apps/lib/libmeinos/execute.c

   1 /*
   2     meinOS - A unix-like x86 microkernel operating system
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <sys/types.h>
  20 #include <sys/shm.h>
  21 #include <rpc.h>
  22 #include <misc.h>
  23 #include <string.h>
  24
  25 int _create_unnamed_pipe(int read,int *_shmid);
  26
  27 /**
  28  * Creates a new process from executable file
  29  *  @param path Path to executable
  30  *  @param argv Argument vector
  31  *  @param stdin Reference for filehandle for stdin of new process
  32  *  @param stdout Reference for filehandle for stdout of new process
  33  *  @param stderr Reference for filehandle for stderr of new process
  34  *  @return PID of new process
  35  */
  36 pid_t execute(const char *path,char *argv[],int *_stdin,int *_stdout,int *_stderr) {
  37   size_t shmsize = sizeof(struct process_data)+1;
  38   int shmid;
  39   struct process_data *data;
  40   size_t i;
  41
  42   if (argv!=NULL) {
  43     for (i=0;argv[i];i++) shmsize += strlen(argv[i])+1;
  44   }
  45   shmid = shmget(IPC_PRIVATE,shmsize,0);
  46
  47   if (shmid!=-1) {
  48     data = shmat(shmid,NULL,0);
  49     if (data!=NULL) {
  50       int stdin = _create_unnamed_pipe(0,&(data->shmid_stdin));
  51       int stdout = _create_unnamed_pipe(1,&(data->shmid_stdout));
  52       int stderr = _create_unnamed_pipe(1,&(data->shmid_stderr));
  53       if (_stdin!=NULL) *_stdin = stdin;
  54       if (_stdout!=NULL) *_stdout = stdout;
  55       if (_stderr!=NULL) *_stderr = stderr;
  56
  57       size_t j = 0;
  58       if (argv!=NULL) {
  59
  60         for (i=0;argv[i];i++) {
  61           strcpy(data->cmdline+j,argv[i]);
  62           j += strlen(data->cmdline+j)+1;
  63         }
  64       }
  65       data->cmdline[j] = 0;
  66
  67       shmdt(data);
  68
  69       return rpc_call("proc_execute",0,path,shmid);
  70     }
  71   }
  72   return -1;
  73 }