incubator-nuttx/libs/libc/unistd/lib_getpgid.c

74 lines
2.5 KiB
C

/****************************************************************************
* libs/libc/unistd/lib_getpgid.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/sched.h>
#include <nuttx/signal.h>
#include <unistd.h>
#include <errno.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: getpgid
*
* Description:
* Get the Process Group ID of the required process id. But since NuttX do
* not support process group, so the process group id are same as process
* id, so this method will return the pid that transferred in directly,
* which is same as getpgrp() method
*
* Input parameters:
* pid - the process id that required to fetch the process group id
*
* Returned Value:
* getpgid() shall return a process group ID. Otherwise, it shall return
* (pid_t)-1 and set errno to indicate the error. If the given process id
* are invalid, set errno as EINVAL, if the given process id do not exist,
* set errno as ESRCH
*
****************************************************************************/
pid_t getpgid(pid_t pid)
{
if (pid < 0)
{
set_errno(EINVAL);
return INVALID_PROCESS_ID;
}
if (pid == 0)
{
return getpgrp();
}
else if (_SIG_KILL(pid, 0) < 0)
{
return INVALID_PROCESS_ID;
}
return pid;
}