sys/src/libstdio/_IO_putc.c

   1 /*
   2  * pANS stdio -- _IO_putc, _IO_cleanup
   3  */
   4 #include "iolib.h"
   5 void _IO_cleanup(void){
   6         fflush(NULL);
   7 }
   8 /*
   9  * Look this over for simplification
  10  */
  11 int _IO_putc(int c, FILE *f){
  12         int cnt;
  13         static int first=1;
  14         switch(f->state){
  15         case RD:
  16                 f->state=ERR;
  17         case ERR:
  18         case CLOSED:
  19                 return EOF;
  20         case OPEN:
  21                 _IO_setvbuf(f);
  22                 /* fall through */
  23         case RDWR:
  24         case END:
  25                 f->rp=f->buf+f->bufl;
  26                 if(f->flags&LINEBUF){
  27                         f->wp=f->rp;
  28                         f->lp=f->buf;
  29                 }
  30                 else
  31                         f->wp=f->buf;
  32                 break;
  33         }
  34         if(first){
  35                 atexit(_IO_cleanup);
  36                 first=0;
  37         }
  38         if(f->flags&STRING){
  39                 f->rp=f->buf+f->bufl;
  40                 if(f->wp==f->rp){
  41                         if(f->flags&BALLOC)
  42                                 f->buf=realloc(f->buf, f->bufl+BUFSIZ);
  43                         else{
  44                                 f->state=ERR;
  45                                 return EOF;
  46                         }
  47                         if(f->buf==NULL){
  48                                 f->state=ERR;
  49                                 return EOF;
  50                         }
  51                         f->rp=f->buf+f->bufl;
  52                         f->bufl+=BUFSIZ;
  53                 }
  54                 *f->wp++=c;
  55         }
  56         else if(f->flags&LINEBUF){
  57                 if(f->lp==f->rp){
  58                         cnt=f->lp-f->buf;
  59                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  60                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  61                                 f->state=ERR;
  62                                 return EOF;
  63                         }
  64                         f->lp=f->buf;
  65                 }
  66                 *f->lp++=c;
  67                 if(c=='\n'){
  68                         cnt=f->lp-f->buf;
  69                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  70                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  71                                 f->state=ERR;
  72                                 return EOF;
  73                         }
  74                         f->lp=f->buf;
  75                 }
  76         }
  77         else if(f->buf==f->unbuf){
  78                 f->unbuf[0]=c;
  79                 if(f->flags&APPEND) seek(f->fd, 0L, 2);
  80                 if(write(f->fd, f->buf, 1)!=1){
  81                         f->state=ERR;
  82                         return EOF;
  83                 }
  84         }
  85         else{
  86                 if(f->wp==f->rp){
  87                         cnt=f->wp-f->buf;
  88                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  89                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  90                                 f->state=ERR;
  91                                 return EOF;
  92                         }
  93                         f->wp=f->buf;
  94                         f->rp=f->buf+f->bufl;
  95                 }
  96                 *f->wp++=c;
  97         }
  98         f->state=WR;
  99         /*
 100          * Make sure EOF looks different from putc(-1)
 101          * Should be able to cast to unsigned char, but
 102          * there's a vc bug preventing that from working
 103          */
 104         return c&0xff;
 105 }