sys/src/libstdio/sclose.c

   1 /*
   2  * pANS stdio -- sclose
   3  */
   4 #include "iolib.h"
   5 char *sclose(FILE *f){
   6         switch(f->state){
   7         default:        /* ERR CLOSED */
   8         Error:
   9                 if(f->buf && f->flags&BALLOC)
  10                         free(f->buf);
  11                 f->buf=0;
  12                 break;
  13         case OPEN:
  14                 f->buf=malloc(1);
  15                 f->buf[0]='\0';
  16                 break;
  17         case RD:
  18         case END:
  19                 break;
  20         case RDWR:
  21         case WR:
  22                 f->rp=f->buf+f->bufl;
  23                 if(f->wp==f->rp){
  24                         if(f->flags&BALLOC){
  25                                 char *t = realloc(f->buf, f->bufl+1);
  26                                 if(t==NULL)
  27                                         goto Error;
  28                                 f->buf=t;
  29                                 f->wp=t+f->bufl;
  30                         } else {
  31                                 if(f->wp > f->buf)
  32                                         *(f->wp-1) = '\0';
  33                                 goto Error;
  34                         }
  35                 }
  36                 *f->wp='\0';
  37                 break;
  38         }
  39         f->state=CLOSED;
  40         f->flags=0;
  41         return f->buf;
  42 }