Documentation / gitcredentials.txton commit fetch: don't redundantly NULL something calloc() gave us (aa59e0e)
   1gitcredentials(7)
   2=================
   3
   4NAME
   5----
   6gitcredentials - providing usernames and passwords to Git
   7
   8SYNOPSIS
   9--------
  10------------------
  11git config credential.https://example.com.username myusername
  12git config credential.helper "$helper $options"
  13------------------
  14
  15DESCRIPTION
  16-----------
  17
  18Git will sometimes need credentials from the user in order to perform
  19operations; for example, it may need to ask for a username and password
  20in order to access a remote repository over HTTP. This manual describes
  21the mechanisms Git uses to request these credentials, as well as some
  22features to avoid inputting these credentials repeatedly.
  23
  24REQUESTING CREDENTIALS
  25----------------------
  26
  27Without any credential helpers defined, Git will try the following
  28strategies to ask the user for usernames and passwords:
  29
  301. If the `GIT_ASKPASS` environment variable is set, the program
  31   specified by the variable is invoked. A suitable prompt is provided
  32   to the program on the command line, and the user's input is read
  33   from its standard output.
  34
  352. Otherwise, if the `core.askPass` configuration variable is set, its
  36   value is used as above.
  37
  383. Otherwise, if the `SSH_ASKPASS` environment variable is set, its
  39   value is used as above.
  40
  414. Otherwise, the user is prompted on the terminal.
  42
  43AVOIDING REPETITION
  44-------------------
  45
  46It can be cumbersome to input the same credentials over and over.  Git
  47provides two methods to reduce this annoyance:
  48
  491. Static configuration of usernames for a given authentication context.
  50
  512. Credential helpers to cache or store passwords, or to interact with
  52   a system password wallet or keychain.
  53
  54The first is simple and appropriate if you do not have secure storage available
  55for a password. It is generally configured by adding this to your config:
  56
  57---------------------------------------
  58[credential "https://example.com"]
  59        username = me
  60---------------------------------------
  61
  62Credential helpers, on the other hand, are external programs from which Git can
  63request both usernames and passwords; they typically interface with secure
  64storage provided by the OS or other programs.
  65
  66To use a helper, you must first select one to use. Git currently
  67includes the following helpers:
  68
  69cache::
  70
  71        Cache credentials in memory for a short period of time. See
  72        linkgit:git-credential-cache[1] for details.
  73
  74store::
  75
  76        Store credentials indefinitely on disk. See
  77        linkgit:git-credential-store[1] for details.
  78
  79You may also have third-party helpers installed; search for
  80`credential-*` in the output of `git help -a`, and consult the
  81documentation of individual helpers.  Once you have selected a helper,
  82you can tell Git to use it by putting its name into the
  83credential.helper variable.
  84
  851. Find a helper.
  86+
  87-------------------------------------------
  88$ git help -a | grep credential-
  89credential-foo
  90-------------------------------------------
  91
  922. Read its description.
  93+
  94-------------------------------------------
  95$ git help credential-foo
  96-------------------------------------------
  97
  983. Tell Git to use it.
  99+
 100-------------------------------------------
 101$ git config --global credential.helper foo
 102-------------------------------------------
 103
 104
 105CREDENTIAL CONTEXTS
 106-------------------
 107
 108Git considers each credential to have a context defined by a URL. This context
 109is used to look up context-specific configuration, and is passed to any
 110helpers, which may use it as an index into secure storage.
 111
 112For instance, imagine we are accessing `https://example.com/foo.git`. When Git
 113looks into a config file to see if a section matches this context, it will
 114consider the two a match if the context is a more-specific subset of the
 115pattern in the config file. For example, if you have this in your config file:
 116
 117--------------------------------------
 118[credential "https://example.com"]
 119        username = foo
 120--------------------------------------
 121
 122then we will match: both protocols are the same, both hosts are the same, and
 123the "pattern" URL does not care about the path component at all. However, this
 124context would not match:
 125
 126--------------------------------------
 127[credential "https://kernel.org"]
 128        username = foo
 129--------------------------------------
 130
 131because the hostnames differ. Nor would it match `foo.example.com`; Git
 132compares hostnames exactly, without considering whether two hosts are part of
 133the same domain. Likewise, a config entry for `http://example.com` would not
 134match: Git compares the protocols exactly.
 135
 136
 137CONFIGURATION OPTIONS
 138---------------------
 139
 140Options for a credential context can be configured either in
 141`credential.*` (which applies to all credentials), or
 142`credential.<url>.*`, where <url> matches the context as described
 143above.
 144
 145The following options are available in either location:
 146
 147helper::
 148
 149        The name of an external credential helper, and any associated options.
 150        If the helper name is not an absolute path, then the string `git
 151        credential-` is prepended. The resulting string is executed by the
 152        shell (so, for example, setting this to `foo --option=bar` will execute
 153        `git credential-foo --option=bar` via the shell. See the manual of
 154        specific helpers for examples of their use.
 155+
 156If there are multiple instances of the `credential.helper` configuration
 157variable, each helper will be tried in turn, and may provide a username,
 158password, or nothing. Once Git has acquired both a username and a
 159password, no more helpers will be tried.
 160+
 161If `credential.helper` is configured to the empty string, this resets
 162the helper list to empty (so you may override a helper set by a
 163lower-priority config file by configuring the empty-string helper,
 164followed by whatever set of helpers you would like).
 165
 166username::
 167
 168        A default username, if one is not provided in the URL.
 169
 170useHttpPath::
 171
 172        By default, Git does not consider the "path" component of an http URL
 173        to be worth matching via external helpers. This means that a credential
 174        stored for `https://example.com/foo.git` will also be used for
 175        `https://example.com/bar.git`. If you do want to distinguish these
 176        cases, set this option to `true`.
 177
 178
 179CUSTOM HELPERS
 180--------------
 181
 182You can write your own custom helpers to interface with any system in
 183which you keep credentials. See the documentation for Git's
 184link:technical/api-credentials.html[credentials API] for details.
 185
 186GIT
 187---
 188Part of the linkgit:git[1] suite