view mercurial/help/flags.txt @ 39814:d059cb669632

wireprotov2: allow multiple fields to follow revision maps

The *data wire protocol commands emit a series of CBOR values.
Because revision/delta data may be large, their data is emitted
outside the map as a top-level bytestring value.

Before this commit, we'd emit a single optional bytestring
value after the revision descriptor map. This got the job done.
But it was limiting in that we could only send a single field.
And, it required the consumer to know that the presence of a
key in the map implied the existence of a following bytestring
value.

This commit changes the encoding strategy so top-level bytestring
values in the stream are explicitly denoted in a "fieldsfollowing"
key. This key contains an array defining what fields that follow
and the expected size of each field.

By defining things this way, we can easily send N bytestring
values without any ambiguity about their order. In addition,
clients only need to know how to parse ``fieldsfollowing`` to
know if extra values are present.

Because this breaks backwards compatibility, we've bumped the version
number of the wire protocol version 2 API endpoint.

Differential Revision: https://phab.mercurial-scm.org/D4620

Most Mercurial commands accept various flags.

Flag names
==========

Flags for each command are listed in :hg:`help` for that command.
Additionally, some flags, such as --repository, are global and can be used with
any command - those are seen in :hg:`help -v`, and can be specified before or
after the command.

Every flag has at least a long name, such as --repository. Some flags may also
have a short one-letter name, such as the equivalent -R. Using the short or long
name is equivalent and has the same effect.

Flags that have a short name can also be bundled together - for instance, to
specify both --edit (short -e) and --interactive (short -i), one could use::

    hg commit -ei

If any of the bundled flags takes a value (i.e. is not a boolean), it must be
last, followed by the value::

    hg commit -im 'Message'

Flag types
==========

Mercurial command-line flags can be strings, numbers, booleans, or lists of
strings.

Specifying flag values
======================

The following syntaxes are allowed, assuming a flag 'flagname' with short name
'f'::

    --flagname=foo
    --flagname foo
    -f foo
    -ffoo

This syntax applies to all non-boolean flags (strings, numbers or lists).

Specifying boolean flags
========================

Boolean flags do not take a value parameter. To specify a boolean, use the flag
name to set it to true, or the same name prefixed with 'no-' to set it to
false::

    hg commit --interactive
    hg commit --no-interactive

Specifying list flags
=====================

List flags take multiple values. To specify them, pass the flag multiple times::

    hg files --include mercurial --include tests

Setting flag defaults
=====================

In order to set a default value for a flag in an hgrc file, it is recommended to
use aliases::

    [alias]
    commit = commit --interactive

For more information on hgrc files, see :hg:`help config`.

Overriding flags on the command line
====================================

If the same non-list flag is specified multiple times on the command line, the
latest specification is used::

    hg commit -m "Ignored value" -m "Used value"

This includes the use of aliases - e.g., if one has::

    [alias]
    committemp = commit -m "Ignored value"

then the following command will override that -m::

    hg committemp -m "Used value"

Overriding flag defaults
========================

Every flag has a default value, and you may also set your own defaults in hgrc
as described above.
Except for list flags, defaults can be overridden on the command line simply by
specifying the flag in that location.

Hidden flags
============

Some flags are not shown in a command's help by default - specifically, those
that are deemed to be experimental, deprecated or advanced. To show all flags,
add the --verbose flag for the help command::

    hg help --verbose commit