qemu/include/io/channel-command.h
Daniel P. Berrange 821791b505 io: fix description of @errp parameter initialization
The "Error **errp" parameters must be NULL initialized
not uninitialized.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-01-20 11:31:01 +00:00

92 lines
2.8 KiB
C

/*
* QEMU I/O channels external command driver
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef QIO_CHANNEL_COMMAND_H__
#define QIO_CHANNEL_COMMAND_H__
#include "io/channel.h"
#define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
#define QIO_CHANNEL_COMMAND(obj) \
OBJECT_CHECK(QIOChannelCommand, (obj), TYPE_QIO_CHANNEL_COMMAND)
typedef struct QIOChannelCommand QIOChannelCommand;
/**
* QIOChannelCommand:
*
* The QIOChannelCommand class provides a channel implementation
* that can transport data with an externally running command
* via its stdio streams.
*/
struct QIOChannelCommand {
QIOChannel parent;
int writefd;
int readfd;
pid_t pid;
};
/**
* qio_channel_command_new_pid:
* @writefd: the FD connected to the command's stdin
* @readfd: the FD connected to the command's stdout
* @pid: the PID of the running child command
* @errp: pointer to a NULL-initialized error object
*
* Create a channel for performing I/O with the
* previously spawned command identified by @pid.
* The two file descriptors provide the connection
* to command's stdio streams, either one or which
* may be -1 to indicate that stream is not open.
*
* The channel will take ownership of the process
* @pid and will kill it when closing the channel.
* Similarly it will take responsibility for
* closing the file descriptors @writefd and @readfd.
*
* Returns: the command channel object, or NULL on error
*/
QIOChannelCommand *
qio_channel_command_new_pid(int writefd,
int readfd,
pid_t pid);
/**
* qio_channel_command_new_spawn:
* @argv: the NULL terminated list of command arguments
* @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
* @errp: pointer to a NULL-initialized error object
*
* Create a channel for performing I/O with the
* command to be spawned with arguments @argv.
*
* Returns: the command channel object, or NULL on error
*/
QIOChannelCommand *
qio_channel_command_new_spawn(const char *const argv[],
int flags,
Error **errp);
#endif /* QIO_CHANNEL_COMMAND_H__ */