projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 520d5775 EA |
1 | # include "iodec.h" |
| 2 | ||
| 3 | /** | |
| 4 | ** get a single character | |
| 5 | **/ | |
| 6 | ||
| 7 | int __backup 0; | |
| 8 | ||
| 9 | cgetc(xfn) | |
| 10 | int xfn; | |
| 11 | { | |
| 12 | register struct fileps *fp; | |
| 13 | register int i; | |
| 14 | extern int f_log; | |
| 15 | extern int cin; | |
| 16 | register int fn; | |
| 17 | ||
| 18 | fn = xfn; | |
| 19 | if (fn < 0 || fn >= MAXFILES) | |
| 20 | __error("cgetc: illegal file number %d", fn); | |
| 21 | fp = &__filehdr[fn]; | |
| 22 | if (fp->wrflag == 2) | |
| 23 | __error("cgetc: file %d not open to read", fn); | |
| 24 | if (fp->wrflag == 0) | |
| 25 | __makbuf(fn, 0); | |
| 26 | if (fp->eoferr) | |
| 27 | return ('\0'); | |
| 28 | if (fp->nchars == 0) | |
| 29 | { | |
| 30 | i = read(fn, fp->bptr = fp->buff, fp->bsize); | |
| 31 | if (i < 0) | |
| 32 | __error("cgetc: read error on %d", fn); | |
| 33 | if (i == 0) | |
| 34 | { | |
| 35 | fp->eoferr = 2; | |
| 36 | return ('\0'); | |
| 37 | } | |
| 38 | fp->nchars = i; | |
| 39 | } | |
| 40 | fp->nchars--; | |
| 41 | if (f_log > 0 && fn == cin) | |
| 42 | if (__backup) | |
| 43 | __backup--; | |
| 44 | else | |
| 45 | cputc(*fp->bptr, f_log); | |
| 46 | return(*fp->bptr++); | |
| 47 | } |