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                 if(_IO_setvbuf(f)!=0)
  22                         return EOF;
  23                 /* fall through */
  24         case RDWR:
  25         case END:
  26                 f->rp=f->buf+f->bufl;
  27                 if(f->flags&LINEBUF){
  28                         f->wp=f->rp;
  29                         f->lp=f->buf;
  30                 }
  31                 else
  32                         f->wp=f->buf;
  33                 break;
  34         }
  35         if(first){
  36                 atexit(_IO_cleanup);
  37                 first=0;
  38         }
  39         if(f->flags&STRING){
  40                 f->rp=f->buf+f->bufl;
  41                 if(f->wp==f->rp){
  42                         if(f->flags&BALLOC){
  43                                 char *t = realloc(f->buf, f->bufl+BUFSIZ);
  44                                 if(t==NULL){
  45                                         f->state=ERR;
  46                                         return EOF;
  47                                 }
  48                                 f->buf=t;
  49                                 f->wp=t+f->bufl;
  50                                 f->bufl+=BUFSIZ;
  51                                 f->rp=t+f->bufl;
  52                         }else{
  53                                 f->state=ERR;
  54                                 return EOF;
  55                         }
  56                 }
  57                 *f->wp++=c;
  58         }
  59         else if(f->flags&LINEBUF){
  60                 if(f->lp==f->rp){
  61                         cnt=f->lp-f->buf;
  62                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  63                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  64                                 f->state=ERR;
  65                                 return EOF;
  66                         }
  67                         f->lp=f->buf;
  68                 }
  69                 *f->lp++=c;
  70                 if(c=='\n'){
  71                         cnt=f->lp-f->buf;
  72                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  73                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  74                                 f->state=ERR;
  75                                 return EOF;
  76                         }
  77                         f->lp=f->buf;
  78                 }
  79         }
  80         else if(f->buf==f->unbuf){
  81                 f->unbuf[0]=c;
  82                 if(f->flags&APPEND) seek(f->fd, 0L, 2);
  83                 if(write(f->fd, f->buf, 1)!=1){
  84                         f->state=ERR;
  85                         return EOF;
  86                 }
  87         }
  88         else{
  89                 if(f->wp==f->rp){
  90                         cnt=f->wp-f->buf;
  91                         if(f->flags&APPEND) seek(f->fd, 0L, 2);
  92                         if(cnt!=0 && write(f->fd, f->buf, cnt)!=cnt){
  93                                 f->state=ERR;
  94                                 return EOF;
  95                         }
  96                         f->wp=f->buf;
  97                         f->rp=f->buf+f->bufl;
  98                 }
  99                 *f->wp++=c;
 100         }
 101         f->state=WR;
 102         /*
 103          * Make sure EOF looks different from putc(-1)
 104          * Should be able to cast to unsigned char, but
 105          * there's a vc bug preventing that from working
 106          */
 107         return c&0xff;
 108 }