#include "rc.h"#include "exec.h"#include "io.h"#include "getflags.h"#include "fns.h"int getnext(void); intwordchr(int c){	return !strchr("\n \t#;&|^$=`'{}()<>", c) && c!=EOF;} intidchr(int c){	/*	 * Formerly:	 * return 'a'<=c && c<='z' || 'A'<=c && c<='Z' || '0'<=c && c<='9'	 *	|| c=='_' || c=='*';	 */	return c>' ' && !strchr("!\"#$%&'()+,-./:;<=>?@[\\]^`{|}~", c);}int future = EOF;int doprompt = 1;int inquote;int incomm;/* * Look ahead in the input stream */ intnextc(void){	if(future==EOF)		future = getnext();	return future;}/* * Consume the lookahead character. */ intadvance(void){	int c = nextc();	lastc = future;	future = EOF;	return c;}/* * read a character from the input stream */	 intgetnext(void){	int c;	static int peekc = EOF;	if(peekc!=EOF){		c = peekc;		peekc = EOF;		return c;	}	if(runq->eof)		return EOF;	if(doprompt)		pprompt();	c = rchr(runq->cmdfd);	if(!inquote && c=='\\'){		c = rchr(runq->cmdfd);		if(c=='\n' && !incomm){		/* don't continue a comment */			doprompt = 1;			c=' ';		}		else{			peekc = c;			c='\\';		}	}	doprompt = doprompt || c=='\n' || c==EOF;	if(c==EOF)		runq->eof++;	else if(flag['V'] || ndot>=2 && flag['v']) pchr(err, c);	return c;} voidpprompt(void){	var *prompt;	if(runq->iflag){		pstr(err, promptstr);		flush(err);		prompt = vlook("prompt");		if(prompt->val && prompt->val->next)			promptstr = prompt->val->next->word;		else			promptstr="\t";	}	runq->lineno++;	doprompt = 0;} voidskipwhite(void){	int c;	for(;;){		c = nextc();		/* Why did this used to be  if(!inquote && c=='#') ?? */		if(c=='#'){			incomm = 1;			for(;;){				c = nextc();				if(c=='\n' || c==EOF) {					incomm = 0;					break;				}				advance();			}		}		if(c==' ' || c=='\t')			advance();		else return;	}} voidskipnl(void){	int c;	for(;;){		skipwhite();		c = nextc();		if(c!='\n')			return;		advance();	}} intnextis(int c){	if(nextc()==c){		advance();		return 1;	}	return 0;} char*addtok(char *p, int val){	if(p==0)		return 0;	if(p==&tok[NTOK-1]){		*p = 0;		yyerror("token buffer too short");		return 0;	}	*p++=val;	return p;} char*addutf(char *p, int c){	p = addtok(p, c);	if(twobyte(c))	 /* 2-byte escape */		return addtok(p, advance());	if(threebyte(c)){	/* 3-byte escape */		p = addtok(p, advance());		return addtok(p, advance());	}	return p;}int lastdol;	/* was the last token read '$' or '$#' or '"'? */int lastword;	/* was the last token read a word or compound word terminator? */ intyylex(void){	int c, d = nextc();	char *w = tok;	struct tree *t;	yylval.tree = 0;	/*	 * Embarassing sneakiness:  if the last token read was a quoted or unquoted	 * WORD then we alter the meaning of what follows.  If the next character	 * is `(', we return SUB (a subscript paren) and consume the `('.  Otherwise,	 * if the next character is the first character of a simple or compound word,	 * we insert a `^' before it.	 */	if(lastword){		lastword = 0;		if(d=='('){			advance();			strcpy(tok, "( [SUB]");			return SUB;		}		if(wordchr(d) || d=='\'' || d=='`' || d=='$' || d=='"'){			strcpy(tok, "^");			return '^';		}	}	inquote = 0;	skipwhite();	switch(c = advance()){	case EOF:		lastdol = 0;		strcpy(tok, "EOF");		return EOF;	case '$':		lastdol = 1;		if(nextis('#')){			strcpy(tok, "$#");			return COUNT;		}		if(nextis('"')){			strcpy(tok, "$\"");			return '"';		}		strcpy(tok, "$");		return '$';	case '&':		lastdol = 0;		if(nextis('&')){			skipnl();			strcpy(tok, "&&");			return ANDAND;		}		strcpy(tok, "&");		return '&';	case '|':		lastdol = 0;		if(nextis(c)){			skipnl();			strcpy(tok, "||");			return OROR;		}	case '<':	case '>':		lastdol = 0;		/*		 * funny redirection tokens:		 *	redir:	arrow | arrow '[' fd ']'		 *	arrow:	'<' | '<<' | '>' | '>>' | '|'		 *	fd:	digit | digit '=' | digit '=' digit		 *	digit:	'0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'		 * some possibilities are nonsensical and get a message.		 */		*w++=c;		t = newtree();		switch(c){		case '|':			t->type = PIPE;			if(nextis('<'))				t->type = FANOUT;						t->fd0 = 1;			t->fd1 = 0;			break;		case '>':			t->type = REDIR;			if(nextis('|')){				t->type = FANIN;				t->fd0 = 1;				t->fd1 = 0;				break;			}			if(nextis(c)){				t->rtype = APPEND;				*w++=c;			}			else t->rtype = WRITE;			t->fd0 = 1;			t->fd1 = 0;			break;		case '<':			t->type = REDIR;			if(nextis(c)){				t->rtype = HERE;				*w++=c;			} else if (nextis('>')){				t->rtype = RDWR;				*w++=c;			} else t->rtype = READ;			t->fd0 = 1;			t->fd1 = 0;			break;		}		if(nextis('[')){			*w++='[';			c = advance();			*w++=c;			if(c<'0' || '9'<c){			RedirErr:				*w = 0;				yyerror(t->type==PIPE||					t->type==FANOUT||					t->type==FANIN					?"pipe syntax"						:"redirection syntax");				return EOF;			}			t->fd0 = 0;			do{				t->fd0 = t->fd0*10+c-'0';				*w++=c;				c = advance();			}while('0'<=c && c<='9');			if(c=='='){				*w++='=';				if(t->type==REDIR)					t->type = DUP;				c = advance();				if('0'<=c && c<='9'){					t->rtype = DUPFD;					t->fd1 = t->fd0;					t->fd0 = 0;					do{						t->fd0 = t->fd0*10+c-'0';						*w++=c;						c = advance();					}while('0'<=c && c<='9');				}				else{					if(t->type==PIPE)						goto RedirErr;					t->rtype = CLOSE;				}			}			if(c!=']'			|| t->type==DUP && (t->rtype==HERE || t->rtype==APPEND))				goto RedirErr;			*w++=']';		}		*w='\0';		yylval.tree = t;		if(t->type==PIPE)			skipnl();		return t->type;	case '\'':		lastdol = 0;		lastword = 1;		inquote = 1;		for(;;){			c = advance();			if(c==EOF)				break;			if(c=='\''){				if(nextc()!='\'')					break;				advance();			}			w = addutf(w, c);		}		if(w!=0)			*w='\0';		t = token(tok, WORD);		t->quoted = 1;		yylval.tree = t;		return t->type;	}	if(!wordchr(c)){		lastdol = 0;		tok[0] = c;		tok[1]='\0';		return c;	}	for(;;){		/* next line should have (char)c==GLOB, but ken's compiler is broken */		if(c=='*' || c=='[' || c=='?' || c==(unsigned char)GLOB)			w = addtok(w, GLOB);		w = addutf(w, c);		c = nextc();		if(lastdol?!idchr(c):!wordchr(c)) break;		advance();	} 	lastword = 1;	lastdol = 0;	if(w!=0)		*w='\0';	t = klook(tok);	if(t->type!=WORD)		lastword = 0;	t->quoted = 0;	yylval.tree = t;	return t->type;}