/*
 *
 * hist.c - history expansion
 *
 * This file is part of zsh, the Z shell.
 *
 * This software is Copyright 1992 by Paul Falstad
 *
 * Permission is hereby granted to copy, reproduce, redistribute or otherwise
 * use this software as long as: there is no monetary profit gained
 * specifically from the use or reproduction of this software, it is not
 * sold, rented, traded or otherwise marketed, and this copyright notice is
 * included prominently in any copy made.
 *
 * The author make no claims as to the fitness or correctness of this software
 * for any use whatsoever, and it is provided as is. Any use of this software
 * is at the user's own risk.
 *
 */

#include "zsh.h"

static Histent curhistent;

static int lastc;

/* add a character to the current history word */

void hwaddc(c)			/**/
int c;
{
    if (hlastw && chline && (!(errflag || lexstop) || c == HISTSPACE)) {
	if (c == '!' && unset(NOBANGHIST))
	    hwaddc('\\');
	*hptr++ = c;
	if (hptr - chline >= hlinesz) {
	    int ll, flag = 0, oldsiz = hlinesz;

	    ll = hptr - hlastw;
	    if (curhistent->lex == chline)
		flag = 1;
	    chline = realloc(chline, hlinesz = oldsiz + 16);
	    if (flag)
		curhistent->lex = chline;
	    hptr = chline + oldsiz;
	    hlastw = hptr - ll;
	}
    }
}

#define habort() { errflag = lexstop = 1; return ' '; }

/* get a character after performing history substitution */

int hgetc()
{				/**/
    int c, ev, farg, evset = -1, larg, argc, cflag = 0, bflag = 0;
    static int mev = -1, marg = -1;
    char buf[256], *ptr;
    char *sline, *eline;

  tailrec:
    c = hgetch();
    if (stophist || alstackind) {
	hwaddc(c);
	return c;
    }
    if (isfirstch && c == hatchar) {
	isfirstch = 0;
	hungetch(hatchar);
	hungets(":s");
	goto hatskip;
    }
    if (c != ' ')
	isfirstch = 0;
    if (c == '\\') {
	int g = hgetch();

	if (g != bangchar)
	    hungetch(g);
	else {
	    hwaddc(bangchar);
	    return bangchar;
	}
    }
    if (c != bangchar) {
	hwaddc(c);
	return c;
    }
  hatskip:
    *hptr = '\0';
    if ((c = hgetch()) == '{') {
	bflag = cflag = 1;
	c = hgetch();
    }
    if (c == '\"') {
	stophist = 1;
	goto tailrec;
    }
    if ((!cflag && inblank(c)) || c == '=' || c == '(' || lexstop) {
	if (lexstop)
	    lexstop = 0;
	else
	    hungetch(c);
	hwaddc(bangchar);
	return bangchar;
    }
    cflag = 0;
    ptr = buf;

/* get event number */

    if (c == '?') {
	for (;;) {
	    c = hgetch();
	    if (c == '?' || c == '\n' || lexstop)
		break;
	    else
		*ptr++ = c;
	}
	if (c != '\n' && !lexstop)
	    c = hgetch();
	*ptr = '\0';
	mev = ev = hconsearch(hsubl = ztrdup(buf), &marg);
	evset = 0;
	if (ev == -1) {
	    herrflush();
	    zerr("no such event: %s", buf, 0);
	    habort();
	}
    } else {
	int t0;

	for (;;) {
	    if (inblank(c) || c == ';' || c == ':' || c == '^' || c == '$' ||
		c == '*' || c == '%' || c == '}' ||
		c == '\'' || c == '"' || c == '`' || lexstop)
		break;
	    if (ptr != buf) {
		if (c == '-')
		    break;
		if ((idigit(buf[0]) || buf[0] == '-') && !idigit(c))
		    break;
	    }
	    *ptr++ = c;
	    if (c == '#' || c == bangchar) {
		c = hgetch();
		break;
	    }
	    c = hgetch();
	}
	*ptr = 0;
	if (!*buf)
	    if (c != '%') {
		if (isset(CSHJUNKIEHISTORY))
		    ev = curhist - 1;
		else
		    ev = defev;
		if (c == ':' && evset == -1)
		    evset = 0;
		else
		    evset = 1;
	    } else {
		if (marg != -1)
		    ev = mev;
		else
		    ev = defev;
		evset = 0;
	} else if ((t0 = atoi(buf))) {
	    ev = (t0 < 0) ? curhist + t0 : t0;
	    evset = 1;
	} else if ((unsigned)*buf == bangchar) {
	    ev = curhist - 1;
	    evset = 1;
	} else if (*buf == '#') {
	    ev = curhist;
	    evset = 1;
	} else if ((ev = hcomsearch(buf)) == -1) {
	    zerr("event not found: %s", buf, 0);
	    while (c != '\n' && !lexstop)
		c = hgetch();
	    habort();
	} else
	    evset = 1;
    }

/* get the event */

    if (!(eline = getevent(defev = ev)))
	habort();

/* extract the relevant arguments */

    argc = getargc(eline);
    if (c == ':') {
	cflag = 1;
	c = hgetch();
	if (c == '%' && marg != -1) {
	    if (!evset) {
		eline = getevent(defev = mev);
		argc = getargc(eline);
	    } else {
		zerr("Ambiguous history reference", NULL, 0);
		while (c != '\n' && !lexstop)
		    c = hgetch();
		habort();
	    }

	}
    }
    if (c == '*') {
	farg = 1;
	larg = argc;
	cflag = 0;
    } else {
	hungetch(c);
	larg = farg = getargspec(argc, marg, evset);
	if (larg == -2)
	    habort();
	if (farg != -1)
	    cflag = 0;
	c = hgetch();
	if (c == '*') {
	    cflag = 0;
	    larg = argc;
	} else if (c == '-') {
	    cflag = 0;
	    larg = getargspec(argc, marg, evset);
	    if (larg == -2)
		habort();
	    if (larg == -1)
		larg = argc - 1;
	} else
	    hungetch(c);
    }
    if (farg == -1)
	farg = 0;
    if (larg == -1)
	larg = argc;
    if (!(sline = getargs(eline, farg, larg)))
	habort();

/* do the modifiers */

    for (;;) {
	c = (cflag) ? ':' : hgetch();
	cflag = 0;
	if (c == ':') {
	    int gbal = 0;

	    if ((c = hgetch()) == 'g') {
		gbal = 1;
		c = hgetch();
	    }
	    switch (c) {
	    case 'p':
		histdone = HISTFLAG_DONE | HISTFLAG_NOEXEC;
		break;
	    case 'h':
		if (!remtpath(&sline)) {
		    herrflush();
		    zerr("modifier failed: h", NULL, 0);
		    habort();
		}
		break;
	    case 'e':
		if (!rembutext(&sline)) {
		    herrflush();
		    zerr("modifier failed: e", NULL, 0);
		    habort();
		}
		break;
	    case 'r':
		if (!remtext(&sline)) {
		    herrflush();
		    zerr("modifier failed: r", NULL, 0);
		    habort();
		}
		break;
	    case 't':
		if (!remlpaths(&sline)) {
		    herrflush();
		    zerr("modifier failed: t", NULL, 0);
		    habort();
		}
		break;
	    case 's':
		{
		    int del;
		    char *ptr1, *ptr2;

		    del = hgetch();
		    ptr1 = hdynread2(del);
		    if (!ptr1)
			habort();
		    ptr2 = hdynread2(del);
		    if (strlen(ptr1)) {
			zsfree(hsubl);
			hsubl = ptr1;
		    }
		    zsfree(hsubr);
		    hsubr = ptr2;
		    if (hsubl && !ztrstr(sline, hsubl)) {
			herrflush();
			zerr("substitution failed", NULL, 0);
			habort();
		    }
		}
	    case '&':
		if (hsubl && hsubr)
		    subst(&sline, hsubl, hsubr, gbal);
		else {
		    herrflush();
		    zerr("no previous substitution with &", NULL, 0);
		    habort();
		}
		break;
	    case 'q':
		quote(&sline);
		break;
	    case 'x':
		quotebreak(&sline);
		break;
	    case 'l':
		downcase(&sline);
		break;
	    case 'u':
		upcase(&sline);
		break;
	    default:
		herrflush();
		zerr("illegal modifier: %c", NULL, c);
		habort();
	    }
	} else {
	    if (c != '}' || !bflag)
		hungetch(c);
	    if (c != '}' && bflag) {
		zerr("'}' expected", NULL, 0);
		habort();
	    }
	    break;
	}
    }

/* stuff the resulting string in the input queue and start over */

    lexstop = 0;
    if (alstackind != MAXAL) {
	hungets(HISTMARK);
	alstack[alstackind++] = NULL;
    }
    for (ptr = sline; *ptr; ptr++) {
	if (ptr[0] == '\\' && ptr[1] == '!')
	    chuck(ptr);
    }
    hungets(sline);
    histdone |= HISTFLAG_DONE;
    if (isset(HISTVERIFY))
	histdone |= HISTFLAG_NOEXEC | HISTFLAG_RECALL;
    goto tailrec;
}

/* reset the alias stack for lexrestore () */

void clearalstack()
{				/**/
    Alias ix;

    while (alstackind) {
	ix = alstack[--alstackind];
	ix->inuse = 0;
    }
}

/* get a character without history expansion */

int hgetch()
{				/**/
    unsigned char *hgetchline, *hgetchpmpt = NULL, *hgetchpmpt2 = NULL;
    int plen, p2len = 0;

  start:
    if (inbufct) {
	inbufct--;
	if ((lastc = *inbufptr++) == ALPOP && alstackind > 0) {
	    Alias ix;
	    char *t;

	    ix = alstack[--alstackind];
	    if (ix) {
		ix->inuse = 0;
		t = ix->text;
		if (*t && t[strlen(t) - 1] == ' ')
		    alstat = ALSTAT_MORE;
		else
		    alstat = ALSTAT_JUNK;
	    }
	    goto start;
	}
	if (itok(lastc))
	    goto start;
	return lastc;
    }
    if (strin || errflag) {
	lexstop = 1;
	return lastc = ' ';
    }
    if (interact && isset(SHINSTDIN))
	if (!isfirstln)
	    hgetchpmpt = (unsigned char *)putprompt(prompt2, &plen, 0);
	else {
	    hgetchpmpt = (unsigned char *)putprompt(prompt, &plen, 0);
	    if (rprompt)
		hgetchpmpt2 = (unsigned char *)putprompt(rprompt, &p2len, 0);
	    else
		hgetchpmpt2 = NULL, p2len = 0;
	}
    if (!(interact && isset(SHINSTDIN) && SHTTY != -1 && isset(USEZLE))) {
	char *lbuf;

	if (interact && isset(SHINSTDIN))
	    write(2, (WRITE_ARG_2_T) hgetchpmpt, strlen((char *)hgetchpmpt));
	hgetchline = (unsigned char *)fgets(lbuf = (char *)zalloc(256), 256, bshin);
	if (!hgetchline)
	    zfree(lbuf, 256);
    } else
	hgetchline = zleread(hgetchpmpt, hgetchpmpt2, plen, p2len);
    if (!hgetchline) {
	lexstop = 1;
	return lastc = ' ';
    }
    if (errflag) {
	free(hgetchline);
	lexstop = errflag = 1;
	return lastc = ' ';
    }
    if (interact && isset(SHINSTDIN)) {
	char *s = curhistent->lit;

	curhistent->lit = tricat("", s, (char *)hgetchline);
	zsfree(s);
    }
    if (isfirstln)
	spaceflag = *hgetchline == ' ';
    if (isset(VERBOSE)) {
	fputs((char *)hgetchline, stderr);
	fflush(stderr);
    }
    if (*hgetchline && hgetchline[strlen((char *)hgetchline) - 1] == '\n') {
	lineno++;
	if (interact && isset(SUNKEYBOARDHACK) && isset(SHINSTDIN) &&
	    SHTTY != -1 && *hgetchline && hgetchline[1] &&
	    hgetchline[strlen((char *)hgetchline) - 2] == '`') {
	    int ct;
	    unsigned char *ptr;

	    for (ct = 0, ptr = hgetchline; *ptr; ptr++)
		if (*ptr == '`')
		    ct++;
	    if (ct & 1) {
		ptr[-2] = '\n';
		ptr[-1] = '\0';
	    }
	}
    }
    isfirstch = 1;
    hungets((char *)hgetchline);
    free(hgetchline);
    goto start;
}

/* Read one line of at most n-1 chars from the input queue */

char *hgets(buf, n)		/**/
char *buf;
int n;
{
    int l;

    for (l = 0; l < n - 1; l++)
	if ((buf[l] = hgetch()) == '\n' || lexstop)
	    break;
    buf[l + (lexstop ? 0 : 1)] = 0;

    return (!lexstop || l) ? buf : NULL;
}

/* put a string in the input queue */

void hungets(str)		/**/
char *str;
{
    int slen = strlen(str);

/* shrink inbuf if it gets too big */

    if (!inbufct && inbufsz > 65536) {
	free(inbuf);
	inbuf = (char *)zalloc(inbufsz = 256);
	inbufptr = inbuf + inbufsz;
	inbufct = 0;
    }
    if (slen + inbufct > inbufsz) {
	char *x;

	while (slen + inbufct > inbufsz)
	    inbufsz *= 4;
	x = (char *)zalloc(inbufsz);
	memcpy(x + inbufsz - inbufct, inbufptr, inbufct);
	inbufptr = x + inbufsz - inbufct;
	free(inbuf);
	inbuf = x;
    }
    memcpy(inbufptr -= slen, str, slen);
    inbufct += slen;
}

/* unget a char and remove it from chline */

void hungetc(c)			/**/
int c;
{
    if (lexstop)
	return;
    if (hlastw) {
	if (hlastw == hptr)
	    zerr("hungetc attempted at buffer start", NULL, 0);
	else {
	    hptr--;
	    if (*hptr == '!' && unset(NOBANGHIST))
		hptr--;
	}
    }
    hungetch(c);
}

void hungetch(c)		/**/
int c;
{
    if (lexstop)
	return;
    if (inbufct == inbufsz) {
	hungets(" ");
	*inbufptr = c;
    } else {
	*--inbufptr = c;
	inbufct++;
    }
}

/* begin reading a string */

void strinbeg()
{				/**/
    strin = 1;
    hbegin();
    lexinit();
}

/* done reading a string */

void strinend()
{				/**/
    hend();
    strin = 0;
    isfirstch = 1;
    histdone = 0;
}

/* stuff a whole file into the input queue and print it */

int stuff(fn)			/**/
char *fn;
{
    FILE *in;
    char *buf;
    int len;

    if (!(in = fopen(fn, "r"))) {
	zerr("can't open %s", fn, 0);
	return 1;
    }
    fseek(in, 0, 2);
    len = ftell(in);
    fseek(in, 0, 0);
    buf = (char *)alloc(len + 1);
    if (!(fread(buf, len, 1, in))) {
	zerr("read error on %s", fn, 0);
	fclose(in);
	zfree(buf, len + 1);
	return 1;
    }
    fclose(in);
    buf[len] = '\0';
    fwrite(buf, len, 1, stdout);
    hungets(buf);
    return 0;
}

/* flush input queue */

void hflush()
{				/**/
    inbufptr += inbufct;
    inbufct = 0;
}

/* initialize the history mechanism */

void hbegin()
{				/**/
    isfirstln = isfirstch = 1;
    histremmed = errflag = histdone = spaceflag = 0;
    stophist = !interact || isset(NOBANGHIST) || unset(SHINSTDIN);
    lithist = isset(HISTLIT);
    chline = hptr = zcalloc(hlinesz = 16);
    curhistent = gethistent(curhist);
    if (!curhistent->ftim)
	curhistent->ftim = time(NULL);
    if (interact && isset(SHINSTDIN) && !strin) {
	attachtty(mypgrp);
	defev = curhist++;
	if (curhist - histsiz >= 0)
	    if (gethistent(curhist - histsiz)->lex) {
		zsfree(gethistent(curhist - histsiz)->lex);
		gethistent(curhist - histsiz)->lex = NULL;
	    }
	if (curhist - lithistsiz >= 0)
	    if (gethistent(curhist - lithistsiz)->lit) {
		zsfree(gethistent(curhist - lithistsiz)->lit);
		gethistent(curhist - lithistsiz)->lit = NULL;
	    }
	curhistent = gethistent(curhist);
	curhistent->lex = chline;
	*(curhistent->lit = zalloc(1)) = '\0';
    } else
	histremmed = 1;
}

/* say we're done using the history mechanism */

int hend()
{				/**/
    int flag, save = 1;
    Histent he;

    if (!chline)
	return 1;
    if (!interact || strin || unset(SHINSTDIN)) {
	zfree(chline, hlinesz);
	return 1;
    }
    flag = histdone;
    histdone = 0;
    if (hptr < chline + 2)
	save = 0;
    else {
	char *s, *t;

	s = curhistent->lit;
	if (*s && (*(t = s + strlen(s) - 1) == HISTSPACE || *t == '\n'))
	    *t = '\0';
	hptr[-1] = '\0';
	if (hptr[-2] == '\n')
	    if (chline[1]) {
		if (hptr[-3] == HISTSPACE)
		    hptr[-3] = '\0';
		else
		    hptr[-2] = '\0';
	    } else
		save = 0;
	he = gethistent(curhist - 1);
	if (!*chline || !strcmp(chline, "\n") ||
	    (isset(HISTIGNOREDUPS) && he->lex && !strcmp(he->lex, chline)) ||
	    (isset(HISTIGNORESPACE) && spaceflag))
	    save = 0;
    }
    if (flag & (HISTFLAG_DONE | HISTFLAG_RECALL)) {
	char *ptr, *p;

	p = ptr = ztrdup(chline);
	for (; *p; p++)
	    if (*p == HISTSPACE)
		*p = ' ';
	if ((flag & (HISTFLAG_DONE | HISTFLAG_RECALL)) == HISTFLAG_DONE) {
	    fprintf(stderr, "%s\n", ptr);
	    fflush(stderr);
	}
	if (flag & HISTFLAG_RECALL) {
	    permalloc();
	    pushnode(bufstack, ptr);
	    lastalloc();
	    save = 0;
	} else
	    zsfree(ptr);
    }
    curhistent->stim = time(NULL);
    curhistent->ftim = 0L;
    curhistent->flags = 0;
    if (!save)
	remhist();
    if (chline && !curhistent->lex)
	zfree(chline, hlinesz);
    if (curhistent->lex) {
	char *s = ztrdup(curhistent->lex);

	zfree(curhistent->lex, hlinesz);
	curhistent->lex = s;
    }
    chline = NULL;
    return !(flag & HISTFLAG_NOEXEC || errflag);
}

/* remove the current line from the history List */

void remhist()
{				/**/
    if (!histremmed) {
	histremmed = 1;
	curhist--;
    }
}

/* begin a word */

void hwbegin()
{				/**/
    hlastw = hptr;
}

/* add a word to the history List */

char *hwadd()
{				/**/
    if (hlastw && chline) {
	hwaddc(HISTSPACE);
	if (alstackind || strin)
	    if (!(alstackind == 1 && !alstack[0]))
		hptr = hlastw;
    }
    if (alstat == ALSTAT_JUNK)
	alstat = 0;
    return hlastw;
}

/* get an argument specification */

int getargspec(argc, marg, evset)	/**/
int argc;
int marg;
int evset;
{
    int c, ret = -1;

    if ((c = hgetch()) == '0')
	return 0;
    if (idigit(c)) {
	ret = 0;
	while (idigit(c)) {
	    ret = ret * 10 + c - '0';
	    c = hgetch();
	}
	hungetch(c);
    } else if (c == '^')
	ret = 1;
    else if (c == '$')
	ret = argc;
    else if (c == '%') {
	if (evset) {
	    herrflush();
	    zerr("Ambiguous history reference", NULL, 0);
	    return -2;
	}
	if (marg == -1) {
	    herrflush();
	    zerr("%% with no previous word matched", NULL, 0);
	    return -2;
	}
	ret = marg;
    } else
	hungetch(c);
    return ret;
}

/* do ?foo? search */

int hconsearch(str, marg)	/**/
char *str;
int *marg;
{
    int t0, t1 = 0;
    char *s, *hs;

    for (t0 = curhist - 1; (hs = quietgetevent(t0)); t0--)
	if ((s = ztrstr(hs, str))) {
	    while (s != hs)
		if (*s-- == HISTSPACE)
		    t1++;
	    *marg = t1;
	    return t0;
	}
    return -1;
}

/* do !foo search */

int hcomsearch(str)		/**/
char *str;
{
    int t0;
    char *hs;

    for (t0 = curhist - 1; (hs = quietgetevent(t0)); t0--)
	if (!strncmp(hs, str, strlen(str)))
	    return t0;
    return -1;
}

/* various utilities for : modifiers */

int remtpath(junkptr)		/**/
char **junkptr;
{
    char *str = *junkptr, *remcut;

    if ((remcut = strrchr(str, '/'))) {
	if (str != remcut)
	    *remcut = '\0';
	else
	    str[1] = '\0';
	return 1;
    }
    return 0;
}

int remtext(junkptr)		/**/
char **junkptr;
{
    char *str = *junkptr, *remcut;

    if ((remcut = strrchr(str, '.')) && remcut != str) {
	*remcut = '\0';
	return 1;
    }
    return 0;
}

int rembutext(junkptr)		/**/
char **junkptr;
{
    char *str = *junkptr, *remcut;

    if ((remcut = strrchr(str, '.')) && remcut != str) {
	*junkptr = dupstring(remcut + 1);	/* .xx or xx? */
	return 1;
    }
    return 0;
}

int remlpaths(junkptr)		/**/
char **junkptr;
{
    char *str = *junkptr, *remcut;

    if ((remcut = strrchr(str, '/'))) {
	*remcut = '\0';
	*junkptr = dupstring(remcut + 1);
	return 1;
    }
    return 0;
}

int makeuppercase(junkptr)	/**/
char **junkptr;
{
    char *str = *junkptr;

    for (; *str; str++)
	*str = tuupper(*str);
    return 1;
}

int makelowercase(junkptr)	/**/
char **junkptr;
{
    char *str = *junkptr;

    for (; *str; str++)
	*str = tulower(*str);
    return 1;
}

int makecapitals(junkptr)	/**/
char **junkptr;
{
    char *str = *junkptr;

    for (; *str;) {
	for (; *str && !ialnum(*str); str++);
	if (*str)
	    *str = tuupper(*str), str++;
	for (; *str && ialnum(*str); str++)
	    *str = tulower(*str);
    }
    return 1;
}

void subst(strptr, in, out, gbal)	/**/
char **strptr;
char *in;
char *out;
int gbal;
{
    char *str = *strptr, *instr = *strptr, *substcut, *sptr, *oldstr;
    int off, inlen, outlen;

    if (!(substcut = (char *)ztrstr(str, in)))
	return;
    inlen = strlen(in);
    sptr = convamps(out, in, inlen);
    outlen = strlen(sptr);

    do {
	*substcut = '\0';
	off = substcut - *strptr + outlen;
	substcut += inlen;
	*strptr = tricat(oldstr = *strptr, sptr, substcut);
	if (oldstr != instr)
	    zsfree(oldstr);
	str = (char *)*strptr + off;
    } while (gbal && (substcut = (char *)ztrstr(str, in)));
}

char *convamps(out, in, inlen)	/**/
char *out;
char *in;
int inlen;
{
    char *ptr, *ret, *pp;
    int slen, sdup = 0;

    for (ptr = out, slen = 0; *ptr; ptr++, slen++)
	if (*ptr == '\\')
	    ptr++, sdup = 1;
	else if (*ptr == '&')
	    slen += inlen - 1, sdup = 1;
    if (!sdup)
	return out;
    ret = pp = (char *)alloc(slen + 1);
    for (ptr = out; *ptr; ptr++)
	if (*ptr == '\\')
	    *pp++ = *++ptr;
	else if (*ptr == '&') {
	    strcpy(pp, in);
	    pp += inlen;
	} else
	    *pp++ = *ptr;
    *pp = '\0';
    return ret;
}

char *makehstr(s)		/**/
char *s;
{
    char *t;

    t = s = dupstring(s);
    for (; *t; t++)
	if (*t == HISTSPACE)
	    *t = ' ';
    return s;
}

char *quietgetevent(ev)		/**/
int ev;
{
    Histent ent;

    if (ev < firsthist() || ev > curhist)
	return NULL;
    ent = gethistent(ev);
    return (lithist) ? ent->lit : ent->lex;
}

char *getevent(ev)		/**/
int ev;
{
    char *ret;

    ret = quietgetevent(ev);
    if (!ret) {
	herrflush();
	zerr("no such event: %d", NULL, ev);
    }
    return ret;
}

int getargc(list)		/**/
char *list;
{
    int argc = 0;

    for (; *list; list++)
	if (*list == HISTSPACE)
	    argc++;
    return argc;
}

char *getargs(elist, arg1, arg2)/**/
char *elist;
int arg1;
int arg2;
{
    char *ret = elist, *retn;
    int acnt = arg2 - arg1 + 1;

    while (arg1--)
	while (*ret && *ret++ != HISTSPACE);
    if (!*ret)
	if (arg1 == -1 && arg2 == 0) {
	    herrflush();
	    zerr("no words available from current command", NULL, 0);
	    return NULL;
	} else {
	    herrflush();
	    zerr("no such word in event", NULL, 0);
	    return NULL;
	}
    retn = ret = dupstring(ret);
    while (acnt > 0) {
	while (*ret && *ret != HISTSPACE)
	    ret++;
	if (*ret == HISTSPACE)
	    *ret = ' ';
	else
	    break;
	acnt--;
    }
    if (acnt > 1 && !*ret) {
	herrflush();
	zerr("no such word in event", NULL, 0);
	return NULL;
    }
    *ret = '\0';
    return retn;
}

void upcase(x)			/**/
char **x;
{
    char *pp = *(char **)x;

    for (; *pp; pp++)
	*pp = tuupper(*pp);
}

void downcase(x)		/**/
char **x;
{
    char *pp = *(char **)x;

    for (; *pp; pp++)
	*pp = tulower(*pp);
}

int quote(tr)			/**/
char **tr;
{
    char *ptr, *rptr, **str = (char **)tr;
    int len = 3;
    int inquotes = 0;

    for (ptr = *str; *ptr; ptr++, len++)
	if (*ptr == '\'') {
	    len += 3;
	    if (!inquotes)
		inquotes = 1;
	    else
		inquotes = 0;
	} else if (inblank(*ptr) && !inquotes && ptr[-1] != '\\')
	    len += 2;
    ptr = *str;
    *str = rptr = (char *)alloc(len);
    *rptr++ = '\'';
    for (; *ptr; ptr++)
	if (*ptr == '\'') {
	    if (!inquotes)
		inquotes = 1;
	    else
		inquotes = 0;
	    *rptr++ = '\'';
	    *rptr++ = '\\';
	    *rptr++ = '\'';
	    *rptr++ = '\'';
	} else if (inblank(*ptr) && !inquotes && ptr[-1] != '\\') {
	    *rptr++ = '\'';
	    *rptr++ = *ptr;
	    *rptr++ = '\'';
	} else
	    *rptr++ = *ptr;
    *rptr++ = '\'';
    *rptr++ = 0;
    str[1] = NULL;
    return 0;
}

int quotebreak(tr)		/**/
char **tr;
{
    char *ptr, *rptr, **str = (char **)tr;
    int len = 3;

    for (ptr = *str; *ptr; ptr++, len++)
	if (*ptr == '\'')
	    len += 3;
	else if (inblank(*ptr))
	    len += 2;
    ptr = *str;
    *str = rptr = (char *)alloc(len);
    *rptr++ = '\'';
    for (; *ptr;)
	if (*ptr == '\'') {
	    *rptr++ = '\'';
	    *rptr++ = '\\';
	    *rptr++ = '\'';
	    *rptr++ = '\'';
	    ptr++;
	} else if (inblank(*ptr)) {
	    *rptr++ = '\'';
	    *rptr++ = *ptr++;
	    *rptr++ = '\'';
	} else
	    *rptr++ = *ptr++;
    *rptr++ = '\'';
    *rptr++ = '\0';
    return 0;
}

void herrflush()
{				/**/
    if (strin)
	hflush();
    else
	while (lastc != '\n' && !lexstop)
	    hgetch();
}

/* read an arbitrary amount of data into a buffer until stop is found */

char *hdynread(stop)		/**/
int stop;
{
    int bsiz = 256, ct = 0, c;
    char *buf = (char *)zalloc(bsiz), *ptr;

    ptr = buf;
    while ((c = hgetch()) != stop && c != '\n' && !lexstop) {
	if (c == '\\')
	    c = hgetch();
	*ptr++ = c;
	if (++ct == bsiz) {
	    buf = realloc(buf, bsiz *= 2);
	    ptr = buf + ct;
	}
    }
    *ptr = 0;
    if (c == '\n') {
	hungetch('\n');
	zerr("delimiter expected", NULL, 0);
	zfree(buf, bsiz);
	return NULL;
    }
    return buf;
}

char *hdynread2(stop)		/**/
int stop;
{
    int bsiz = 256, ct = 0, c;
    char *buf = (char *)zalloc(bsiz), *ptr;

    ptr = buf;
    while ((c = hgetch()) != stop && c != '\n' && !lexstop) {
	if (c == '\n') {
	    hungetch(c);
	    break;
	}
	if (c == '\\')
	    c = hgetch();
	*ptr++ = c;
	if (++ct == bsiz) {
	    buf = realloc(buf, bsiz *= 2);
	    ptr = buf + ct;
	}
    }
    *ptr = 0;
    if (c == '\n')
	hungetch('\n');
    return buf;
}

void inithist()
{				/**/
    histentct = (lithistsiz > histsiz) ? lithistsiz : histsiz;
    histentarr = (Histent) zcalloc(histentct * sizeof *histentarr);
}

void resizehistents()
{				/**/
    int newentct, t0, t1, firstlit, firstlex;
    Histent newarr;

    newentct = (lithistsiz > histsiz) ? lithistsiz : histsiz;
    newarr = (Histent) zcalloc(newentct * sizeof *newarr);
    firstlex = curhist - histsiz + 1;
    firstlit = curhist - lithistsiz + 1;
    t0 = firsthist();
    if (t0 < curhist - newentct)
	t0 = curhist - newentct;
    t1 = t0 % newentct;
    for (; t0 <= curhist; t0++) {
	newarr[t1] = *gethistent(t0);
	if (t0 < firstlex) {
	    zsfree(newarr[t1].lex);
	    newarr[t1].lex = NULL;
	}
	if (t0 < firstlit) {
	    zsfree(newarr[t1].lit);
	    newarr[t1].lit = NULL;
	}
	t1++;
	if (t1 == newentct)
	    t1 = 0;
    }
    free(histentarr);
    histentarr = newarr;
    histentct = newentct;
}

void readhistfile(s, err)	/**/
char *s;
int err;
{
    char buf[1024];
    FILE *in;
    Histent ent;
    time_t tim = time(NULL);

    if (!s)
	return;
    if ((in = fopen(s, "r"))) {
	while (fgets(buf, sizeof(buf), in)) {
	    int l = strlen(buf);
	    char *pt = buf;

	    while (l && buf[l - 1] == '\n') {
		buf[l - 1] = '\0';
		if (l > 1 && buf[l - 2] == '\\') {
		    buf[l - 2] = '\n';
		    fgets(buf + l - 1, sizeof(buf) - (l - 1), in);
		    l = strlen(buf);
		} else
		    break;
	    }
	    for (; *pt; pt++)
		if (*pt == ' ')
		    *pt = HISTSPACE;

	    ent = gethistent(++curhist);
	    pt = buf;
	    if (*pt == ':') {
		pt++;
		ent->stim = atol(pt);
		for (; *pt != ':' && *pt; pt++);
		if (*pt) {
		    pt++;
		    ent->ftim = atol(pt);
		    for (; *pt != ';' && *pt; pt++);
		    if (*pt)
			pt++;
		} else {
		    ent->ftim = tim;
		}
		if (ent->stim == 0)
		    ent->stim = tim;
		if (ent->ftim == 0)
		    ent->ftim = tim;
	    } else {
		ent->ftim = ent->stim = tim;
	    }
	    zsfree(ent->lex);
	    zsfree(ent->lit);
	    ent->lex = ztrdup(pt);
	    ent->lit = ztrdup(pt);
	    ent->flags = HIST_OLD;
	}
	fclose(in);
    } else if (err)
	zerr("can't read history file", s, 0);
}

void savehistfile(s, err, app)	/**/
char *s;
int err;
int app;
{
    char *t;
    FILE *out;
    int ev;
    Histent ent;

    if (!s || !interact || savehist == 0)
	return;
    ev = curhist - savehist + 1;
    if (ev < firsthist())
	ev = firsthist();
    if (app & 1)
	out = fdopen(open(s, O_CREAT | O_WRONLY | O_APPEND, 0600), "a");
    else
	out = fdopen(open(s, O_CREAT | O_WRONLY | O_TRUNC, 0600), "w");
    if (out) {
	for (; ev <= curhist; ev++) {
	    ent = gethistent(ev);
	    if (app & 2) {
		if (ent->flags & HIST_OLD)
		    continue;
		ent->flags |= HIST_OLD;
	    }
	    t = ((lithist) ? ent->lit : ent->lex);
	    if (isset(EXTENDEDHISTORY)) {
		fprintf(out, ": %ld:%ld;",
			(long)ent->stim,
			(long)ent->ftim);
	    } else if (*t == ':')
		fputc('\\', out);

	    for (; *t; t++)
		if (*t == HISTSPACE)
		    fputc(' ', out);
		else {
		    if (*t == '\n')
			fputc('\\', out);
		    fputc(*t, out);
		}
	    fputc('\n', out);
	}
	fclose(out);

	if (app & 2 && (out = fopen(s, "r"))) {
	    char **store, buf[1024], **ptr;
	    int i, l, histnum = 0;

	    store = (char **)zcalloc((savehist + 1) * sizeof *store);
	    while (fgets(buf, sizeof(buf), out)) {
		l = strlen(buf);
		if (l > 1)
		    while (l < sizeof(buf) - 1 && buf[l - 2] == '\\') {
			fgets(buf + l, sizeof buf - l, out);
			l = strlen(buf);
		    }
		if (store[i = histnum % savehist])
		    free(store[i]);
		store[i] = (char *)zalloc(l + 1);
		strcpy(store[i], buf);
		histnum++;
	    }
	    fclose(out);
	    if ((out = fdopen(open(s, O_WRONLY | O_TRUNC, 0600), "w"))) {
		if (histnum < savehist)
		    for (i = 0; i < histnum; i++)
			fprintf(out, "%s", store[i]);
		else
		    for (i = histnum; i < histnum + savehist; i++)
			fprintf(out, "%s", store[i % savehist]);
		fclose(out);
	    }
	    for (ptr = store; *ptr; ptr++)
		zsfree(*ptr);
	    free(store);
	}
    } else if (err)
	zerr("can't write history file %s", s, 0);
}

int firsthist()
{				/**/
    int ev;
    Histent ent;

    ev = curhist - histentct + 1;
    if (ev < 1)
	ev = 1;
    do {
	ent = gethistent(ev);
	if ((lithist) ? ent->lit : ent->lex)
	    break;
	ev++;
    }
    while (ev < curhist);
    return ev;
}