2BSD/src/csh/sh.parse.c
/* Copyright (c) 1979 Regents of the University of California */
#include "sh.h"
/*
* C shell
*/
/*
* Perform aliasing on the word list lex
* Do a (very rudimentary) parse to separate into commands.
* If word 0 of a command has an alias, do it.
* Repeat a maximum of 20 times.
*/
alias(lex)
register struct wordent *lex;
{
int aleft = 21;
jmp_buf osetexit;
getexit(osetexit);
setexit();
if (haderr) {
resexit(osetexit);
reset();
}
if (--aleft == 0)
error("Alias loop");
asyntax(lex->next, lex);
resexit(osetexit);
}
asyntax(p1, p2)
register struct wordent *p1, *p2;
{
while (p1 != p2)
if (any(p1->word[0], ";&\n"))
p1 = p1->next;
else {
asyn0(p1, p2);
return;
}
}
asyn0(p1, p2)
struct wordent *p1;
register struct wordent *p2;
{
register struct wordent *p;
register int l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
if (l < 0)
error("Too many )'s");
continue;
case '>':
if (p->next != p2 && eq(p->next->word, "&"))
p = p->next;
continue;
case '&':
case '|':
case ';':
case '\n':
if (l != 0)
continue;
asyn3(p1, p);
asyntax(p->next, p2);
return;
}
if (l == 0)
asyn3(p1, p2);
}
asyn3(p1, p2)
struct wordent *p1;
register struct wordent *p2;
{
register struct varent *ap;
struct wordent alout;
register bool redid;
if (p1 == p2)
return;
if (p1->word[0] == '(') {
for (p2 = p2->prev; p2->word[0] != ')'; p2 = p2->prev)
if (p2 == p1)
return;
if (p2 == p1->next)
return;
asyn0(p1->next, p2);
return;
}
ap = adrof1(p1->word, &aliases);
if (ap == 0)
return;
alhistp = p1->prev;
alhistt = p2;
alvec = ap->vec;
redid = lex(&alout);
alhistp = alhistt = 0;
alvec = 0;
if (err) {
freelex(&alout);
error(err);
}
if (p1->word[0] && eq(p1->word, alout.next->word)) {
char *cp = alout.next->word;
alout.next->word = strspl("\200", cp);
xfree(cp);
}
p1 = freenod(p1, redid ? p2 : p1->next);
if (alout.next != &alout) {
p1->next->prev = alout.prev->prev;
alout.prev->prev->next = p1->next;
alout.next->prev = p1;
p1->next = alout.next;
xfree(alout.prev->word);
xfree(alout.prev);
}
reset(); /* throw! */
}
struct wordent *
freenod(p1, p2)
register struct wordent *p1, *p2;
{
register struct wordent *retp = p1->prev;
while (p1 != p2) {
xfree(p1->word);
p1 = p1->next;
xfree(p1->prev);
}
retp->next = p2;
p2->prev = retp;
return (retp);
}
#define PHERE 1
#define PIN 2
#define POUT 4
#define PDIAG 8
/*
* syntax
* empty
* syn0
*/
struct command *
syntax(p1, p2, flags)
register struct wordent *p1, *p2;
int flags;
{
while (p1 != p2)
if (any(p1->word[0], ";&\n"))
p1 = p1->next;
else
return (syn0(p1, p2, flags));
return (0);
}
/*
* syn0
* syn1
* syn1 & syntax
*/
struct command *
syn0(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p;
register struct command *t, *t1;
int l;
l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
if (l < 0)
seterr("Too many )'s");
continue;
case '|':
if (p->word[1] == '|')
continue;
/* fall into ... */
case '>':
if (p->next != p2 && eq(p->next->word, "&"))
p = p->next;
continue;
case '&':
if (l != 0)
break;
if (p->word[1] == '&')
continue;
t1 = syn1(p1, p, flags);
if (t1->t_dtyp == TLST) {
t = (struct command *) calloc(1, sizeof (*t));
t->t_dtyp = TPAR;
t->t_dflg = FAND|FPRS|FINT;
t->t_dspr = t1;
t1 = t;
} else
t1->t_dflg |= FAND|FPRS|FINT;
t = (struct command *) calloc(1, sizeof (*t));
t->t_dtyp = TLST;
t->t_dflg = 0;
t->t_dcar = t1;
t->t_dcdr = syntax(p, p2, flags);
return(t);
}
if (l == 0)
return (syn1(p1, p2, flags));
seterr("Too many ('s");
return (0);
}
/*
* syn1
* syn1a
* syn1a ; syntax
*/
struct command *
syn1(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p;
register struct command *t;
int l;
l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
continue;
case ';':
case '\n':
if (l != 0)
break;
t = (struct command *) calloc(1, sizeof (*t));
t->t_dtyp = TLST;
t->t_dcar = syn1a(p1, p, flags);
t->t_dcdr = syntax(p->next, p2, flags);
if (t->t_dcdr == 0)
t->t_dcdr = t->t_dcar, t->t_dcar = 0;
return (t);
}
return (syn1a(p1, p2, flags));
}
/*
* syn1a
* syn1b
* syn1b || syn1a
*/
struct command *
syn1a(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p;
register struct command *t;
register int l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
continue;
case '|':
if (p->word[1] != '|')
continue;
if (l == 0) {
t = (struct command *) calloc(1, sizeof (*t));
t->t_dtyp = TOR;
t->t_dcar = syn1b(p1, p, flags);
t->t_dcdr = syn1a(p->next, p2, flags);
t->t_dflg = 0;
return (t);
}
continue;
}
return (syn1b(p1, p2, flags));
}
/*
* syn1b
* syn2
* syn2 && syn1b
*/
struct command *
syn1b(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p;
register struct command *t;
register int l = 0;
l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
continue;
case '&':
if (p->word[1] == '&' && l == 0) {
t = (struct command *) calloc(1, sizeof (*t));
t->t_dtyp = TAND;
t->t_dcar = syn2(p1, p, flags);
t->t_dcdr = syn1b(p->next, p2, flags);
t->t_dflg = 0;
return (t);
}
continue;
}
return (syn2(p1, p2, flags));
}
/*
* syn2
* syn3
* syn3 | syn2
* syn3 |& syn2
*/
struct command *
syn2(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p, *pn;
register struct command *t;
register int l = 0;
int f;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
l++;
continue;
case ')':
l--;
continue;
case '|':
if (l != 0)
continue;
t = (struct command *) calloc(1, sizeof (*t));
f = flags | POUT;
pn = p->next;
if (pn != p2 && pn->word[0] == '&') {
f |= PDIAG;
t->t_dflg |= FDIAG;
}
t->t_dtyp = TFIL;
t->t_dcar = syn3(p1, p, f);
if (pn != p2 && pn->word[0] == '&')
p = pn;
t->t_dcdr = syn2(p->next, p2, flags | PIN);
return (t);
}
return (syn3(p1, p2, flags));
}
char *RELPAR = "<>()";
/*
* syn3
* ( syn0 ) [ < in ] [ > out ]
* word word* [ < in ] [ > out ]
* KEYWORD ( word* ) word* [ < in ] [ > out ]
*
* KEYWORD = (@ exit foreach if set switch test while)
*/
struct command *
syn3(p1, p2, flags)
struct wordent *p1, *p2;
int flags;
{
register struct wordent *p;
struct wordent *lp, *rp;
register struct command *t;
register int l;
char **av;
int n, c;
bool specp = 0;
if (p1 != p2) {
p = p1;
again:
switch (srchx(p->word)) {
case ZELSE:
p = p->next;
if (p != p2)
goto again;
break;
case ZEXIT:
case ZFOREACH:
case ZIF:
case ZLET:
case ZSET:
case ZSWITCH:
case ZWHILE:
specp = 1;
break;
}
}
n = 0;
l = 0;
for (p = p1; p != p2; p = p->next)
switch (p->word[0]) {
case '(':
if (specp)
n++;
l++;
continue;
case ')':
if (specp)
n++;
l--;
continue;
case '>':
case '<':
if (l != 0) {
if (specp)
n++;
continue;
}
if (p->next == p2)
continue;
if (any(p->next->word[0], RELPAR))
continue;
n--;
continue;
default:
if (!specp && l != 0)
continue;
n++;
continue;
}
if (n < 0)
n = 0;
t = (struct command *) calloc(1, sizeof (*t));
av = (char **) calloc(n + 1, sizeof (char **));
t->t_dcom = av;
n = 0;
if (p2->word[0] == ')')
t->t_dflg = FPAR;
lp = 0;
rp = 0;
l = 0;
for (p = p1; p != p2; p = p->next) {
c = p->word[0];
switch (c) {
case '(':
if (l == 0) {
if (lp != 0 && !specp)
seterr("Badly placed (");
lp = p->next;
}
l++;
goto savep;
case ')':
l--;
if (l == 0)
rp = p;
goto savep;
case '>':
if (l != 0)
goto savep;
if (p->word[1] == '>')
t->t_dflg |= FCAT;
if (p->next != p2 && eq(p->next->word, "&")) {
t->t_dflg |= FDIAG, p = p->next;
if (flags & (POUT|PDIAG))
goto badout;
}
if (p->next != p2 && eq(p->next->word, "!"))
t->t_dflg |= FANY, p = p->next;
if (p->next == p2) {
missfile:
seterr("Missing name for redirect");
continue;
}
p = p->next;
if (any(p->word[0], RELPAR))
goto missfile;
if ((flags & POUT) && (flags & PDIAG) == 0 || t->t_drit)
badout:
seterr("Ambiguous output redirect");
else
t->t_drit = savestr(p->word);
continue;
case '<':
if (l != 0)
goto savep;
if (p->word[1] == '<')
t->t_dflg |= FHERE;
if (p->next == p2)
goto missfile;
p = p->next;
if (any(p->word[0], RELPAR))
goto missfile;
if ((flags & PHERE) && (t->t_dflg & FHERE))
seterr("Can't << within ()'s");
else if ((flags & PIN) || t->t_dlef)
seterr("Ambiguous input redirect");
else
t->t_dlef = savestr(p->word);
continue;
savep:
if (!specp)
continue;
default:
if (l != 0 && !specp)
continue;
if (err == 0)
av[n] = savestr(p->word);
n++;
continue;
}
}
if (lp != 0 && !specp) {
if (n != 0)
seterr("Badly placed ()'s");
t->t_dtyp = TPAR;
t->t_dspr = syn0(lp, rp, PHERE);
} else {
if (n == 0)
seterr("Invalid null command");
t->t_dtyp = TCOM;
}
return (t);
}
freesyn(t)
register struct command *t;
{
register char **v;
if (t == 0)
return;
switch (t->t_dtyp) {
case TCOM:
for (v = t->t_dcom; *v; v++)
xfree(*v);
xfree(t->t_dcom);
goto lr;
case TPAR:
freesyn(t->t_dspr);
/* fall into ... */
lr:
xfree(t->t_dlef), xfree(t->t_drit);
break;
case TAND:
case TOR:
case TFIL:
case TLST:
freesyn(t->t_dcar), freesyn(t->t_dcdr);
break;
}
xfree(t);
}