view mercurial/helptext/pager.txt @ 48951:cf99c4af1079

chgserver: remove Python 2 file descriptor logic

Follows up 0bb28b7736bc "chgserver: remove Python 2 support code."

On Python 2, we had to close newfp prior to restoring the original file
description since "delete newfp" would otherwise close the file descriptor
shared with the long-lived fp:

  in attachio():
    newfp = os.fdopen(fp.fileno(), mode, bufsize)
  in _restoreio():
    newfp.close()  # temporarily close newfp.fileno() (= fp.fileno())
    os.dup2(fd, fp.fileno())  # reopen fp.fileno() with original fd

On the other hand, we shouldn't call newfp.close() on Python 3 since
any function calls are proxied to the underlying file object by
procutil.LineBufferedWrapper.

Some Mercurial commands can produce a lot of output, and Mercurial will
attempt to use a pager to make those commands more pleasant.

To set the pager that should be used, set the application variable::

  [pager]
  pager = less -FRX

If no pager is set in the user or repository configuration, Mercurial uses the
environment variable $PAGER. If $PAGER is not set, pager.pager from the default
or system configuration is used. If none of these are set, a default pager will
be used, typically `less` on Unix and `more` on Windows.

.. container:: windows

  On Windows, `more` is not color aware, so using it effectively disables color.
  MSYS and Cygwin shells provide `less` as a pager, which can be configured to
  support ANSI color codes.  See :hg:`help config.color.pagermode` to configure
  the color mode when invoking a pager.

You can disable the pager for certain commands by adding them to the
pager.ignore list::

  [pager]
  ignore = version, help, update

To ignore global commands like :hg:`version` or :hg:`help`, you have
to specify them in your user configuration file.

To control whether the pager is used at all for an individual command,
you can use --pager=<value>:

  - use as needed: `auto`.
  - require the pager: `yes` or `on`.
  - suppress the pager: `no` or `off` (any unrecognized value
    will also work).

To globally turn off all attempts to use a pager, set::

  [ui]
  paginate = never

which will prevent the pager from running.