cde/programs/dtksh/ksh93/src/lib/libast/sfio/sfpopen.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these librararies and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /* $XConsortium: sfpopen.c /main/3 1995/11/01 18:33:06 rswiston $ */
  24 /***************************************************************
  25 *                                                              *
  26 *                      AT&T - PROPRIETARY                      *
  27 *                                                              *
  28 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
  29 *                          AT&T CORP.                          *
  30 *                                                              *
  31 *                Copyright (c) 1995 AT&T Corp.                 *
  32 *                     All Rights Reserved                      *
  33 *                                                              *
  34 *           This software is licensed by AT&T Corp.            *
  35 *       under the terms and conditions of the license in       *
  36 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  37 *                                                              *
  38 *               This software was created by the               *
  39 *           Software Engineering Research Department           *
  40 *                    AT&T Bell Laboratories                    *
  41 *                                                              *
  42 *               For further information contact                *
  43 *                     gsf@research.att.com                     *
  44 *                                                              *
  45 ***************************************************************/
  46 #include        "sfhdr.h"
  47
  48 #if _PACKAGE_ast
  49
  50 #include        <proc.h>
  51
  52 #else
  53
  54 #if _lib_vfork
  55 #define fork    vfork
  56 #if _hdr_vfork
  57 #include        <vfork.h>
  58 #endif
  59 #if _sys_vfork
  60 #include        <sys/vfork.h>
  61 #endif
  62 #endif
  63
  64 #include        <signal.h>
  65 typedef void(*Handler_t)_ARG_((int));
  66 #define EXIT_NOTFOUND   127
  67
  68 _BEGIN_EXTERNS_
  69 extern int      fork _ARG_((void));
  70 extern int      waitpid _ARG_((int, int*, int));
  71 extern int      wait _ARG_((int*));
  72 extern int      pipe _ARG_((int*));
  73 extern int      execl _ARG_((char*,char*,...));
  74 _END_EXTERNS_
  75
  76 /* pipe ends */
  77 #define READ    0
  78 #define WRITE   1
  79
  80 #endif /*_PACKAGE_ast*/
  81
  82 #if __STD_C
  83 Sfio_t *sfpopen(Sfio_t* f, const char* command, const char* mode)
  84 #else
  85 Sfio_t *sfpopen(f,command,mode)
  86 Sfio_t  *f;
  87 char    *command;       /* command to execute */
  88 char    *mode;          /* mode of the stream */
  89 #endif
  90 {
  91 #if _PACKAGE_ast
  92         reg Proc_t*     proc;
  93         reg int         sflags;
  94         reg long        flags = PROC_IGNORE;
  95         char*           av[4];
  96
  97         if (!command || !command[0] || !(sflags = _sftype(mode, NiL)))
  98                 return 0;
  99         if (sflags & SF_READ)
 100                 flags |= PROC_READ;
 101         if (sflags & SF_WRITE)
 102                 flags |= PROC_WRITE;
 103         av[0] = "sh";
 104         av[1] = "-c";
 105         av[2] = (char*)command;
 106         av[3] = 0;
 107         if (!(proc = procopen(NiL, av, NiL, NiL, flags)))
 108                 return 0;
 109         if (!(f = sfnew(f, NiL, -1, (sflags&SF_READ) ? proc->rfd : proc->wfd, sflags)) ||
 110             _sfpopen(f, (sflags&SF_READ) ? proc->wfd : -1, proc->pid) < 0)
 111         {
 112                 if (f) sfclose(f);
 113                 procclose(proc);
 114                 return 0;
 115         }
 116         procfree(proc);
 117         return f;
 118 #else
 119         reg int         pid, pkeep, ckeep, sflags;
 120         int             parent[2], child[2];
 121         Sfio_t          sf;
 122         Handler_t       sig;
 123
 124         /* sanity check */
 125         if(!command || !command[0] || !(sflags = _sftype(mode,NIL(int*))))
 126                 return NIL(Sfio_t*);
 127
 128         /* make pipes */
 129         parent[0] = parent[1] = child[0] = child[1] = -1;
 130         if(pipe(parent) < 0)
 131                 goto error;
 132         if((sflags&SF_RDWR) == SF_RDWR && pipe(child) < 0)
 133                 goto error;
 134
 135         switch(pid = fork())
 136         {
 137         default :       /* in parent process */
 138                 if(sflags&SF_READ)
 139                         { pkeep = READ; ckeep = WRITE; }
 140                 else    { pkeep = WRITE; ckeep = READ; }
 141
 142                 /* make the streams */
 143                 if(!(f = sfnew(f,NIL(char*),-1,parent[pkeep],sflags)))
 144                         goto error;
 145                 CLOSE(parent[!pkeep]);
 146
 147                 if((sflags&SF_RDWR) == SF_RDWR)
 148                         CLOSE(child[!ckeep]);
 149
 150                 /* save process info */
 151                 if(_sfpopen(f,(sflags&SF_RDWR) == SF_RDWR ? child[ckeep] : -1,pid) < 0)
 152                 {       (void)sfclose(f);
 153                         goto error;
 154                 }
 155
 156 #ifdef SIGPIPE  /* protect from broken pipe signal */
 157                 if((sflags&SF_WRITE) &&
 158                    (sig = signal(SIGPIPE,SIG_IGN)) != SIG_DFL && sig != SIG_IGN)
 159                         signal(SIGPIPE,sig);
 160 #endif
 161
 162                 return f;
 163
 164         case 0 :        /* in child process */
 165                 (void)_sfpclose(NIL(Sfio_t*));
 166
 167                 /* determine what to keep */
 168                 if(sflags&SF_READ)
 169                         { pkeep = WRITE; ckeep = READ; }
 170                 else    { pkeep = READ; ckeep = WRITE; }
 171
 172                 /* zap fd that we don't need */
 173                 CLOSE(parent[!pkeep]);
 174                 if((sflags&SF_RDWR) == SF_RDWR)
 175                         CLOSE(child[!ckeep]);
 176
 177                 /* use sfsetfd to make these descriptors the std-ones */
 178                 SFCLEAR(&sf);
 179
 180                 /* must be careful so not to close something useful */
 181                 if((sflags&SF_RDWR) == SF_RDWR && pkeep == child[ckeep])
 182                         if((child[ckeep] = dup(pkeep)) < 0)
 183                                 _exit(EXIT_NOTFOUND);
 184
 185                 if(parent[pkeep] != pkeep)
 186                 {       sf.file = parent[pkeep];
 187                         CLOSE(pkeep);
 188                         if(sfsetfd(&sf,pkeep) != pkeep)
 189                                 _exit(EXIT_NOTFOUND);
 190                 }
 191
 192                 if((sflags&SF_RDWR) == SF_RDWR && child[ckeep] != ckeep)
 193                 {       sf.file = child[ckeep];
 194                         CLOSE(ckeep);
 195                         if(sfsetfd(&sf,ckeep) != ckeep)
 196                                 _exit(EXIT_NOTFOUND);
 197                 }
 198
 199                 /* now exec the command */
 200                 execl("/bin/sh", "sh", "-c", command, NIL(char*));
 201                 _exit(EXIT_NOTFOUND);
 202                 return NIL(Sfio_t*);
 203
 204         case -1 :       /* error */
 205         error:
 206                 if(parent[0] >= 0)
 207                         { CLOSE(parent[0]); CLOSE(parent[1]); }
 208                 if(child[0] >= 0)
 209                         { CLOSE(child[0]); CLOSE(child[1]); }
 210                 return NIL(Sfio_t*);
 211         }
 212 #endif /*_PACKAGE_ast*/
 213 }