Initial revision

1 files changed, 1670 insertions, 0 deletions

diff --git a/Src/hist.c b/Src/hist.c
new file mode 100644
index 000000000..a4c5735c1
--- /dev/null
+++ b/Src/hist.c
@@ -0,0 +1,1670 @@
+/*
+ * hist.c - history expansion
+ *
+ * This file is part of zsh, the Z shell.
+ *
+ * Copyright (c) 1992-1997 Paul Falstad
+ * All rights reserved.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and to distribute modified versions of this software for any
+ * purpose, provided that the above copyright notice and the following
+ * two paragraphs appear in all copies of this software.
+ *
+ * In no event shall Paul Falstad or the Zsh Development Group be liable
+ * to any party for direct, indirect, special, incidental, or consequential
+ * damages arising out of the use of this software and its documentation,
+ * even if Paul Falstad and the Zsh Development Group have been advised of
+ * the possibility of such damage.
+ *
+ * Paul Falstad and the Zsh Development Group specifically disclaim any
+ * warranties, including, but not limited to, the implied warranties of
+ * merchantability and fitness for a particular purpose.  The software
+ * provided hereunder is on an "as is" basis, and Paul Falstad and the
+ * Zsh Development Group have no obligation to provide maintenance,
+ * support, updates, enhancements, or modifications.
+ *
+ */
+
+#include "zsh.mdh"
+#include "hist.pro"
+
+/* != 0 means history substitution is turned off */
+ 
+/**/
+int stophist;
+ 
+/* this line began with a space, so junk it if HISTIGNORESPACE is on */
+ 
+/**/
+int spaceflag;
+ 
+/* if != 0, we are expanding the current line */
+
+/**/
+int expanding;
+
+/* these are used to modify the cursor position during expansion */
+
+/**/
+int excs, exlast;
+
+/*
+ * Current history event number
+ *
+ * Note on curhist: with history inactive, this points to the
+ * last line actually added to the history list.  With history active,
+ * the line does not get added to the list until hend(), if at all.
+ * However, curhist is incremented to reflect the current line anyway.
+ * Thus if the line is not added to the list, curhist must be
+ * decremented in hend().
+ */
+ 
+/**/
+int curhist;
+
+/* number of history entries */
+ 
+/**/
+int histentct;
+ 
+/* array of history entries */
+ 
+/**/
+Histent histentarr;
+ 
+/* capacity of history lists */
+ 
+/**/
+int histsiz;
+ 
+/* if = 1, we have performed history substitution on the current line *
+ * if = 2, we have used the 'p' modifier                              */
+ 
+/**/
+int histdone;
+ 
+/* state of the history mechanism */
+ 
+/**/
+int histactive;
+
+/* Bits of histactive variable */
+#define HA_ACTIVE	(1<<0)	/* History mechanism is active */
+#define HA_NOSTORE	(1<<1)	/* Don't store the line when finished */
+#define HA_JUNKED	(1<<2)	/* Last history line was already junked */
+#define HA_NOINC	(1<<3)	/* Don't store, curhist not incremented */
+
+/* Array of word beginnings and endings in current history line. */
+
+/**/
+short *chwords;
+
+/* Max, actual position in chwords.
+ * nwords = chwordpos/2 because we record beginning and end of words.
+ */
+
+/**/
+int chwordlen, chwordpos;
+
+/* the last l for s/l/r/ history substitution */
+ 
+/**/
+char *hsubl;
+
+/* the last r for s/l/r/ history substitution */
+ 
+/**/
+char *hsubr;
+ 
+/* pointer into the history line */
+ 
+/**/
+char *hptr;
+ 
+/* the current history line */
+ 
+/**/
+char *chline;
+
+/* true if the last character returned by hgetc was an escaped bangchar *
+ * if it is set and NOBANGHIST is unset hwaddc escapes bangchars        */
+
+/**/
+int qbang;
+ 
+/* max size of histline */
+ 
+/**/
+int hlinesz;
+ 
+/* default event (usually curhist-1, that is, "!!") */
+ 
+static int defev;
+ 
+/* add a character to the current history word */
+
+/**/
+void
+hwaddc(int c)
+{
+    /* Only if history line exists and lexing has not finished. */
+    if (chline && !(errflag || lexstop)) {
+	/* Quote un-expanded bangs in the history line. */
+	if (c == bangchar && stophist < 2 && qbang)
+	    /* If qbang is not set, we do not escape this bangchar as it's *
+	     * not mecessary (e.g. it's a bang in !=, or it is followed    *
+	     * by a space). Roughly speaking, qbang is zero only if the    *
+	     * history interpreter has already digested this bang and      *
+	     * found that it is not necessary to escape it.                */
+	    hwaddc('\\');
+	*hptr++ = c;
+
+	/* Resize history line if necessary */
+	if (hptr - chline >= hlinesz) {
+	    int oldsiz = hlinesz;
+
+	    chline = realloc(chline, hlinesz = oldsiz + 16);
+	    hptr = chline + oldsiz;
+	}
+    }
+}
+
+/* This function adds a character to the zle input line. It is used when *
+ * zsh expands history (see doexpandhist() in zle_tricky.c). It also     *
+ * calculates the new cursor position after the expansion. It is called  *
+ * from hgetc() and from gettok() in lex.c for characters in comments.   */
+ 
+/**/
+void
+addtoline(int c)
+{
+    if (! expanding || lexstop)
+	return;
+    if (qbang && c == bangchar && stophist < 2) {
+	exlast--;
+	spaceinline(1);
+	line[cs++] = '\\';
+    }
+    if (excs > cs) {
+	excs += 1 + inbufct - exlast;
+	if (excs < cs)
+	    /* this case could be handled better but it is    *
+	     * so rare that it does not worth it              */
+	    excs = cs;
+    }
+    exlast = inbufct;
+    spaceinline(1);
+    line[cs++] = itok(c) ? ztokens[c - Pound] : c;
+}
+
+/**/
+int
+hgetc(void)
+{
+    int c = ingetc();
+
+    qbang = 0;
+    if (!stophist && !(inbufflags & INP_ALIAS)) {
+	/* If necessary, expand history characters. */
+	c = histsubchar(c);
+	if (c < 0) {
+	    /* bad expansion */
+	    errflag = lexstop = 1;
+	    return ' ';
+	}
+    }
+    if ((inbufflags & INP_HIST) && !stophist) {
+	/* the current character c came from a history expansion          *
+	 * (inbufflags && INP_HIST) and history is not disabled           *
+	 * (e.g. we are not inside single quotes). In that case, \!       *
+	 * should be treated as ! (since this \! came from a previous     *
+	 * history line where \ was used to escape the bang). So if       *
+	 * c == '\\' we fetch one more character to see if it's a bang,   *
+	 * and if it is not, we unget it and reset c back to '\\'         */
+	qbang = 0;
+	if (c == '\\' && !(qbang = (c = ingetc()) == bangchar))
+	    safeinungetc(c), c = '\\';
+    } else if (stophist || (inbufflags & INP_ALIAS))
+	/* If the result is a bangchar which came from history or alias  *
+	 * expansion, we treat it as an escaped bangchar, unless history *
+	 * is disabled. If stophist == 1 it only means that history is   *
+	 * temporarily disabled by a !" which won't appear in in the     *
+	 * history, so we still have an escaped bang. stophist > 1 if    *
+	 * history is disabled with NOBANGHIST or by someone else (e.g.  *
+	 * when the lexer scans single quoted text).                     */
+	qbang = c == bangchar && (stophist < 2);
+    hwaddc(c);
+    addtoline(c);
+
+    return c;
+}
+
+/**/
+static void
+safeinungetc(int c)
+{
+    if (lexstop)
+	lexstop = 0;
+    else
+	inungetc(c);
+}
+
+/**/
+void
+herrflush(void)
+{
+    while (!lexstop && inbufct)
+	hwaddc(ingetc());
+}
+
+/* extract :s/foo/bar/ delimiters and arguments */
+
+/**/
+static int
+getsubsargs(char *subline)
+{
+    int del;
+    char *ptr1, *ptr2;
+
+    del = ingetc();
+    ptr1 = hdynread2(del);
+    if (!ptr1)
+	return 1;
+    ptr2 = hdynread2(del);
+    if (strlen(ptr1)) {
+	zsfree(hsubl);
+	hsubl = ptr1;
+    }
+    zsfree(hsubr);
+    hsubr = ptr2;
+    if (hsubl && !strstr(subline, hsubl)) {
+	herrflush();
+	zerr("substitution failed", NULL, 0);
+	return 1;
+    }
+    return 0;
+}
+
+/* Get the maximum no. of words for a history entry. */
+
+/**/
+static int
+getargc(Histent ehist)
+{
+    return ehist->nwords ? ehist->nwords-1 : 0;
+}
+
+/* Perform history substitution, returning the next character afterwards. */
+
+/**/
+static int
+histsubchar(int c)
+{
+    int ev, farg, evset = -1, larg, argc, cflag = 0, bflag = 0;
+    static int mev = -1, marg = -1;
+    char buf[256], *ptr;
+    char *sline;
+    Histent ehist;
+
+    /* look, no goto's */
+    if (isfirstch && c == hatchar) {
+	/* Line begins ^foo^bar */
+	isfirstch = 0;
+	inungetc(hatchar);
+	if (!(ehist = gethist(defev))
+	    || !(sline = getargs(ehist, 0, getargc(ehist)))
+	    || getsubsargs(sline) || !hsubl)
+	    return -1;
+	subst(&sline, hsubl, hsubr, 0);
+    } else {
+	/* Line doesn't begin ^foo^bar */
+	if (c != ' ')
+	    isfirstch = 0;
+	if (c == '\\') {
+	    int g = ingetc();
+
+	    if (g != bangchar)
+		safeinungetc(g);
+	    else {
+		qbang = 1;
+		return bangchar;
+	    }
+	}
+	if (c != bangchar)
+	    return c;
+	*hptr = '\0';
+	if ((c = ingetc()) == '{') {
+	    bflag = cflag = 1;
+	    c = ingetc();
+	}
+	if (c == '\"') {
+	    stophist = 1;
+	    return ingetc();
+	}
+	if ((!cflag && inblank(c)) || c == '=' || c == '(' || lexstop) {
+	    safeinungetc(c);
+	    return bangchar;
+	}
+	cflag = 0;
+	ptr = buf;
+
+	/* get event number */
+
+	if (c == '?') {
+	    for (;;) {
+		c = ingetc();
+		if (c == '?' || c == '\n' || lexstop)
+		    break;
+		else
+		    *ptr++ = c;
+	    }
+	    if (c != '\n' && !lexstop)
+		c = ingetc();
+	    *ptr = '\0';
+	    mev = ev = hconsearch(hsubl = ztrdup(buf), &marg);
+	    evset = 0;
+	    if (ev == -1) {
+		herrflush();
+		zerr("no such event: %s", buf, 0);
+		return -1;
+	    }
+	} 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 = ingetc();
+		    break;
+		}
+		c = ingetc();
+	    }
+	    *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) {
+		herrflush();
+		zerr("event not found: %s", buf, 0);
+		return -1;
+	    } else
+		evset = 1;
+	}
+
+	/* get the event */
+
+	if (!(ehist = gethist(defev = ev)))
+	    return -1;
+
+	/* extract the relevant arguments */
+
+	argc = getargc(ehist);
+	if (c == ':') {
+	    cflag = 1;
+	    c = ingetc();
+	    if (c == '%' && marg != -1) {
+		if (!evset) {
+		    ehist = gethist(defev = mev);
+		    argc = getargc(ehist);
+		} else {
+		    herrflush();
+		    zerr("Ambiguous history reference", NULL, 0);
+		    return -1;
+		}
+
+	    }
+	}
+	if (c == '*') {
+	    farg = 1;
+	    larg = argc;
+	    cflag = 0;
+	} else {
+	    inungetc(c);
+	    larg = farg = getargspec(argc, marg, evset);
+	    if (larg == -2)
+		return -1;
+	    if (farg != -1)
+		cflag = 0;
+	    c = ingetc();
+	    if (c == '*') {
+		cflag = 0;
+		larg = argc;
+	    } else if (c == '-') {
+		cflag = 0;
+		larg = getargspec(argc, marg, evset);
+		if (larg == -2)
+		    return -1;
+		if (larg == -1)
+		    larg = argc - 1;
+	    } else
+		inungetc(c);
+	}
+	if (farg == -1)
+	    farg = 0;
+	if (larg == -1)
+	    larg = argc;
+	if (!(sline = getargs(ehist, farg, larg)))
+	    return -1;
+    }
+
+    /* do the modifiers */
+
+    for (;;) {
+	c = (cflag) ? ':' : ingetc();
+	cflag = 0;
+	if (c == ':') {
+	    int gbal = 0;
+
+	    if ((c = ingetc()) == 'g') {
+		gbal = 1;
+		c = ingetc();
+	    }
+	    switch (c) {
+	    case 'p':
+		histdone = HISTFLAG_DONE | HISTFLAG_NOEXEC;
+		break;
+	    case 'h':
+		if (!remtpath(&sline)) {
+		    herrflush();
+		    zerr("modifier failed: h", NULL, 0);
+		    return -1;
+		}
+		break;
+	    case 'e':
+		if (!rembutext(&sline)) {
+		    herrflush();
+		    zerr("modifier failed: e", NULL, 0);
+		    return -1;
+		}
+		break;
+	    case 'r':
+		if (!remtext(&sline)) {
+		    herrflush();
+		    zerr("modifier failed: r", NULL, 0);
+		    return -1;
+		}
+		break;
+	    case 't':
+		if (!remlpaths(&sline)) {
+		    herrflush();
+		    zerr("modifier failed: t", NULL, 0);
+		    return -1;
+		}
+		break;
+	    case 's':
+		if (getsubsargs(sline))
+		    return -1; /* fall through */
+	    case '&':
+		if (hsubl && hsubr)
+		    subst(&sline, hsubl, hsubr, gbal);
+		else {
+		    herrflush();
+		    zerr("no previous substitution", NULL, 0);
+		    return -1;
+		}
+		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);
+		return -1;
+	    }
+	} else {
+	    if (c != '}' || !bflag)
+		inungetc(c);
+	    if (c != '}' && bflag) {
+		zerr("'}' expected", NULL, 0);
+		return -1;
+	    }
+	    break;
+	}
+    }
+
+    /*
+     * Push the expanded value onto the input stack,
+     * marking this as a history word for purposes of the alias stack.
+     */
+
+    lexstop = 0;
+    /* this function is called only called from hgetc and only if      *
+     * !(inbufflags & INP_ALIAS). History expansion should never be    *
+     * done with INP_ALIAS (to prevent recursive history expansion and *
+     * histoty expansion of aliases). Escapes are not removed here.    *
+     * This is now handled in hgetc.                                   */
+    inpush(sline, INP_HIST, NULL); /* sline from heap, don't free */
+    histdone |= HISTFLAG_DONE;
+    if (isset(HISTVERIFY))
+	histdone |= HISTFLAG_NOEXEC | HISTFLAG_RECALL;
+
+    /* Don't try and re-expand line. */
+    return ingetc();
+}
+
+/* unget a char and remove it from chline. It can only be used *
+ * to unget a character returned by hgetc.                     */
+
+/**/
+void
+hungetc(int c)
+{
+    int doit = 1;
+
+    while (!lexstop) {
+	if (hptr[-1] != (char) c && stophist < 4 &&
+	    hptr > chline + 1 && hptr[-1] == '\n' && hptr[-2] == '\\')
+	    hungetc('\n'), hungetc('\\');
+
+	if (expanding) {
+	    cs--;
+	    ll--;
+	    exlast++;
+	}
+	DPUTS(hptr <= chline, "BUG: hungetc attempted at buffer start");
+	hptr--;
+	DPUTS(*hptr != (char) c, "BUG: wrong character in hungetc() ");
+	qbang = (c == bangchar && stophist < 2 &&
+		 hptr > chline && hptr[-1] == '\\');
+	if (doit)
+	    inungetc(c);
+	if (!qbang)
+	    return;
+	doit = !stophist && ((inbufflags & INP_HIST) ||
+				 !(inbufflags & INP_ALIAS));
+	c = '\\';
+    }
+}
+
+/* begin reading a string */
+
+/**/
+void
+strinbeg(void)
+{
+    strin++;
+    hbegin();
+    lexinit();
+}
+
+/* done reading a string */
+
+/**/
+void
+strinend(void)
+{
+    hend();
+    DPUTS(!strin, "BUG: strinend() called without strinbeg()");
+    strin--;
+    isfirstch = 1;
+    histdone = 0;
+}
+
+/* initialize the history mechanism */
+
+/**/
+void
+hbegin(void)
+{
+    Histent curhistent;
+
+    isfirstln = isfirstch = 1;
+    errflag = histdone = spaceflag = 0;
+    stophist = (!interact || unset(BANGHIST) || unset(SHINSTDIN)) << 1;
+    chline = hptr = zcalloc(hlinesz = 16);
+    chwords = zalloc((chwordlen = 16)*sizeof(short));
+    chwordpos = 0;
+
+    if (histactive & HA_JUNKED)
+	curhist--;
+    curhistent = gethistent(curhist);
+    if (!curhistent->ftim)
+	curhistent->ftim = time(NULL);
+    histactive = HA_ACTIVE;
+    if (interact && isset(SHINSTDIN) && !strin) {
+	attachtty(mypgrp);
+	defev = curhist;
+	curhist++;
+    } else
+	histactive |= HA_NOINC;
+}
+
+/* compare current line with history entry using only text in words */
+
+/**/
+static int
+histcmp(Histent he)
+{
+    int kword, lword;
+    int nwords = chwordpos/2;
+
+    /* If the history entry came from a file, the words were not
+     * divided by the lexer so we have to resort to strcmp.
+     */
+    if (he->flags & HIST_READ)
+	return strcmp(he->text, chline);
+
+    if (nwords != he->nwords)
+	return 1;
+
+    for (kword = 0; kword < 2*nwords; kword += 2)
+	if ((lword = chwords[kword+1]-chwords[kword])
+	    != he->words[kword+1]-he->words[kword] ||
+	    memcmp(he->text+he->words[kword], chline+chwords[kword], lword))
+	    return 1;
+
+    return 0;
+}
+
+/**/
+void
+histreduceblanks(void)
+{
+    int i, len, pos, needblank;
+
+    for (i = 0, len = 0; i < chwordpos; i += 2) {
+	len += chwords[i+1] - chwords[i]
+	     + (i > 0 && chwords[i] > chwords[i-1]);
+    }
+    if (chline[len] == '\0')
+	return;
+
+    for (i = 0, pos = 0; i < chwordpos; i += 2) {
+	len = chwords[i+1] - chwords[i];
+	needblank = (i < chwordpos-2 && chwords[i+2] > chwords[i+1]);
+	if (pos != chwords[i]) {
+	    memcpy(chline + pos, chline + chwords[i], len + needblank);
+	    chwords[i] = pos;
+	    chwords[i+1] = chwords[i] + len;
+	}
+	pos += len + needblank;
+    }
+    chline[pos] = '\0';
+}
+
+/* say we're done using the history mechanism */
+
+/**/
+int
+hend(void)
+{
+    int flag, save = 1;
+
+    DPUTS(!chline, "BUG: chline is NULL in hend()");
+    if (histactive & (HA_NOSTORE|HA_NOINC)) {
+	zfree(chline, hlinesz);
+	zfree(chwords, chwordlen*sizeof(short));
+	chline = NULL;
+	if (!(histactive & HA_NOINC))
+	    curhist--;
+	histactive = 0;
+	return 1;
+    }
+    flag = histdone;
+    histdone = 0;
+    if (hptr < chline + 1)
+	save = 0;
+    else {
+	*hptr = '\0';
+	if (hptr[-1] == '\n')
+	    if (chline[1]) {
+		*--hptr = '\0';
+	    } else
+		save = 0;
+	if (!*chline || !strcmp(chline, "\n") ||
+	    (isset(HISTIGNORESPACE) && spaceflag))
+	    save = 0;
+    }
+    if (flag & (HISTFLAG_DONE | HISTFLAG_RECALL)) {
+	char *ptr;
+
+	ptr = ztrdup(chline);
+	if ((flag & (HISTFLAG_DONE | HISTFLAG_RECALL)) == HISTFLAG_DONE) {
+	    zputs(ptr, shout);
+	    fputc('\n', shout);
+	    fflush(shout);
+	}
+	if (flag & HISTFLAG_RECALL) {
+	    PERMALLOC {
+		pushnode(bufstack, ptr);
+	    } LASTALLOC;
+	    save = 0;
+	} else
+	    zsfree(ptr);
+    }
+    if (save) {
+	Histent he;
+	int keepflags = 0;
+
+#ifdef DEBUG
+	/* debugging only */
+	if (chwordpos%2) {
+	    hwend();
+	    DPUTS(1, "BUG: uncompleted line in history");
+	}
+#endif
+	/* get rid of pesky \n which we've already nulled out */
+	if (!chline[chwords[chwordpos-2]])
+	    chwordpos -= 2;
+	/* strip superfluous blanks, if desired */
+	if (isset(HISTREDUCEBLANKS))
+	    histreduceblanks();
+
+	if (isset(HISTIGNOREDUPS) && (he = gethistent(curhist - 1))
+	 && he->text && !histcmp(he)) {
+	    /* This history entry compares the same as the previous.
+	     * In case minor changes were made, we overwrite the
+	     * previous one with the current one.  This also gets
+	     * the timestamp right.  However, keep the old flags.
+	     */
+	    keepflags = he->flags;
+	    curhist--;
+	}
+
+	he =  gethistent(curhist);
+	zsfree(he->text);
+	he->text = ztrdup(chline);
+	if (he->nwords)
+	    zfree(he->words, he->nwords*2*sizeof(short));
+	he->stim = time(NULL);
+	he->ftim = 0L;
+	he->flags = keepflags;
+
+	if ((he->nwords = chwordpos/2)) {
+	    he->words = (short *)zalloc(chwordpos * sizeof(short));
+	    memcpy(he->words, chwords, chwordpos * sizeof(short));
+	}
+    } else
+	curhist--;
+    zfree(chline, hlinesz);
+    zfree(chwords, chwordlen*sizeof(short));
+    chline = NULL;
+    histactive = 0;
+    return !(flag & HISTFLAG_NOEXEC || errflag);
+}
+
+/* remove the current line from the history List */
+
+/**/
+void
+remhist(void)
+{
+    if (!(histactive & HA_ACTIVE)) {
+	if (!(histactive & HA_JUNKED)) {
+	    /* make sure this doesn't show up when we do firsthist() */
+	    Histent he = gethistent(curhist);
+	    zsfree(he->text);
+	    he->text = NULL;
+	    histactive |= HA_JUNKED;
+	    /* curhist-- is delayed until the next hbegin() */
+	}
+    } else
+	histactive |= HA_NOSTORE;
+}
+
+/* Gives current expansion word if not last word before chwordpos. */
+
+/**/
+int hwgetword = -1;
+
+/* begin a word */
+
+/**/
+void
+hwbegin(int offset)
+{
+    if (chwordpos%2)
+	chwordpos--;	/* make sure we're on a word start, not end */
+    /* If we're expanding an alias, we should overwrite the expansion
+     * in the history.
+     */
+    if ((inbufflags & INP_ALIAS) && !(inbufflags & INP_HIST))
+	hwgetword = chwordpos;
+    else
+	hwgetword = -1;
+    chwords[chwordpos++] = hptr - chline + offset;
+}
+
+/* add a word to the history List */
+
+/**/
+void
+hwend(void)
+{
+    if (chwordpos%2 && chline) {
+	/* end of word reached and we've already begun a word */
+	if (hptr > chline + chwords[chwordpos-1]) {
+	    chwords[chwordpos++] = hptr - chline;
+	    if (chwordpos >= chwordlen) {
+		chwords = (short *) realloc(chwords,
+					    (chwordlen += 16)*sizeof(short));
+	    }
+	    if (hwgetword > -1) {
+		/* We want to reuse the current word position */
+		chwordpos = hwgetword;
+		/* Start from where previous word ended, if possible */
+		hptr = chline + chwords[chwordpos ? chwordpos - 1 : 0];
+	    }
+	} else {
+	    /* scrub that last word, it doesn't exist */
+	    chwordpos--;
+	}
+    }
+}
+
+/* Go back to immediately after the last word, skipping space. */
+
+/**/
+void
+histbackword(void)
+{
+    if (!(chwordpos%2) && chwordpos)
+	hptr = chline + chwords[chwordpos-1];
+}
+
+/* Get the start and end point of the current history word */
+
+/**/
+static void
+hwget(char **startptr)
+{
+    int pos = hwgetword > -1 ? hwgetword : chwordpos - 2;
+
+#ifdef DEBUG
+    /* debugging only */
+    if (hwgetword == -1 && !chwordpos) {
+	/* no words available */
+	DPUTS(1, "BUG: hwget() called with no words");
+	*startptr = "";
+	return;
+    } 
+    else if (hwgetword == -1 && chwordpos%2) {
+	DPUTS(1, "BUG: hwget() called in middle of word");
+	*startptr = "";
+	return;
+    }
+#endif
+
+    *startptr = chline + chwords[pos];
+    chline[chwords[++pos]] = '\0';
+}
+
+/* Replace the current history word with rep, if different */
+
+/**/
+void
+hwrep(char *rep)
+{
+    char *start;
+    hwget(&start);
+
+    if (!strcmp(rep, start))
+	return;
+    
+    hptr = start;
+    chwordpos = (hwgetword > -1) ? hwgetword : chwordpos - 2;
+    hwbegin(0);
+    qbang = 1;
+    while (*rep)
+	hwaddc(*rep++);
+    hwend();
+}
+
+/* Get the entire current line, deleting it in the history. */
+
+/**/
+char *
+hgetline(void)
+{
+    /* Currently only used by pushlineoredit().
+     * It's necessary to prevent that from getting too pally with
+     * the history code.
+     */
+    char *ret;
+
+    if (!chline || hptr == chline)
+	return NULL;
+    *hptr = '\0';
+    ret = dupstring(chline);
+
+    /* reset line */
+    hptr = chline;
+    chwordpos = 0;
+    hwgetword = -1;
+
+    return ret;
+}
+
+/* get an argument specification */
+
+/**/
+static int
+getargspec(int argc, int marg, int evset)
+{
+    int c, ret = -1;
+
+    if ((c = ingetc()) == '0')
+	return 0;
+    if (idigit(c)) {
+	ret = 0;
+	while (idigit(c)) {
+	    ret = ret * 10 + c - '0';
+	    c = ingetc();
+	}
+	inungetc(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
+	inungetc(c);
+    return ret;
+}
+
+/* do ?foo? search */
+
+/**/
+static int
+hconsearch(char *str, int *marg)
+{
+    int t0, t1 = 0;
+    char *s;
+    Histent he;
+
+    for (t0 = curhist - 1; (he = quietgethist(t0)); t0--)
+	if ((s = strstr(he->text, str))) {
+	    int pos = s - he->text;
+	    while (t1 < he->nwords && he->words[2*t1] <= pos)
+		t1++;
+	    *marg = t1 - 1;
+	    return t0;
+	}
+    return -1;
+}
+
+/* do !foo search */
+
+/**/
+int
+hcomsearch(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(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(char **junkptr)
+{
+    char *str = *junkptr, *remcut;
+
+    if ((remcut = strrchr(str, '.')) && remcut != str) {
+	*remcut = '\0';
+	return 1;
+    }
+    return 0;
+}
+
+/**/
+int
+rembutext(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(char **junkptr)
+{
+    char *str = *junkptr, *remcut;
+
+    if ((remcut = strrchr(str, '/'))) {
+	*remcut = '\0';
+	*junkptr = dupstring(remcut + 1);
+	return 1;
+    }
+    return 0;
+}
+
+/**/
+int
+makeuppercase(char **junkptr)
+{
+    char *str = *junkptr;
+
+    for (; *str; str++)
+	*str = tuupper(*str);
+    return 1;
+}
+
+/**/
+int
+makelowercase(char **junkptr)
+{
+    char *str = *junkptr;
+
+    for (; *str; str++)
+	*str = tulower(*str);
+    return 1;
+}
+
+/**/
+int
+makecapitals(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(char **strptr, char *in, char *out, int gbal)
+{
+    char *str = *strptr, *instr = *strptr, *substcut, *sptr, *oldstr;
+    int off, inlen, outlen;
+
+    if (!*in)
+	in = str, gbal = 0;
+    if (!(substcut = (char *)strstr(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 *)strstr(str, in)));
+}
+
+/**/
+static char *
+convamps(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;
+}
+
+/**/
+struct histent *
+quietgethist(int ev)
+{
+    static struct histent storehist;
+
+    if (ev < firsthist() || ev > curhist)
+	return NULL;
+    if (ev == curhist && (histactive & HA_ACTIVE)) {
+	/* The current history line has not been stored.  Build it up
+	 * from other variables.
+	 */
+	storehist.text = chline;
+	storehist.nwords = chwordpos/2;
+	storehist.words = chwords;
+
+	return &storehist;
+    } else
+	return gethistent(ev);
+}
+
+/**/
+char *
+quietgetevent(int ev)
+{
+    Histent ent = quietgethist(ev);
+
+    return ent ? ent->text : NULL;
+}
+
+/**/
+static Histent
+gethist(int ev)
+{
+    Histent ret;
+
+    ret = quietgethist(ev);
+    if (!ret) {
+	herrflush();
+	zerr("no such event: %d", NULL, ev);
+    }
+    return ret;
+}
+
+/**/
+static char *
+getargs(Histent elist, int arg1, int arg2)
+{
+    short *words = elist->words;
+    int pos1, nwords = elist->nwords;
+
+    if (arg2 < arg1 || arg1 >= nwords || arg2 >= nwords) {
+	/* remember, argN is indexed from 0, nwords is total no. of words */
+	herrflush();
+	zerr("no such word in event", NULL, 0);
+	return NULL;
+    }
+
+    pos1 = words[2*arg1];
+    return dupstrpfx(elist->text + pos1, words[2*arg2+1] - pos1);
+}
+
+/**/
+void
+upcase(char **x)
+{
+    char *pp = *(char **)x;
+
+    for (; *pp; pp++)
+	*pp = tuupper(*pp);
+}
+
+/**/
+void
+downcase(char **x)
+{
+    char *pp = *(char **)x;
+
+    for (; *pp; pp++)
+	*pp = tulower(*pp);
+}
+
+/**/
+int
+quote(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;
+}
+
+/**/
+static int
+quotebreak(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;
+}
+
+#if 0
+/* read an arbitrary amount of data into a buffer until stop is found */
+
+/**/
+char *
+hdynread(int stop)
+{
+    int bsiz = 256, ct = 0, c;
+    char *buf = (char *)zalloc(bsiz), *ptr;
+
+    ptr = buf;
+    while ((c = ingetc()) != stop && c != '\n' && !lexstop) {
+	if (c == '\\')
+	    c = ingetc();
+	*ptr++ = c;
+	if (++ct == bsiz) {
+	    buf = realloc(buf, bsiz *= 2);
+	    ptr = buf + ct;
+	}
+    }
+    *ptr = 0;
+    if (c == '\n') {
+	inungetc('\n');
+	zerr("delimiter expected", NULL, 0);
+	zfree(buf, bsiz);
+	return NULL;
+    }
+    return buf;
+}
+#endif
+
+/**/
+static char *
+hdynread2(int stop)
+{
+    int bsiz = 256, ct = 0, c;
+    char *buf = (char *)zalloc(bsiz), *ptr;
+
+    ptr = buf;
+    while ((c = ingetc()) != stop && c != '\n' && !lexstop) {
+	if (c == '\n') {
+	    inungetc(c);
+	    break;
+	}
+	if (c == '\\')
+	    c = ingetc();
+	*ptr++ = c;
+	if (++ct == bsiz) {
+	    buf = realloc(buf, bsiz *= 2);
+	    ptr = buf + ct;
+	}
+    }
+    *ptr = 0;
+    if (c == '\n')
+	inungetc('\n');
+    return buf;
+}
+
+/**/
+void
+inithist(void)
+{
+    histentct = histsiz;
+    histentarr = (Histent) zcalloc(histentct * sizeof *histentarr);
+}
+
+/**/
+void
+resizehistents(void)
+{
+    int newentct, t0, t1, firstlex;
+    Histent newarr;
+
+    newentct = histsiz;
+    newarr = (Histent) zcalloc(newentct * sizeof *newarr);
+    firstlex = curhist - histsiz + 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].text);
+	    newarr[t1].text = NULL;
+	}
+	t1++;
+	if (t1 == newentct)
+	    t1 = 0;
+    }
+    free(histentarr);
+    histentarr = newarr;
+    histentct = newentct;
+}
+
+/**/
+void
+readhistfile(char *s, int err)
+{
+    char *buf;
+    FILE *in;
+    Histent ent;
+    time_t tim = time(NULL);
+    short *wordlist;
+    int nwordpos, nwordlist, bufsiz;
+
+    if (!s)
+	return;
+    if ((in = fopen(unmeta(s), "r"))) {
+	nwordlist = 16;
+	wordlist = (short *)zalloc(nwordlist*sizeof(short));
+	bufsiz = 1024;
+	buf = zalloc(bufsiz);
+
+	while (fgets(buf, bufsiz, in)) {
+	    int l = strlen(buf);
+	    char *pt, *start;
+
+	    while (l) {
+		while (buf[l - 1] != '\n') {
+		    buf = zrealloc(buf, 2 * bufsiz);
+		    bufsiz = 2 * bufsiz;
+		    if (!fgets(buf + l, bufsiz - l, in)) {
+			l++;
+			break;
+		    }
+		    l = strlen(buf);
+		}
+		buf[l - 1] = '\0';
+		if (l > 1 && buf[l - 2] == '\\') {
+		    buf[l - 2] = '\n';
+		    fgets(buf + l - 1, bufsiz - (l - 1), in);
+		    l = strlen(buf);
+		} else
+		    break;
+	    }
+
+	    ent = gethistent(++curhist);
+	    pt = buf;
+	    if (*pt == ':') {
+		pt++;
+		ent->stim = zstrtol(pt, NULL, 0);
+		for (; *pt != ':' && *pt; pt++);
+		if (*pt) {
+		    pt++;
+		    ent->ftim = zstrtol(pt, NULL, 0);
+		    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->text);
+	    ent->text = ztrdup(pt);
+	    ent->flags = HIST_OLD|HIST_READ;
+	    if (ent->nwords)
+		zfree(ent->words, ent->nwords*2*sizeof(short));
+
+	    /* Divide up the words.  We don't know how it lexes,
+	       so just look for spaces.
+	       */
+	    nwordpos = 0;
+	    start = pt;
+	    do {
+		while (*pt == ' ')
+		    pt++;
+		if (*pt) {
+		    if (nwordpos >= nwordlist)
+			wordlist = (short *) realloc(wordlist,
+					(nwordlist += 16)*sizeof(short));
+		    wordlist[nwordpos++] = pt - start;
+		    while (*pt && *pt != ' ')
+			pt++;
+		    wordlist[nwordpos++] = pt - start;
+		}
+	    } while (*pt);
+
+	    ent->nwords = nwordpos/2;
+	    if (ent->nwords) {
+		ent->words = (short *)zalloc(nwordpos*sizeof(short));
+		memcpy(ent->words, wordlist, nwordpos*sizeof(short));
+	    } else
+		ent->words = (short *)NULL;
+	}
+	fclose(in);
+
+	zfree(wordlist, nwordlist*sizeof(short));
+	zfree(buf, bufsiz);
+    } else if (err)
+	zerr("can't read history file", s, 0);
+}
+
+/**/
+void
+savehistfile(char *s, int err, int app)
+{
+    char *t;
+    FILE *out;
+    int ev;
+    Histent ent;
+    int savehist = getiparam("SAVEHIST");
+
+    if (!s || !interact || savehist <= 0)
+	return;
+    ev = curhist - savehist + 1;
+    if (ev < firsthist())
+	ev = firsthist();
+    if (app & 1)
+	out = fdopen(open(unmeta(s),
+		     O_CREAT | O_WRONLY | O_APPEND | O_NOCTTY, 0600), "a");
+    else
+	out = fdopen(open(unmeta(s),
+		     O_CREAT | O_WRONLY | O_TRUNC | O_NOCTTY, 0600), "w");
+    if (out) {
+	for (; ev <= curhist - !!(histactive & HA_ACTIVE); ev++) {
+	    ent = gethistent(ev);
+	    if (app & 2) {
+		if (ent->flags & HIST_OLD)
+		    continue;
+		ent->flags |= HIST_OLD;
+	    }
+	    t = ent->text;
+	    if (isset(EXTENDEDHISTORY)) {
+		fprintf(out, ": %ld:%ld;",
+			(long)ent->stim,
+			(long)ent->ftim);
+	    } else if (*t == ':')
+		fputc('\\', out);
+
+	    for (; *t; t++) {
+		if (*t == '\n')
+		    fputc('\\', out);
+		fputc(*t, out);
+	    }
+	    fputc('\n', out);
+	}
+	fclose(out);
+
+	if (app & 2 && (out = fopen(unmeta(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)) {
+		char *t;
+
+		if (store[i = histnum % savehist])
+		    free(store[i]);
+		store[i] = ztrdup(buf);
+		l = strlen(buf);
+		if (l > 1) {
+		    t = store[i] + l;
+		    while ((t[-1] != '\n' ||
+			    (t[-1] == '\n' && t[-2] == '\\')) &&
+			   fgets(buf, sizeof(buf), out)) {
+			l += strlen(buf);
+			store[i] = zrealloc(store[i], l + 1);
+			t = store[i] + l;
+			strcat(store[i], buf);
+		    }
+		}
+		histnum++;
+	    }
+	    fclose(out);
+	    if ((out = fdopen(open(unmeta(s),
+			    O_WRONLY | O_TRUNC | O_NOCTTY, 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(void)
+{
+    int ev;
+    Histent ent;
+
+    ev = curhist - histentct + 1;
+    if (ev < 1)
+	ev = 1;
+    do {
+	ent = gethistent(ev);
+	if (ent->text)
+	    break;
+	ev++;
+    }
+    while (ev < curhist);
+    return ev;
+}
+