/*
* extract a variable name
*/
static Bufblock*
varname(char **s)
{
Bufblock *b;
char *cp;
Rune r;
int n;
b = newbuf();
cp = *s;
for(;;){
n = chartorune(&r, cp);
if (!WORDCHR(r))
break;
rinsert(b, r);
cp += n;
}
if (b->current == b->start){
SYNERR(-1);
fprint(2, "missing variable name <%s>\n", *s);
freebuf(b);
return 0;
}
*s = cp;
insert(b, 0);
return b;
}
/*
* Input an escaped token. Possible escape chars are single-quote,
* double-quote and backslash. Only the first is a valid escape for
* rc; the others are just inserted into the receiving buffer.
*/
int
escapetoken(Biobuf *bp, Bufblock *buf, int preserve, int esc)
{
int c, line;
if(esc != '\'')
return 1;
line = mkinline;
while((c = nextrune(bp, 0)) > 0){
if(c == '\''){
if(preserve)
rinsert(buf, c);
c = Bgetrune(bp);
if (c < 0)
break;
if(c != '\''){
Bungetrune(bp);
return 1;
}
}
rinsert(buf, c);
}
SYNERR(line); fprint(2, "missing closing %c\n", esc);
return 0;
}
static Word*
expandvar(char **s)
{
Word *w;
Bufblock *buf;
Symtab *sym;
char *cp, *begin, *end;
begin = *s;
(*s)++; /* skip the '{' */
buf = varname(s);
if (buf == 0)
return 0;
cp = *s;
if (*cp == '}') { /* ${name} variant*/
(*s)++; /* skip the '}' */
w = varmatch(buf->start, s);
freebuf(buf);
return w;
}
if (*cp != ':') {
SYNERR(-1);
fprint(2, "bad variable name <%s>\n", buf->start);
freebuf(buf);
return 0;
}
cp++;
end = charin(cp , "}");
if(end == 0){
SYNERR(-1);
fprint(2, "missing '}': %s\n", begin);
Exit();
}
*end = 0;
*s = end+1;
sym = symlook(buf->start, S_VAR, 0);
if(sym == 0 || sym->value == 0)
w = newword(buf->start);
else
w = subsub((Word*) sym->value, cp, end);
freebuf(buf);
return w;
}
/*
* skip a token in quotes.
*/
static char *
squote(char *cp, int c)
{
Rune r;
int n;
while(*cp){
n = chartorune(&r, cp);
if(r == c)
return cp;
if(r == '\\')
n += chartorune(&r, cp+n);
cp += n;
}
SYNERR(-1); /* should never occur */
fprint(2, "missing closing '\n");
return 0;
}
/*
* search a string for unescaped characters in a pattern set
*/
static char *
shcharin(char *cp, char *pat)
{
Rune r;
int n, vargen;
vargen = 0;
while(*cp){
n = chartorune(&r, cp);
switch(r){
case '\\': /* skip escaped char */
cp += n;
n = chartorune(&r, cp);
break;
case '\'': /* skip quoted string */
case '"':
cp = squote(cp+1, r); /* n must = 1 */
if(!cp)
return 0;
break;
case '$':
if(*(cp+1) == '{')
vargen = 1;
break;
case '}':
if(vargen)
vargen = 0;
else if(utfrune(pat, r))
return cp;
break;
default:
if(vargen == 0 && utfrune(pat, r))
return cp;
break;
}
cp += n;
}
if(vargen){
SYNERR(-1);
fprint(2, "missing closing } in pattern generator\n");
}
return 0;
}
/*
* assemble a back-quoted shell command into a buffer
*/
static int
bquote(Biobuf *bp, Bufblock *buf)
{
int c, line, term, depth;
int start;
line = mkinline;
while((c = Bgetrune(bp)) == ' ' || c == '\t')
;
if(c == '{'){
term = '}'; /* rc style */
while((c = Bgetrune(bp)) == ' ' || c == '\t')
;
} else
term = '`'; /* sh style */
depth = 1;
start = buf->current-buf->start;
for(;c > 0; c = nextrune(bp, 0)){
if(c == '{' && term == '}')
depth++;
if(c == term && --depth == 0){
insert(buf, '\n');
insert(buf,0);
buf->current = buf->start+start;
execinit();
execsh(0, buf->current, buf, envy);
return 1;
}
if(c == '\n')
break;
if(c == '\'' || c == '"' || c == '\\'){
insert(buf, c);
if(!escapetoken(bp, buf, 1, c))
return 0;
continue;
}
rinsert(buf, c);
}
SYNERR(line);
fprint(2, "missing closing %c after `\n", term);
return 0;
}
/*
* Input an escaped token. Possible escape chars are single-quote,
* double-quote and backslash.
*/
static int
shescapetoken(Biobuf *bp, Bufblock *buf, int preserve, int esc)
{
int c, line;
if(esc == '\\') {
c = Bgetrune(bp);
if(c == '\r')
c = Bgetrune(bp);
if (c == '\n')
mkinline++;
rinsert(buf, c);
return 1;
}
line = mkinline;
while((c = nextrune(bp, 0)) >= 0){
if(c == esc){
if(preserve)
rinsert(buf, c);
return 1;
}
if(c == '\\') {
rinsert(buf, c);
c = Bgetrune(bp);
if(c == '\r')
c = Bgetrune(bp);
if (c < 0)
break;
if (c == '\n')
mkinline++;
}
rinsert(buf, c);
}
SYNERR(line); fprint(2, "missing closing %c\n", esc);
return 0;
}
void
parse(char *f, int fd, int varoverride)
{
int hline;
char *body;
Word *head, *tail;
int attr, set, pid;
char *prog, *p;
int newfd;
Biobuf in;
Bufblock *buf;
if(fd < 0) {
perror(f);
Exit();
}
ipush();
infile = strdup(f);
mkinline = 1;
Binit(&in, fd, OREAD);
buf = newbuf();
while(assline(&in, buf)) {
hline = mkinline;
switch(rhead(buf->start, &head, &tail, &attr, &prog))
{
case '<':
p = wtos(tail, ' ');
if(*p == 0) {
SYNERR(-1);
fprint(2, "missing include file name\n");
Exit();
}
newfd = open(p, OREAD);
if(newfd < 0) {
fprint(2, "warning: skipping missing include file: ");
perror(p);
} else
parse(p, newfd, 0);
break;
case '|':
p = wtos(tail, ' ');
if(*p == 0) {
SYNERR(-1);
fprint(2, "missing include program name\n");
Exit();
}
execinit();
pid=pipecmd(p, envy, &newfd);
if(newfd < 0) {
fprint(2, "warning: skipping missing program file: ");
perror(p);
} else
parse(p, newfd, 0);
while(waitup(-3, &pid) >= 0)
;
if(pid != 0) {
fprint(2, "bad include program status\n");
Exit();
}
break;
case ':':
body = rbody(&in);
addrules(head, tail, body, attr, hline, prog);
break;
case '=':
if(head->next) {
SYNERR(-1);
fprint(2, "multiple vars on left side of assignment\n");
Exit();
}
if(symlook(head->s, S_OVERRIDE, 0)) {
set = varoverride;
} else {
set = 1;
if(varoverride)
symlook(head->s, S_OVERRIDE, (void *)"");
}
if(set) {
/*
char *cp;
dumpw("tail", tail);
cp = wtos(tail, ' '); print("assign %s to %s\n", head->s, cp); free(cp);
*/
setvar(head->s, (void *) tail);
symlook(head->s, S_WESET, (void *)"");
}
if(attr)
symlook(head->s, S_NOEXPORT, (void *)"");
break;
default:
SYNERR(hline);
fprint(2, "expected one of :<=\n");
Exit();
break;
}
}
close(fd);
freebuf(buf);
ipop();
}
static int
rhead(char *line, Word **h, Word **t, int *attr, char **prog)
{
char *p;
char *pp;
int sep;
Rune r;
int n;
Word *w;
p = charin(line,":=<");
if(p == 0)
return('?');
sep = *p;
*p++ = 0;
if(sep == '<' && *p == '|') {
sep = '|';
p++;
}
*attr = 0;
*prog = 0;
if(sep == '=') {
pp = charin(p, termchars); /* termchars is shell-dependent */
if (pp && *pp == '=') {
while (p != pp) {
n = chartorune(&r, p);
switch(r)
{
default:
SYNERR(-1);
fprint(2, "unknown attribute '%c'\n",*p);
Exit();
case 'U':
*attr = 1;
break;
}
p += n;
}
p++; /* skip trailing '=' */
}
}
if((sep == ':') && *p && (*p != ' ') && (*p != '\t')) {
while (*p) {
n = chartorune(&r, p);
if (r == ':')
break;
p += n;
switch(r)
{
default:
SYNERR(-1);
fprint(2, "unknown attribute '%c'\n", p[-1]);
Exit();
case 'D':
*attr |= DEL;
break;
case 'E':
*attr |= NOMINUSE;
break;
case 'n':
*attr |= NOVIRT;
break;
case 'N':
*attr |= NOREC;
break;
case 'P':
pp = utfrune(p, ':');
if (pp == 0 || *pp == 0)
goto eos;
*pp = 0;
*prog = strdup(p);
*pp = ':';
p = pp;
break;
case 'Q':
*attr |= QUIET;
break;
case 'R':
*attr |= REGEXP;
break;
case 'U':
*attr |= UPD;
break;
case 'V':
*attr |= VIR;
break;
}
}
if (*p++ != ':') {
eos:
SYNERR(-1);
fprint(2, "missing trailing :\n");
Exit();
}
}
*h = w = stow(line);
if(*w->s == 0 && sep != '<' && sep != '|') {
SYNERR(mkinline-1);
fprint(2, "no var on left side of assignment/rule\n");
Exit();
}
*t = stow(p);
return(sep);
}
