lib/ack/libp/opn.c

   1 /* $Header$ */
   2 /*
   3  * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  *
   5  *          This product is part of the Amsterdam Compiler Kit.
   6  *
   7  * Permission to use, sell, duplicate or disclose this software must be
   8  * obtained in writing. Requests for such permissions may be sent to
   9  *
  10  *      Dr. Andrew S. Tanenbaum
  11  *      Wiskundig Seminarium
  12  *      Vrije Universiteit
  13  *      Postbox 7161
  14  *      1007 MC Amsterdam
  15  *      The Netherlands
  16  *
  17  */
  18
  19 /* Author: J.W. Stevenson */
  20
  21 #include        <pc_file.h>
  22 #include        <pc_err.h>
  23
  24 extern struct file      **_extfl;
  25 extern int              _extflc;
  26 extern struct file      *_curfil;
  27 extern int              _pargc;
  28 extern char             **_pargv;
  29 extern char             ***_penviron;
  30
  31 extern                  _cls();
  32 extern                  _xcls();
  33 extern                  _trp();
  34 extern int              _getpid();
  35 extern int              _creat();
  36 extern int              _open();
  37 extern int              _close();
  38 extern int              _unlink();
  39 extern long             _lseek();
  40
  41 static int tmpfil() {
  42         static char namebuf[] = "/usr/tmp/plf.xxxxx";
  43         int i; char *p,*q;
  44
  45         i = _getpid();
  46         p = namebuf;
  47         q = p + 13;
  48         do
  49                 *q++ = (i & 07) + '0';
  50         while (i >>= 3);
  51         *q = '\0';
  52         if ((i = _creat(p,0644)) < 0)
  53                 if ((i = _creat(p += 4,0644)) < 0)
  54                         if ((i = _creat(p += 5,0644)) < 0)
  55                                 goto error;
  56         if (_close(i) != 0)
  57                 goto error;
  58         if ((i = _open(p,2)) < 0)
  59                 goto error;
  60         if (_unlink(p) != 0)
  61 error:          _trp(EREWR);
  62         return(i);
  63 }
  64
  65 static int initfl(descr,sz,f) int descr; int sz; struct file *f; {
  66         int i;
  67
  68         _curfil = f;
  69         if (sz == 0) {
  70                 sz++;
  71                 descr |= TXTBIT;
  72         }
  73         for (i=0; i<_extflc; i++)
  74                 if (f == _extfl[i])
  75                         break;
  76         if (i >= _extflc) {             /* local file */
  77                 f->fname = "LOCAL";
  78                 if ((descr & WRBIT) == 0 && (f->flags & 0377) == MAGIC) {
  79                         _xcls(f);
  80                         if (_lseek(f->ufd,(long)0,0) == -1)
  81                                 _trp(ERESET);
  82                 } else {
  83                         _cls(f);
  84                         f->ufd = tmpfil();
  85                 }
  86         } else {        /* external file */
  87                 if (--i <= 0)
  88                         return(0);
  89                 if (i >= _pargc)
  90                         _trp(EARGC);
  91                 f->fname = _pargv[i];
  92                 _cls(f);
  93                 if ((descr & WRBIT) == 0) {
  94                         if ((f->ufd = _open(f->fname,0)) < 0)
  95                                 _trp(ERESET);
  96                 } else {
  97                         if ((f->ufd = _creat(f->fname,0644)) < 0)
  98                                 _trp(EREWR);
  99                 }
 100         }
 101         f->buflen = (sz>PC_BUFLEN ? sz : PC_BUFLEN-PC_BUFLEN%sz);
 102         f->size = sz;
 103         f->ptr = f->bufadr;
 104         f->flags = descr;
 105         return(1);
 106 }
 107
 108 _opn(sz,f) int sz; struct file *f; {
 109
 110         if (initfl(MAGIC,sz,f))
 111                 f->count = 0;
 112 }
 113
 114 _cre(sz,f) int sz; struct file *f; {
 115
 116         if (initfl(WRBIT|EOFBIT|ELNBIT|MAGIC,sz,f))
 117                 f->count = f->buflen;
 118 }