diff options
| -rw-r--r-- | src/input.c | 30 | ||||
| -rw-r--r-- | src/input.h | 12 |
2 files changed, 34 insertions, 8 deletions
diff --git a/src/input.c b/src/input.c index 6223a73..06c08d4 100644 --- a/src/input.c +++ b/src/input.c @@ -102,10 +102,20 @@ RESET { int pgetc(void) { + int c; + + if (parsefile->unget) + return parsefile->lastc[--parsefile->unget]; + if (--parsefile->nleft >= 0) - return (signed char)*parsefile->nextc++; + c = (signed char)*parsefile->nextc++; else - return preadbuffer(); + c = preadbuffer(); + + parsefile->lastc[1] = parsefile->lastc[0]; + parsefile->lastc[0] = c; + + return c; } @@ -194,7 +204,7 @@ static int preadbuffer(void) #endif char savec; - while (unlikely(parsefile->strpush)) { + if (unlikely(parsefile->strpush)) { if ( parsefile->nleft == -1 && parsefile->strpush->ap && @@ -204,8 +214,7 @@ static int preadbuffer(void) return PEOA; } popstring(); - if (--parsefile->nleft >= 0) - return (signed char)*parsefile->nextc++; + return pgetc(); } if (unlikely(parsefile->nleft == EOF_NLEFT || parsefile->buf == NULL)) @@ -290,15 +299,14 @@ again: } /* - * Undo the last call to pgetc. Only one character may be pushed back. + * Undo a call to pgetc. Only two characters may be pushed back. * PEOF may be pushed back. */ void pungetc(void) { - parsefile->nleft++; - parsefile->nextc--; + parsefile->unget++; } /* @@ -322,6 +330,8 @@ pushstring(char *s, void *ap) sp = parsefile->strpush = &(parsefile->basestrpush); sp->prevstring = parsefile->nextc; sp->prevnleft = parsefile->nleft; + sp->unget = parsefile->unget; + memcpy(sp->lastc, parsefile->lastc, sizeof(sp->lastc)); sp->ap = (struct alias *)ap; if (ap) { ((struct alias *)ap)->flag |= ALIASINUSE; @@ -329,6 +339,7 @@ pushstring(char *s, void *ap) } parsefile->nextc = s; parsefile->nleft = len; + parsefile->unget = 0; INTON; } @@ -353,6 +364,8 @@ popstring(void) } parsefile->nextc = sp->prevstring; parsefile->nleft = sp->prevnleft; + parsefile->unget = sp->unget; + memcpy(parsefile->lastc, sp->lastc, sizeof(sp->lastc)); /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ parsefile->strpush = sp->prev; if (sp != &(parsefile->basestrpush)) @@ -439,6 +452,7 @@ pushfile(void) pf->fd = -1; pf->strpush = NULL; pf->basestrpush.prev = NULL; + pf->unget = 0; parsefile = pf; } diff --git a/src/input.h b/src/input.h index ad8b463..ec97c1d 100644 --- a/src/input.h +++ b/src/input.h @@ -49,6 +49,12 @@ struct strpush { int prevnleft; struct alias *ap; /* if push was associated with an alias */ char *string; /* remember the string since it may change */ + + /* Remember last two characters for pungetc. */ + int lastc[2]; + + /* Number of outstanding calls to pungetc. */ + int unget; }; /* @@ -66,6 +72,12 @@ struct parsefile { char *buf; /* input buffer */ struct strpush *strpush; /* for pushing strings at this level */ struct strpush basestrpush; /* so pushing one is fast */ + + /* Remember last two characters for pungetc. */ + int lastc[2]; + + /* Number of outstanding calls to pungetc. */ + int unget; }; extern struct parsefile *parsefile; |