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[unix-history] / usr / src / libI77 / open.c

#include        "sys/types.h"
#include        "sys/stat.h"
#include "fio.h"
f_open(a) olist *a;
{       unit *b;
       int n;
       char buf[256];
       cllist x;
       if(a->ounit>=MXUNIT || a->ounit<0)
               err(a->oerr,101,"open")
       b= &units[a->ounit];
       if(b->ufd!=0) goto connected;
unconnected:
       b->url=a->orl;
       if(*a->oblnk=='b') b->ublnk=1;
       else b->ublnk=0;
       if(a->ofm==0)
       {       if(b->url>0) b->ufmt=0;
               else b->ufmt=1;
       }
       else if(*a->ofm=='f') b->ufmt=1;
       else b->ufmt=0;
       if(a->osta==0) goto unknown;
       switch(*a->osta)
       {
       unknown:
       default:
       case 'o':
               if(a->ofnm==0) err(a->oerr,107,"open")
               g_char(a->ofnm,a->ofnmlen,buf);
               b->uscrtch=0;
               if(*a->osta=='o' && access(buf,0))
                       err(a->oerr,errno,"open")
       done:
               b->ufnm=(char *) calloc(strlen(buf)+1,sizeof(char));
               if(b->ufnm==NULL) err(a->oerr,113,"no space");
               strcpy(b->ufnm,buf);
               b->uend=0;
               if(isdev(buf))
               {       b->ufd = fopen(buf,"r");
                       if(b->ufd==NULL) err(a->oerr,errno,buf)
                       else    b->uwrt = 0;
               }
               else
               {       b->ufd = fopen(buf, "a");
                       if(b->ufd != NULL) b->uwrt = 1;
                       else if((b->ufd = fopen(buf, "r")) != NULL)
                       {       fseek(b->ufd, 0L, 2);
                               b->uwrt = 0;
                       }
                       else    err(a->oerr, errno, buf)
               }
               b->useek=canseek(b->ufd);
               if((b->uinode=inode(buf))==-1)
                       err(a->oerr,108,"open")
               if(a->orl && b->useek) rewind(b->ufd);
               return(0);
        case 's':
               b->uscrtch=1;
               strcpy(buf,"tmp.FXXXXXX");
               mktemp(buf);
               goto done;
       case 'n':
               b->uscrtch=0;
               if(a->ofnm==0) err(a->oerr,107,"open")
               g_char(a->ofnm,a->ofnmlen,buf);
               /*SYSDEP access*/
               if(access(buf, 0) == 0) creat(buf, 0666);
               goto done;
       }
connected:
       if(a->ofnm==0)
       {
       same:   if(a->oblnk!= 0) b->ublnk= *a->oblnk== 'b'?0:1;
               return(0);
       }
       g_char(a->ofnm,a->ofnmlen,buf);
       if(inode(buf)==b->uinode) goto same;
       x.cunit=a->ounit;
       x.csta=0;
       x.cerr=a->oerr;
       if((n=f_clos(&x))!=0) return(n);
       goto unconnected;
}
fk_open(rd,seq,fmt,n) ftnint n;
{       char nbuf[10];
       olist a;
       sprintf(nbuf,"fort.%D",n);
       a.oerr=1;
       a.ounit=n;
       a.ofnm=nbuf;
       a.ofnmlen=strlen(nbuf);
       a.osta=NULL;
       a.oacc= seq==SEQ?"s":"d";
       a.ofm = fmt==FMT?"f":"u";
       a.orl = seq==DIR?1:0;
       a.oblnk=NULL;
       return(f_open(&a));
}
isdev(s) char *s;
{       struct stat x;
       int j;
       if(stat(s, &x) == -1) return(0);
       if((j = (x.st_mode&S_IFMT)) == S_IFREG || j == S_IFDIR) return(0);
       else    return(1);
}