Source code for pypsi.commands.xargs

#
# Copyright (c) 2015, Adam Meily <meily.adam@gmail.com>
# Pypsi - https://github.com/ameily/pypsi
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#

from pypsi.core import Command, PypsiArgParser, CommandShortCircuit
import sys
import argparse

XArgsUsage = """{name} [-h] [-I REPSTR] COMMAND"""


class XArgsCommand(Command):
    '''
    Execute a command for each line of input from :data:`sys.stdin`.
    '''

    def __init__(self, name='xargs', topic='shell',
                 brief='build and execute command lines from stdin', **kwargs):
        self.parser = PypsiArgParser(
            prog=name,
            description=brief,
            usage=XArgsUsage.format(name=name)
        )

        self.parser.add_argument(
            '-I', default='{}', action='store',
            metavar='REPSTR', help='string token to replace',
            dest='token'
        )

        self.parser.add_argument(
            'command', nargs=argparse.REMAINDER, help="command to execute",
            metavar='COMMAND'
        )

        super(XArgsCommand, self).__init__(
            name=name, topic=topic, usage=self.parser.format_help(),
            brief=brief, **kwargs
        )

    def run(self, shell, args):
        try:
            ns = self.parser.parse_args(args)
        except CommandShortCircuit as e:
            return e.code

        if not ns.command:
            self.error(shell, "missing command")
            return 1

        base = ' '.join([
            '"{}"'.format(c.replace('"', '\\"')) for c in ns.command
        ])

        for line in sys.stdin:
            cmd = base.replace(ns.token, line.strip())
            shell.execute(cmd)

        return 0