func.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)func.c	8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if __STDC__
# include <stdarg.h>
#else
# include <varargs.h>
#endif

#include "csh.h"
#include "extern.h"
#include "pathnames.h"

extern char **environ;

static int zlast = -1;
static void	islogin __P((void));
static void	reexecute __P((struct command *));
static void	preread __P((void));
static void	doagain __P((void));
static void	search __P((int, int, Char *));
static int	getword __P((Char *));
static int	keyword __P((Char *));
static void	toend __P((void));
static void	xecho __P((int, Char **));
static void	Unsetenv __P((Char *));

struct biltins *
isbfunc(t)
    struct command *t;
{
    register Char *cp = t->t_dcom[0];
    register struct biltins *bp, *bp1, *bp2;
    static struct biltins label = {"", dozip, 0, 0};
    static struct biltins foregnd = {"%job", dofg1, 0, 0};
    static struct biltins backgnd = {"%job &", dobg1, 0, 0};

    if (lastchr(cp) == ':') {
	label.bname = short2str(cp);
	return (&label);
    }
    if (*cp == '%') {
	if (t->t_dflg & F_AMPERSAND) {
	    t->t_dflg &= ~F_AMPERSAND;
	    backgnd.bname = short2str(cp);
	    return (&backgnd);
	}
	foregnd.bname = short2str(cp);
	return (&foregnd);
    }
    /*
     * Binary search Bp1 is the beginning of the current search range. Bp2 is
     * one past the end.
     */
    for (bp1 = bfunc, bp2 = bfunc + nbfunc; bp1 < bp2;) {
	register i;

	bp = bp1 + ((bp2 - bp1) >> 1);
	if ((i = *cp - *bp->bname) == 0 &&
	    (i = Strcmp(cp, str2short(bp->bname))) == 0)
	    return bp;
	if (i < 0)
	    bp2 = bp;
	else
	    bp1 = bp + 1;
    }
    return (0);
}

void
func(t, bp)
    register struct command *t;
    register struct biltins *bp;
{
    int     i;

    xechoit(t->t_dcom);
    setname(bp->bname);
    i = blklen(t->t_dcom) - 1;
    if (i < bp->minargs)
	stderror(ERR_NAME | ERR_TOOFEW);
    if (i > bp->maxargs)
	stderror(ERR_NAME | ERR_TOOMANY);
    (*bp->bfunct) (t->t_dcom, t);
}

void
/*ARGSUSED*/
doonintr(v, t)
    Char **v;
    struct command *t;
{
    register Char *cp;
    register Char *vv = v[1];

    if (parintr == SIG_IGN)
	return;
    if (setintr && intty)
	stderror(ERR_NAME | ERR_TERMINAL);
    cp = gointr;
    gointr = 0;
    xfree((ptr_t) cp);
    if (vv == 0) {
	if (setintr)
	    (void) sigblock(sigmask(SIGINT));
	else
	    (void) signal(SIGINT, SIG_DFL);
	gointr = 0;
    }
    else if (eq((vv = strip(vv)), STRminus)) {
	(void) signal(SIGINT, SIG_IGN);
	gointr = Strsave(STRminus);
    }
    else {
	gointr = Strsave(vv);
	(void) signal(SIGINT, pintr);
    }
}

void
/*ARGSUSED*/
donohup(v, t)
    Char **v;
    struct command *t;
{
    if (intty)
	stderror(ERR_NAME | ERR_TERMINAL);
    if (setintr == 0) {
	(void) signal(SIGHUP, SIG_IGN);
    }
}

void
/*ARGSUSED*/
dozip(v, t)
    Char **v;
    struct command *t;
{
    ;
}

void
prvars()
{
    plist(&shvhed);
}

void
/*ARGSUSED*/
doalias(v, t)
    Char **v;
    struct command *t;
{
    register struct varent *vp;
    register Char *p;

    v++;
    p = *v++;
    if (p == 0)
	plist(&aliases);
    else if (*v == 0) {
	vp = adrof1(strip(p), &aliases);
	if (vp) {
	    blkpr(cshout, vp->vec);
	    fputc('\n', cshout);
	}
    }
    else {
	if (eq(p, STRalias) || eq(p, STRunalias)) {
	    setname(vis_str(p));
	    stderror(ERR_NAME | ERR_DANGER);
	}
	set1(strip(p), saveblk(v), &aliases);
    }
}

void
/*ARGSUSED*/
unalias(v, t)
    Char **v;
    struct command *t;
{
    unset1(v, &aliases);
}

void
/*ARGSUSED*/
dologout(v, t)
    Char **v;
    struct command *t;
{
    islogin();
    goodbye();
}

void
/*ARGSUSED*/
dologin(v, t)
    Char **v;
    struct command *t;
{
    islogin();
    rechist();
    (void) signal(SIGTERM, parterm);
    (void) execl(_PATH_LOGIN, "login", short2str(v[1]), NULL);
    untty();
    xexit(1);
}

static void
islogin()
{
    if (chkstop == 0 && setintr)
	panystop(0);
    if (loginsh)
	return;
    stderror(ERR_NOTLOGIN);
}

void
doif(v, kp)
    Char  **v;
    struct command *kp;
{
    register int i;
    register Char **vv;

    v++;
    i = expr(&v);
    vv = v;
    if (*vv == NULL)
	stderror(ERR_NAME | ERR_EMPTYIF);
    if (eq(*vv, STRthen)) {
	if (*++vv)
	    stderror(ERR_NAME | ERR_IMPRTHEN);
	setname(vis_str(STRthen));
	/*
	 * If expression was zero, then scan to else, otherwise just fall into
	 * following code.
	 */
	if (!i)
	    search(T_IF, 0, NULL);
	return;
    }
    /*
     * Simple command attached to this if. Left shift the node in this tree,
     * munging it so we can reexecute it.
     */
    if (i) {
	lshift(kp->t_dcom, vv - kp->t_dcom);
	reexecute(kp);
	donefds();
    }
}

/*
 * Reexecute a command, being careful not
 * to redo i/o redirection, which is already set up.
 */
static void
reexecute(kp)
    register struct command *kp;
{
    kp->t_dflg &= F_SAVE;
    kp->t_dflg |= F_REPEAT;
    /*
     * If tty is still ours to arbitrate, arbitrate it; otherwise dont even set
     * pgrp's as the jobs would then have no way to get the tty (we can't give
     * it to them, and our parent wouldn't know their pgrp, etc.
     */
    execute(kp, (tpgrp > 0 ? tpgrp : -1), NULL, NULL);
}

void
/*ARGSUSED*/
doelse(v, t)
    Char **v;
    struct command *t;
{
    search(T_ELSE, 0, NULL);
}

void
/*ARGSUSED*/
dogoto(v, t)
    Char **v;
    struct command *t;
{
    Char   *lp;

    gotolab(lp = globone(v[1], G_ERROR));
    xfree((ptr_t) lp);
}

void
gotolab(lab)
    Char *lab;
{
    register struct whyle *wp;
    /*
     * While we still can, locate any unknown ends of existing loops. This
     * obscure code is the WORST result of the fact that we don't really parse.
     */
    zlast = T_GOTO;
    for (wp = whyles; wp; wp = wp->w_next)
	if (wp->w_end.type == F_SEEK && wp->w_end.f_seek == 0) {
	    search(T_BREAK, 0, NULL);
	    btell(&wp->w_end);
	}
	else
	    bseek(&wp->w_end);
    search(T_GOTO, 0, lab);
    /*
     * Eliminate loops which were exited.
     */
    wfree();
}

void
/*ARGSUSED*/
doswitch(v, t)
    Char **v;
    struct command *t;
{
    register Char *cp, *lp;

    v++;
    if (!*v || *(*v++) != '(')
	stderror(ERR_SYNTAX);
    cp = **v == ')' ? STRNULL : *v++;
    if (*(*v++) != ')')
	v--;
    if (*v)
	stderror(ERR_SYNTAX);
    search(T_SWITCH, 0, lp = globone(cp, G_ERROR));
    xfree((ptr_t) lp);
}

void
/*ARGSUSED*/
dobreak(v, t)
    Char **v;
    struct command *t;
{
    if (whyles)
	toend();
    else
	stderror(ERR_NAME | ERR_NOTWHILE);
}

void
/*ARGSUSED*/
doexit(v, t)
    Char **v;
    struct command *t;
{
    if (chkstop == 0 && (intty || intact) && evalvec == 0)
	panystop(0);
    /*
     * Don't DEMAND parentheses here either.
     */
    v++;
    if (*v) {
	set(STRstatus, putn(expr(&v)));
	if (*v)
	    stderror(ERR_NAME | ERR_EXPRESSION);
    }
    btoeof();
    if (intty)
	(void) close(SHIN);
}

void
/*ARGSUSED*/
doforeach(v, t)
    Char **v;
    struct command *t;
{
    register Char *cp, *sp;
    register struct whyle *nwp;

    v++;
    sp = cp = strip(*v);
    if (!letter(*sp))
	stderror(ERR_NAME | ERR_VARBEGIN);
    while (*cp && alnum(*cp))
	cp++;
    if (*cp)
	stderror(ERR_NAME | ERR_VARALNUM);
    if ((cp - sp) > MAXVARLEN)
	stderror(ERR_NAME | ERR_VARTOOLONG);
    cp = *v++;
    if (v[0][0] != '(' || v[blklen(v) - 1][0] != ')')
	stderror(ERR_NAME | ERR_NOPAREN);
    v++;
    gflag = 0, tglob(v);
    v = globall(v);
    if (v == 0)
	stderror(ERR_NAME | ERR_NOMATCH);
    nwp = (struct whyle *) xcalloc(1, sizeof *nwp);
    nwp->w_fe = nwp->w_fe0 = v;
    gargv = 0;
    btell(&nwp->w_start);
    nwp->w_fename = Strsave(cp);
    nwp->w_next = whyles;
    nwp->w_end.type = F_SEEK;
    whyles = nwp;
    /*
     * Pre-read the loop so as to be more comprehensible to a terminal user.
     */
    zlast = T_FOREACH;
    if (intty)
	preread();
    doagain();
}

void
/*ARGSUSED*/
dowhile(v, t)
    Char **v;
    struct command *t;
{
    register int status;
    register bool again = whyles != 0 && SEEKEQ(&whyles->w_start, &lineloc) &&
    whyles->w_fename == 0;

    v++;
    /*
     * Implement prereading here also, taking care not to evaluate the
     * expression before the loop has been read up from a terminal.
     */
    if (intty && !again)
	status = !exp0(&v, 1);
    else
	status = !expr(&v);
    if (*v)
	stderror(ERR_NAME | ERR_EXPRESSION);
    if (!again) {
	register struct whyle *nwp =
	(struct whyle *) xcalloc(1, sizeof(*nwp));

	nwp->w_start = lineloc;
	nwp->w_end.type = F_SEEK;
	nwp->w_end.f_seek = 0;
	nwp->w_next = whyles;
	whyles = nwp;
	zlast = T_WHILE;
	if (intty) {
	    /*
	     * The tty preread
	     */
	    preread();
	    doagain();
	    return;
	}
    }
    if (status)
	/* We ain't gonna loop no more, no more! */
	toend();
}

static void
preread()
{
    whyles->w_end.type = I_SEEK;
    if (setintr)
	(void) sigsetmask(sigblock((sigset_t) 0) & ~sigmask(SIGINT));

    search(T_BREAK, 0, NULL);		/* read the expression in */
    if (setintr)
	(void) sigblock(sigmask(SIGINT));
    btell(&whyles->w_end);
}

void
/*ARGSUSED*/
doend(v, t)
    Char **v;
    struct command *t;
{
    if (!whyles)
	stderror(ERR_NAME | ERR_NOTWHILE);
    btell(&whyles->w_end);
    doagain();
}

void
/*ARGSUSED*/
docontin(v, t)
    Char **v;
    struct command *t;
{
    if (!whyles)
	stderror(ERR_NAME | ERR_NOTWHILE);
    doagain();
}

static void
doagain()
{
    /* Repeating a while is simple */
    if (whyles->w_fename == 0) {
	bseek(&whyles->w_start);
	return;
    }
    /*
     * The foreach variable list actually has a spurious word ")" at the end of
     * the w_fe list.  Thus we are at the of the list if one word beyond this
     * is 0.
     */
    if (!whyles->w_fe[1]) {
	dobreak(NULL, NULL);
	return;
    }
    set(whyles->w_fename, Strsave(*whyles->w_fe++));
    bseek(&whyles->w_start);
}

void
dorepeat(v, kp)
    Char  **v;
    struct command *kp;
{
    register int i;
    register sigset_t omask = 0;

    i = getn(v[1]);
    if (setintr)
	omask = sigblock(sigmask(SIGINT)) & ~sigmask(SIGINT);
    lshift(v, 2);
    while (i > 0) {
	if (setintr)
	    (void) sigsetmask(omask);
	reexecute(kp);
	--i;
    }
    donefds();
    if (setintr)
	(void) sigsetmask(omask);
}

void
/*ARGSUSED*/
doswbrk(v, t)
    Char **v;
    struct command *t;
{
    search(T_BRKSW, 0, NULL);
}

int
srchx(cp)
    register Char *cp;
{
    register struct srch *sp, *sp1, *sp2;
    register i;

    /*
     * Binary search Sp1 is the beginning of the current search range. Sp2 is
     * one past the end.
     */
    for (sp1 = srchn, sp2 = srchn + nsrchn; sp1 < sp2;) {
	sp = sp1 + ((sp2 - sp1) >> 1);
	if ((i = *cp - *sp->s_name) == 0 &&
	    (i = Strcmp(cp, str2short(sp->s_name))) == 0)
	    return sp->s_value;
	if (i < 0)
	    sp2 = sp;
	else
	    sp1 = sp + 1;
    }
    return (-1);
}

static Char Stype;
static Char *Sgoal;

/*VARARGS2*/
static void
search(type, level, goal)
    int     type;
    register int level;
    Char   *goal;
{
    Char    wordbuf[BUFSIZ];
    register Char *aword = wordbuf;
    register Char *cp;

    Stype = type;
    Sgoal = goal;
    if (type == T_GOTO) {
	struct Ain a;
	a.type = F_SEEK;
	a.f_seek = 0;
	bseek(&a);
    }
    do {
	if (intty && fseekp == feobp && aret == F_SEEK)
	    (void) fprintf(cshout, "? "), (void) fflush(cshout);
	aword[0] = 0;
	(void) getword(aword);
	switch (srchx(aword)) {

	case T_ELSE:
	    if (level == 0 && type == T_IF)
		return;
	    break;

	case T_IF:
	    while (getword(aword))
		continue;
	    if ((type == T_IF || type == T_ELSE) &&
		eq(aword, STRthen))
		level++;
	    break;

	case T_ENDIF:
	    if (type == T_IF || type == T_ELSE)
		level--;
	    break;

	case T_FOREACH:
	case T_WHILE:
	    if (type == T_BREAK)
		level++;
	    break;

	case T_END:
	    if (type == T_BREAK)
		level--;
	    break;

	case T_SWITCH:
	    if (type == T_SWITCH || type == T_BRKSW)
		level++;
	    break;

	case T_ENDSW:
	    if (type == T_SWITCH || type == T_BRKSW)
		level--;
	    break;

	case T_LABEL:
	    if (type == T_GOTO && getword(aword) && eq(aword, goal))
		level = -1;
	    break;

	default:
	    if (type != T_GOTO && (type != T_SWITCH || level != 0))
		break;
	    if (lastchr(aword) != ':')
		break;
	    aword[Strlen(aword) - 1] = 0;
	    if ((type == T_GOTO && eq(aword, goal)) ||
		(type == T_SWITCH && eq(aword, STRdefault)))
		level = -1;
	    break;

	case T_CASE:
	    if (type != T_SWITCH || level != 0)
		break;
	    (void) getword(aword);
	    if (lastchr(aword) == ':')
		aword[Strlen(aword) - 1] = 0;
	    cp = strip(Dfix1(aword));
	    if (Gmatch(goal, cp))
		level = -1;
	    xfree((ptr_t) cp);
	    break;

	case T_DEFAULT:
	    if (type == T_SWITCH && level == 0)
		level = -1;
	    break;
	}
	(void) getword(NULL);
    } while (level >= 0);
}

static int
getword(wp)
    register Char *wp;
{
    register int found = 0;
    register int c, d;
    int     kwd = 0;
    Char   *owp = wp;

    c = readc(1);
    d = 0;
    do {
	while (c == ' ' || c == '\t')
	    c = readc(1);
	if (c == '#')
	    do
		c = readc(1);
	    while (c >= 0 && c != '\n');
	if (c < 0)
	    goto past;
	if (c == '\n') {
	    if (wp)
		break;
	    return (0);
	}
	unreadc(c);
	found = 1;
	do {
	    c = readc(1);
	    if (c == '\\' && (c = readc(1)) == '\n')