view mercurial/hook.py @ 11989:f853873fc66d

aliases: provide more flexible ways to work with shell alias arguments

This patch changes the functionality of shell aliases to add more powerful
options for working with shell alias arguments.

First: the alias name + arguments to a shell alias are set as an HG_ARGS
environment variable, delimited by spaces. This matches the behavior of hooks.

Second: any occurrences of "$@" (without quotes) are replaced with the
arguments, separated by spaces. This happens *before* the alias gets to the shell.

Third: any positive numeric variables ("$1", "$2", etc) are replaced with the
appropriate argument, indexed from 1. "$0" is replaced with the name of the
alias. Any "extra" numeric variables are replaced with an empty string.  This
happens *before* the alias gets to the shell.

These changes allow for more flexible shell aliases:

    [alias]
    echo = !echo $@
    count = !hg log -r "$@" --template='.' | wc -c | sed -e 's/ //g'
    qqueuemv = !mv "`hg root`/.hg/patches-$1" "`hg root`/.hg/patches-$2"

In action:

    $ hg echo foo
    foo

    $ hg count 'branch(default)'
    901

    $ hg count 'branch(stable) and keyword(fixes)'
    102

    $ hg qqueuemv myfeature somefeature

# hook.py - hook support for mercurial
#
# Copyright 2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import os, sys
import extensions, util

def _pythonhook(ui, repo, name, hname, funcname, args, throw):
    '''call python hook. hook is callable object, looked up as
    name in python module. if callable returns "true", hook
    fails, else passes. if hook raises exception, treated as
    hook failure. exception propagates if throw is "true".

    reason for "true" meaning "hook failed" is so that
    unmodified commands (e.g. mercurial.commands.update) can
    be run as hooks without wrappers to convert return values.'''

    ui.note(_("calling hook %s: %s\n") % (hname, funcname))
    obj = funcname
    if not hasattr(obj, '__call__'):
        d = funcname.rfind('.')
        if d == -1:
            raise util.Abort(_('%s hook is invalid ("%s" not in '
                               'a module)') % (hname, funcname))
        modname = funcname[:d]
        oldpaths = sys.path
        if hasattr(sys, "frozen"):
            # binary installs require sys.path manipulation
            modpath, modfile = os.path.split(modname)
            if modpath and modfile:
                sys.path = sys.path[:] + [modpath]
                modname = modfile
        try:
            obj = __import__(modname)
        except ImportError:
            e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
            try:
                # extensions are loaded with hgext_ prefix
                obj = __import__("hgext_%s" % modname)
            except ImportError:
                e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
                if ui.tracebackflag:
                    ui.warn(_('exception from first failed import attempt:\n'))
                ui.traceback(e1)
                if ui.tracebackflag:
                    ui.warn(_('exception from second failed import attempt:\n'))
                ui.traceback(e2)
                raise util.Abort(_('%s hook is invalid '
                                   '(import of "%s" failed)') %
                                 (hname, modname))
        sys.path = oldpaths
        try:
            for p in funcname.split('.')[1:]:
                obj = getattr(obj, p)
        except AttributeError:
            raise util.Abort(_('%s hook is invalid '
                               '("%s" is not defined)') %
                             (hname, funcname))
        if not hasattr(obj, '__call__'):
            raise util.Abort(_('%s hook is invalid '
                               '("%s" is not callable)') %
                             (hname, funcname))
    try:
        r = obj(ui=ui, repo=repo, hooktype=name, **args)
    except KeyboardInterrupt:
        raise
    except Exception, exc:
        if isinstance(exc, util.Abort):
            ui.warn(_('error: %s hook failed: %s\n') %
                         (hname, exc.args[0]))
        else:
            ui.warn(_('error: %s hook raised an exception: '
                           '%s\n') % (hname, exc))
        if throw:
            raise
        ui.traceback()
        return True
    if r:
        if throw:
            raise util.Abort(_('%s hook failed') % hname)
        ui.warn(_('warning: %s hook failed\n') % hname)
    return r

def _exthook(ui, repo, name, cmd, args, throw):
    ui.note(_("running hook %s: %s\n") % (name, cmd))

    env = {}
    for k, v in args.iteritems():
        if hasattr(v, '__call__'):
            v = v()
        env['HG_' + k.upper()] = v

    if repo:
        cwd = repo.root
    else:
        cwd = os.getcwd()
    if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):
        r = util.system(cmd, environ=env, cwd=cwd, out=ui)
    else:
        r = util.system(cmd, environ=env, cwd=cwd)
    if r:
        desc, r = util.explain_exit(r)
        if throw:
            raise util.Abort(_('%s hook %s') % (name, desc))
        ui.warn(_('warning: %s hook %s\n') % (name, desc))
    return r

_redirect = False
def redirect(state):
    global _redirect
    _redirect = state

def hook(ui, repo, name, throw=False, **args):
    r = False

    oldstdout = -1
    if _redirect:
        stdoutno = sys.__stdout__.fileno()
        stderrno = sys.__stderr__.fileno()
        # temporarily redirect stdout to stderr, if possible
        if stdoutno >= 0 and stderrno >= 0:
            oldstdout = os.dup(stdoutno)
            os.dup2(stderrno, stdoutno)

    try:
        for hname, cmd in ui.configitems('hooks'):
            if hname.split('.')[0] != name or not cmd:
                continue
            if hasattr(cmd, '__call__'):
                r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
            elif cmd.startswith('python:'):
                if cmd.count(':') >= 2:
                    path, cmd = cmd[7:].rsplit(':', 1)
                    mod = extensions.loadpath(path, 'hghook.%s' % hname)
                    hookfn = getattr(mod, cmd)
                else:
                    hookfn = cmd[7:].strip()
                r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
            else:
                r = _exthook(ui, repo, hname, cmd, args, throw) or r
    finally:
        if _redirect and oldstdout >= 0:
            os.dup2(oldstdout, stdoutno)
            os.close(oldstdout)

    return r