introduce a
  70   new option whose name shares the same prefix, e.g. "--optimize",
  71   to make a short prefix that used to be unique no longer unique.
  72
  73
  74ENHANCED OPTION PARSER
  75----------------------
  76From the git 1.5.4 series and further, many git commands (not all of them at the
  77time of the writing though) come with an enhanced option parser.
  78
  79Here is an exhaustive list of the facilities provided by this option parser.
  80
  81
  82Magic Options
  83~~~~~~~~~~~~~
  84Commands which have the enhanced option parser activated all understand a
  85couple of magic command line options:
  86
  87-h::
  88        gives a pretty printed usage of the command.
  89+
  90---------------------------------------------
  91$ git describe -h
  92usage: git describe [options] <committish>*
  93
  94    --contains            find the tag that comes after the commit
  95    --debug               debug search strategy on stderr
  96    --all                 use any ref in .git/refs
  97    --tags                use any tag in .git/refs/tags
  98    --abbrev [<n>]        use <n> digits to display SHA-1s
  99    --candidates <n>      consider <n> most recent tags (default: 10)
 100---------------------------------------------
 101
 102--help-all::
 103        Some git commands take options that are only used for plumbing or that
 104        are deprecated, and such options are hidden from the default usage. This
 105        option gives the full list of options.
 106
 107
 108Negating options
 109~~~~~~~~~~~~~~~~
 110Options with long option names can be negated by prefixing `--no-`. For
 111example, `git branch` has the option `--track` which is 'on' by default. You
 112can use `--no-track` to override that behaviour. The same goes for `--color`
 113and `--no-color`.
 114
 115
 116Aggregating short options
 117~~~~~~~~~~~~~~~~~~~~~~~~~
 118Commands that support the enhanced option parser allow you to aggregate short
 119options. This means that you can for example use `git rm -rf` or
 120`git clean -fdx`.
 121
 122
 123Separating argument from the option
 124~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 125You can write the mandatory option parameter to an option as a separate
 126word on the command line.  That means that all the following uses work:
 127
 128----------------------------
 129$ git foo --long-opt=Arg
 130$ git foo --long-opt Arg
 131$ git foo -oArg
 132$ git foo -o Arg
 133----------------------------
 134
 135However, this is *NOT* allowed for switches with an optional value, where the
 136'sticked' form must be used:
 137----------------------------
 138$ git describe --abbrev HEAD     # correct
 139$ git describe --abbrev=10 HEAD  # correct
 140$ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
 141----------------------------
 142
 143
 144NOTES ON FREQUENTLY CONFUSED OPTIONS
 145------------------------------------
 146
 147Many commands that can work on files in the working tree
 148and/or in the index can take `--cached` and/or `--index`
 149options.  Sometimes people incorrectly think that, because
 150the index was originally called cache, these two are
 151synonyms.  They are *not* -- these two options mean very
 152different things.
 153
 154 * The `--cached` option is used to ask a command that
 155   usually works on files in the working tree to *only* work
 156   with the index.  For example, `git grep`, when used
 157   without a commit to specify from which commit to look for
 158   strings in, usually works on files in the working tree,
 159   but with the `--cached` option, it looks for strings in
 160   the index.
 161
 162 * The `--index` option is used to ask a command that
 163   usually works on files in the working tree to *also*
 164   affect the index.  For example, `git stash apply` usually
 165   merges changes recorded in a stash to the working tree,
 166   but with the `--index` option, it also merges changes to
 167   the index as well.
 168
 169`git apply` command can be used with `--cached` and
 170`--index` (but not at the same time).  Usually the command
 171only affects the files in the working tree, but with
 172`--index`, it patches both the files and their index
 173entries, and with `--cached`, it modifies only the index
 174entries.
 175
 176See also http://marc.info/?l=git&m=116563135620359 and
 177http://marc.info/?l=git&m=119150393620273 for further
 178information.
 179
 180GIT
 181---
 182Part of the linkgit:git[1] suite