2BSD/src/csh/sh.lex.c
/* Copyright (c) 1979 Regents of the University of California */
#include "sh.h"
/*
* C shell
*/
/*
* These lexical routines read input and form lists of words.
* There is some involved processing here, because of the complications
* of input buffering, and especially because of history substitution.
*/
char *word();
/*
* Peekc is a peek characer for getC, peekread for readc.
* There is a subtlety here in many places... history routines
* will read ahead and then insert stuff into the input stream.
* If they push back a character then they must push it behind
* the text substituted by the history substitution. On the other
* hand in several places we need 2 peek characters. To make this
* all work, the history routines read with getC, and make use both
* of ungetC and unreadc. The key observation is that the state
* of getC at the call of a history reference is such that calls
* to getC from the history routines will always yield calls of
* readc, unless this peeking is involved. That is to say that during
* getexcl the variables lap, exclp, and exclnxt are all zero.
*
* Getdol invokes history substitution, hence the extra peek, peekd,
* which it can ungetD to be before history substitutions.
*/
char peekc, peekd;
char peekread;
char *exclp; /* (Tail of) current word from ! subst */
struct wordent *exclnxt; /* The rest of the ! subst words */
int exclc; /* Count of remainig words in ! subst */
char *alvecp; /* "Globp" for alias resubstitution */
/*
* Lex returns to its caller not only a wordlist (as a "var" parameter)
* but also whether a history substitution occurred. This is used in
* the main (process) routine to determine whether to echo, and also
* when called by the alias routine to determine whether to keep the
* argument list.
*/
bool hadhist;
#define ungetC(c) peekc = c
#define ungetD(c) peekd = c
lex(hp)
register struct wordent *hp;
{
register struct wordent *wdp;
int c;
lineloc = btell();
hp->next = hp->prev = hp;
hp->word = "";
alvecp = 0, hadhist = 0;
do
c = readc(0);
while (c == ' ' || c == '\t');
if (c == '^' && intty)
/* ^lef^rit from tty is short !:s^lef^rit */
getexcl(c);
else
unreadc(c);
wdp = hp;
/*
* The following loop is written so that the links needed
* by freelex will be ready and rarin to go even if it is
* interrupted.
*/
do {
register struct wordent *new = (struct wordent *) calloc(1, sizeof *wdp);
new->prev = wdp;
new->next = hp;
wdp->next = new;
wdp = new;
wdp->word = word();
} while (wdp->word[0] != '\n');
hp->prev = wdp;
return (hadhist);
}
prlex(sp0)
struct wordent *sp0;
{
register struct wordent *sp = sp0->next;
for (;;) {
printf("%s", sp->word);
sp = sp->next;
if (sp == sp0)
break;
printf(" ");
}
}
copylex(hp, fp)
register struct wordent *hp;
struct wordent *fp;
{
register struct wordent *wdp;
wdp = hp;
fp = fp->next;
do {
register struct wordent *new = (struct wordent *) calloc(1, sizeof *wdp);
new->prev = wdp;
new->next = hp;
wdp->next = new;
wdp = new;
wdp->word = savestr(fp->word);
fp = fp->next;
} while (wdp->word[0] != '\n');
hp->prev = wdp;
}
freelex(vp)
register struct wordent *vp;
{
register struct wordent *fp;
while (vp->next != vp) {
fp = vp->next;
vp->next = fp->next;
xfree(fp->word);
xfree(fp);
}
vp->prev = vp;
}
char *WORDMETA = "# '`\"\t;&<>()|\n";
char *
word()
{
register char c, c1;
register char *wp;
char wbuf[BUFSIZ];
register bool dolflg;
register int i;
wp = wbuf;
i = BUFSIZ - 4;
loop:
c = getC(DOALL);
switch (c) {
case ' ':
case '\t':
goto loop;
case '`':
case '\'':
case '"':
*wp++ = c, --i, c1 = c;
dolflg = c == '"' ? DOALL : DOEXCL;
for (;;) {
c = getC(dolflg);
if (c == c1)
break;
if (c == '\n') {
seterrc("Unmatched ", c1);
ungetC(c);
goto ret;
}
if (c == '\\') {
c = getC(0);
if (c == '!')
c |= QUOTE;
else {
if (c == '\n' && c1 != '`')
c |= QUOTE;
ungetC(c), c = '\\';
}
}
if (--i <= 0)
goto toochars;
*wp++ = c;
}
*wp++ = c, --i;
goto pack;
case '&':
case '|':
case '<':
case '>':
*wp++ = c;
c1 = getC(DOALL);
if (c1 == c)
*wp++ = c1;
else
ungetC(c1);
goto ret;
case '#':
if (intty)
break;
if (wp != wbuf) {
ungetC(c);
goto ret;
}
c = 0;
do {
c1 = c;
c = getC(0);
} while (c != '\n');
if (c1 == '\\')
goto loop;
/* fall into ... */
case ';':
case '(':
case ')':
case '\n':
*wp++ = c;
goto ret;
casebksl:
case '\\':
c = getC(0);
if (c == '\n') {
if (onelflg == 1)
onelflg = 2;
goto loop;
}
if (c != '!')
*wp++ = '\\', --i;
c |= QUOTE;
break;
}
ungetC(c);
pack:
for (;;) {
c = getC(DOALL);
if (c == '\\') {
c = getC(0);
if (c == '\n') {
if (onelflg == 1)
onelflg = 2;
goto ret;
}
if (c != '!')
*wp++ = '\\', --i;
c |= QUOTE;
}
if (any(c, WORDMETA + intty)) {
ungetC(c);
if (any(c, "\"'`"))
goto loop;
goto ret;
}
if (--i <= 0)
goto toochars;
*wp++ = c;
}
toochars:
seterr("Word too long");
wp = &wbuf[1];
ret:
*wp = 0;
return (savestr(wbuf));
}
getC(flag)
register int flag;
{
register char c;
top:
if (c = peekc) {
peekc = 0;
return (c);
}
if (lap) {
c = *lap++;
if (c == 0) {
lap = 0;
goto top;
}
if (any(c, WORDMETA + intty))
c |= QUOTE;
return (c);
}
if (c = peekd) {
peekd = 0;
return (c);
}
if (exclp) {
if (c = *exclp++)
return (c);
if (exclnxt && --exclc >= 0) {
exclnxt = exclnxt->next;
setexclp(exclnxt->word);
return (' ');
}
exclp = 0;
exclnxt = 0;
}
if (exclnxt) {
exclnxt = exclnxt->next;
if (--exclc < 0)
exclnxt = 0;
else
setexclp(exclnxt->word);
goto top;
}
c = readc(0);
if (c == '$' && (flag & DODOL)) {
getdol();
goto top;
}
if (c == '!' && (flag & DOEXCL)) {
getexcl(0);
goto top;
}
return (c);
}
getdol()
{
register char *np;
char name[40];
register int c;
int sc;
bool special = 0;
np = name, *np++ = '$';
c = sc = getC(DOEXCL);
if (any(c, "\t \n")) {
ungetD(c);
ungetC('$' | QUOTE);
return;
}
if (c == '{')
*np++ = c, c = getC(DOEXCL);
if (c == '#' || c == '?')
special++, *np++ = c, c = getC(DOEXCL);
*np++ = c;
switch (c) {
case '$':
if (special)
goto vsyn;
goto ret;
case '\n':
ungetD(c);
np--;
goto vsyn;
case '*':
if (special)
goto vsyn;
goto ret;
default:
if (digit(c)) {
/*
* let $?0 pass for now
if (special)
goto vsyn;
*/
while (digit(c = getC(DOEXCL))) {
if (np < &name[sizeof name / 2])
*np++ = c;
}
} else if (letter(c))
while (letter(c = getC(DOEXCL))) {
if (np < &name[sizeof name / 2])
*np++ = c;
}
else
goto vsyn;
}
if (c == '[') {
*np++ = c;
do {
c = getC(DOEXCL);
if (c == '\n') {
ungetD(c);
np--;
goto vsyn;
}
if (np >= &name[sizeof name - 8])
goto vsyn;
*np++ = c;
} while (c != ']');
c = getC(DOEXCL);
}
if (c == ':') {
*np++ = c, c = getC(DOEXCL);
if (c == 'g')
*np++ = c, c = getC(DOEXCL);
*np++ = c;
if (!any(c, "htrqx"))
goto vsyn;
} else
ungetD(c);
if (sc == '{') {
c = getC(DOEXCL);
if (c != '}') {
ungetC(c);
goto vsyn;
}
*np++ = c;
}
ret:
*np = 0;
addla(name);
return;
vsyn:
seterr("Variable syntax");
goto ret;
}
addla(cp)
char *cp;
{
char buf[BUFSIZ];
if (lap != 0 && strlen(cp) + strlen(lap) >= BUFSIZ - 4) {
seterr("Expansion buf ovflo");
return;
}
if (lap)
strcpy(buf, lap);
strcpy(labuf, cp);
if (lap)
strcat(labuf, buf);
lap = labuf;
}
char lhsb[32];
char slhs[32];
char rhsb[64];
int quesarg;
getexcl(sc)
char sc;
{
register struct wordent *hp, *ip;
int left, right, dol;
register int c;
if (sc == 0) {
sc = getC(0);
if (sc != '{') {
ungetC(sc);
sc = 0;
}
}
quesarg = -1;
lastev = eventno;
hp = gethent(sc);
if (hp == 0)
return;
hadhist = 1;
dol = 0;
if (hp == alhistp)
for (ip = hp->next->next; ip != alhistt; ip = ip->next)
dol++;
else
for (ip = hp->next->next; ip != hp->prev; ip = ip->next)
dol++;
left = 0, right = dol;
if (sc == '^') {
ungetC('s'), unreadc('^'), c = ':';
goto subst;
}
c = getC(0);
if (!any(c, ":^$*-%"))
goto subst;
left = right = -1;
if (c == ':') {
c = getC(0);
unreadc(c);
if (letter(c) || c == '&') {
c = ':';
left = 0, right = dol;
goto subst;
}
} else
ungetC(c);
if (!getsel(&left, &right, dol))
return;
c = getC(0);
if (c == '*')
ungetC(c), c = '-';
if (c == '-') {
if (!getsel(&left, &right, dol))
return;
c = getC(0);
}
subst:
exclc = right - left + 1;
while (--left >= 0)
hp = hp->next;
if (sc == '^' || c == ':') {
do {
hp = getsub(hp);
c = getC(0);
} while (c == ':');
}
unreadc(c);
if (sc == '{') {
c = getC(0);
if (c != '}')
seterr("Bad ! form");
}
exclnxt = hp;
}
struct wordent *
getsub(en)
struct wordent *en;
{
register char *cp;
int delim;
register int c;
int sc;
bool global = 0;
char orhsb[sizeof rhsb];
exclnxt = 0;
sc = c = getC(0);
if (c == 'g')
global++, c = getC(0);
switch (c) {
case 'p':
justpr++;
goto ret;
case 'x':
case 'q':
global++;
/* fall into ... */
case 'h':
case 'r':
case 't':
break;
case '&':
if (slhs[0] == 0) {
seterr("No prev sub");
goto ret;
}
strcpy(lhsb, slhs);
break;
/*
case '~':
if (lhsb[0] == 0)
goto badlhs;
break;
*/
case 's':
delim = getC(0);
if (letter(delim) || digit(delim) || any(delim, " \t\n")) {
unreadc(delim);
bads:
lhsb[0] = 0;
seterr("Bad substitute");
goto ret;
}
cp = lhsb;
for (;;) {
c = getC(0);
if (c == '\n') {
unreadc(c);
goto bads;
}
if (c == delim)
break;
if (cp > &lhsb[sizeof lhsb - 2])
goto bads;
if (c == '\\') {
c = getC(0);
if (c != delim && c != '\\')
*cp++ = '\\';
}
*cp++ = c;
}
if (cp != lhsb)
*cp++ = 0;
else if (lhsb[0] == 0) {
badlhs:
seterr("No prev lhs");
goto ret;
}
cp = rhsb;
strcpy(orhsb, cp);
for (;;) {
c = getC(0);
if (c == '\n') {
unreadc(c);
break;
}
if (c == delim)
break;
/*
if (c == '~') {
if (&cp[strlen(orhsb)] > &rhsb[sizeof rhsb - 2])
goto toorhs;
cp = strend(strcpy(cp, orhsb));
continue;
}
*/
if (cp > &rhsb[sizeof rhsb - 2]) {
toorhs:
seterr("Rhs too long");
goto ret;
}
if (c == '\\') {
c = getC(0);
if (c != delim /* && c != '~' */)
*cp++ = '\\';
}
*cp++ = c;
}
*cp++ = 0;
break;
default:
if (c == '\n')
unreadc(c);
seterrc("Bad ! modifier: ", c);
goto ret;
}
strcpy(slhs, lhsb);
if (exclc)
en = dosub(sc, en, global);
ret:
return (en);
}
struct wordent *
dosub(sc, en, global)
int sc;
struct wordent *en;
bool global;
{
struct wordent lex;
bool didsub = 0;
struct wordent *hp = &lex;
register struct wordent *wdp;
register int i = exclc;
wdp = hp;
while (--i >= 0) {
register struct wordent *new = (struct wordent *) calloc(1, sizeof *wdp);
new->prev = wdp;
new->next = hp;
wdp->next = new;
wdp = new;
en = en->next;
wdp->word = global || didsub == 0 ?
subword(en->word, sc, &didsub) : savestr(en->word);
}
if (didsub == 0)
seterr("Modifier failed");
hp->prev = wdp;
return (&enthist(-1000, &lex, 0)->Hlex);
}
char *
subword(cp, type, adid)
char *cp;
int type;
bool *adid;
{
char wbuf[BUFSIZ];
register char *wp, *mp, *np;
register int i;
switch (type) {
case 'r':
case 'h':
case 't':
case 'q':
case 'x':
wp = domod(cp, type);
if (wp == 0)
return (savestr(cp));
*adid = 1;
return (wp);
default:
wp = wbuf;
i = BUFSIZ - 4;
for (mp = cp; *mp; mp++)
if (matchs(mp, lhsb)) {
for (np = cp; np < mp;)
*wp++ = *np++, --i;
for (np = rhsb; *np; np++) switch (*np) {
case '\\':
if (np[1] == '&')
np++;
/* fall into ... */
default:
if (--i < 0)
goto ovflo;
*wp++ = *np;
continue;
case '&':
i -= strlen(lhsb);
if (i < 0)
goto ovflo;
*wp = 0;
strcat(wp, lhsb);
wp = strend(wp);
continue;
}
mp += strlen(lhsb);
i -= strlen(mp);
if (i < 0) {
ovflo:
seterr("Subst buf ovflo");
return ("");
}
*wp = 0;
strcat(wp, mp);
*adid = 1;
return (savestr(wbuf));
}
return (savestr(cp));
}
}
char *
domod(cp, type)
char *cp;
int type;
{
register char *wp, *xp;
register int c;
switch (type) {
case 'x':
case 'q':
wp = savestr(cp);
for (xp = wp; c = *xp; xp++)
if ((c != ' ' && c != '\t') || type == 'q')
*xp |= QUOTE;
return (wp);
case 'h':
case 't':
if (!any('/', cp))
return (0);
wp = strend(cp);
while (*--wp != '/')
continue;
if (type == 'h')
take:
xp = savestr(cp), xp[wp - cp] = 0;
else
xp = savestr(wp + 1);
return (xp);
case 'r':
wp = strend(cp);
for (wp--; wp >= cp && *wp != '.'; wp--)
if (*wp == '/')
return (0);
if (wp < cp)
return (0);
goto take;
}
return (0);
}
matchs(str, pat)
register char *str, *pat;
{
while (*str && *pat && *str == *pat)
str++, pat++;
return (*pat == 0);
}
getsel(al, ar, dol)
register int *al, *ar;
int dol;
{
register int c = getC(0);
register int i;
bool first = *al < 0;
switch (c) {
case '%':
if (quesarg == -1)
goto bad;
if (*al < 0)
*al = quesarg;
*ar = quesarg;
break;
case '-':
if (*al < 0) {
*al = 0;
*ar = dol - 1;
unreadc(c);
}
return (1);
case '^':
if (*al < 0)
*al = 1;
*ar = 1;
break;
case '$':
if (*al < 0)
*al = dol;
*ar = dol;
break;
case '*':
if (*al < 0)
*al = 1;
*ar = dol;
if (*ar < *al) {
*ar = 0;
*al = 1;
return (1);
}
break;
default:
if (digit(c)) {
i = 0;
while (digit(c)) {
i = i * 10 + c - '0';
c = getC(0);
}
if (i < 0)
i = dol + 1;
if (*al < 0)
*al = i;
*ar = i;
} else
if (*al < 0)
*al = 0, *ar = dol;
else
*ar = dol - 1;
unreadc(c);
break;
}
if (first) {
c = getC(0);
unreadc(c);
if (any(c, "-$*"))
return (1);
}
if (*al > *ar || *ar > dol) {
bad:
seterr("Bad ! arg selector");
return (0);
}
return (1);
}
struct wordent *
gethent(sc)
int sc;
{
register struct Hist *hp;
register char *np;
register int c;
int event;
bool back = 0;
c = sc == '^' ? '!' : getC(0);
switch (c) {
case ':':
case '^':
case '$':
case '*':
case '%':
ungetC(c);
if (lastev == eventno && alhistp)
return (alhistp);
event = lastev;
break;
case '!':
event = eventno;
break;
case '-':
back = 1;
c = getC(0);
goto number;
default:
if (any(c, "(=")) {
unreadc(c);
ungetC('!');
return (0);
}
if (digit(c))
goto number;
np = lhsb;
while (!any(c, ": \t\\\n}")) {
if (np < &lhsb[sizeof lhsb - 2])
*np++ = c;
c = getC(0);
}
unreadc(c);
if (np == lhsb) {
ungetC('!');
return (0);
}
*np++ = 0;
hp = findev(lhsb, 0);
if (hp)
lastev = hp->Hnum;
return (&hp->Hlex);
case '?':
np = lhsb;
for (;;) {
c = getC(0);
if (c == '\n') {
unreadc(c);
break;
}
if (c == '?')
break;
if (np < &lhsb[sizeof lhsb - 2])
*np++ = c;
}
if (np == lhsb) {
if (lhsb[0] == 0) {
seterr("No prev search");
return (0);
}
} else
*np++ = 0;
hp = findev(lhsb, 1);
if (hp)
lastev = hp->Hnum;
return (&hp->Hlex);
number:
event = 0;
while (digit(c)) {
event = event * 10 + c - '0';
c = getC(0);
}
if (back)
event = eventno + (alhistp == 0) - (event ? event : 0);
unreadc(c);
break;
}
for (hp = Histlist.Hnext; hp; hp = hp->Hnext)
if (hp->Hnum == event) {
hp->Href = eventno;
lastev = hp->Hnum;
return (&hp->Hlex);
}
np = putn(event);
noev(np);
return (0);
}
struct Hist *
findev(cp, anyarg)
char *cp;
bool anyarg;
{
register struct Hist *hp;
for (hp = Histlist.Hnext; hp; hp = hp->Hnext)
if (matchev(hp, cp, anyarg))
return (hp);
noev(cp);
return (0);
}
noev(cp)
char *cp;
{
seterr2(cp, ": Event not found");
}
matchev(hp, cp, anyarg)
register struct Hist *hp;
char *cp;
bool anyarg;
{
register char *dp;
struct wordent *lp = &hp->Hlex;
int argno = 0;
for (;;) {
lp = lp->next;
if (lp->word[0] == '\n')
return (0);
for (dp = lp->word; *dp; dp++) {
if (matchs(dp, cp)) {
if (anyarg)
quesarg = argno;
return (1);
}
if (!anyarg)
return (0);
}
argno++;
}
}
setexclp(cp)
register char *cp;
{
if (cp[0] == '\n')
return;
exclp = cp;
}
unreadc(c)
char c;
{
peekread = c;
}
readc(wanteof)
bool wanteof;
{
register int c;
if (c = peekread) {
peekread = 0;
return (c);
}
top:
if (alvecp) {
if (c = *alvecp++)
return (c);
if (*alvec) {
alvecp = *alvec++;
return (' ');
}
}
if (alvec) {
if (alvecp = *alvec) {
alvec++;
goto top;
}
/* Infinite source! */
return ('\n');
}
do {
if (arginp == (char *) 1 || onelflg == 1) {
if (wanteof)
return (-1);
exitstat();
}
if (arginp) {
if ((c = *arginp++) == 0) {
arginp = (char *) 1;
return ('\n');
}
return (c);
}
c = bgetc();
if (c < 0) {
#include <sgtty.h>
struct sgttyb tty;
if (wanteof)
return (-1);
/* was isatty but raw with ignoreeof yields problems */
if (adrof("ignoreeof") && gtty(SHIN, &tty)==0 && (tty.sg_flags & RAW) == 0) {
if (loginsh)
printf("\nUse \"logout\" to logout.\n");
else
printf("\nUse \"exit\" to leave csh.\n");
reset();
}
doneinp = 1;
reset();
}
if (c == '\n' && onelflg)
onelflg--;
} while (c == 0);
return (c);
}
bgetc()
{
register int buf, off, c;
#ifdef TELL
if (cantell) {
if (fseekp < fbobp || fseekp > feobp) {
fbobp = feobp = fseekp;
lseek(SHIN, fseekp, 0);
}
if (fseekp == feobp) {
fbobp = feobp;
do
c = read(SHIN, fbuf[0], BUFSIZ);
while (c < 0 && errno == EINTR);
if (c <= 0)
return (-1);
feobp += c;
}
c = fbuf[0][fseekp - fbobp];
fseekp++;
return (c);
}
#endif
again:
buf = (int) fseekp / BUFSIZ;
if (buf >= fblocks) {
register char **nfbuf = (char **) calloc(fblocks+2, sizeof (char **));
if (fbuf) {
blkcpy(nfbuf, fbuf);
xfree(fbuf);
}
fbuf = nfbuf;
fbuf[fblocks] = calloc(BUFSIZ, sizeof (char));
fblocks++;
goto again;
}
if (fseekp >= feobp) {
buf = (int) feobp / BUFSIZ;
off = (int) feobp % BUFSIZ;
do
c = read(SHIN, fbuf[buf] + off, BUFSIZ - off);
while (c < 0 && errno == EINTR);
if (c <= 0)
return (-1);
feobp += c;
goto again;
}
c = fbuf[buf][(int) fseekp % BUFSIZ];
fseekp++;
return (c);
}
bfree()
{
register int sb, i;
#ifdef TELL
if (cantell)
return;
#endif
if (whyles)
return;
sb = (int) (fseekp - 1) / BUFSIZ;
if (sb > 0) {
for (i = 0; i < sb; i++)
xfree(fbuf[i]);
blkcpy(fbuf, &fbuf[sb]);
fseekp -= BUFSIZ * sb;
feobp -= BUFSIZ * sb;
fblocks -= sb;
}
}
bseek(l)
long l;
{
register struct whyle *wp;
fseekp = l;
#ifdef TELL
if (!cantell) {
#endif
if (!whyles)
return;
for (wp = whyles; wp->w_next; wp = wp->w_next)
continue;
if (wp->w_start > l)
l = wp->w_start;
#ifdef TELL
}
#endif
}
/* any similarity to bell telephone is purely accidental */
long
btell()
{
return (fseekp);
}
btoeof()
{
lseek(SHIN, 0l, 2);
fseekp = feobp;
wfree();
bfree();
}
#ifdef TELL
settell()
{
cantell = 0;
if (arginp || onelflg || intty)
return;
if (lseek(SHIN, 0l, 1) < 0 || errno == ESPIPE)
return;
fbuf = (char **) calloc(2, sizeof (char **));
fblocks = 1;
fbuf[0] = calloc(BUFSIZ, sizeof (char));
fseekp = fbobp = feobp = tell(SHIN);
cantell = 1;
}
#endif