release: rc-1.4

1 files changed, 368 insertions, 0 deletions

diff --git a/footobar.c b/footobar.c
new file mode 100644
index 0000000..f50db3c
--- /dev/null
+++ b/footobar.c
@@ -0,0 +1,368 @@
+/*
+   footobar.c: a collection of functions to convert internal representations of
+   variables and functions to external representations, and vice versa
+*/
+
+#include "rc.h"
+
+#define FSCHAR '\1'
+#define FSSTRING "\1"
+
+static char *getenvw(char *, bool);
+
+#ifdef PROTECT_ENV
+static bool Fconv(Format *f, int ignore) {	/* protect an exported name from brain-dead shells */
+	int c;
+	unsigned const char *s = va_arg(f->args, unsigned const char *);
+
+	while ((c = *s++) != '\0')
+		if (dnw[c] || c == '*' || (c == '_' && *s == '_'))
+			fmtprint(f, "__%02x", c);
+		else
+			fmtputc(f, c);
+	return FALSE;
+}
+#endif
+
+/* used to turn a function in Node * form into something we can export to the environment */
+
+extern char *fun2str(char *name, Node *n) {
+	return mprint("fn_%F={%T}", name, n);
+}
+
+/* convert a redirection to a printable form */
+
+static bool Dconv(Format *f, int ignore) {
+	const char *name = "?";
+	int n = va_arg(f->args, int);
+	switch (n) {
+	case rCreate:		name = ">";	break;
+	case rAppend:		name = ">>";	break;
+	case rFrom:		name = "<";	break;
+	case rHeredoc:		name = "<<";	break;
+	case rHerestring:	name = "<<<";	break;
+	}
+	fmtcat(f, name);
+	return FALSE;
+}
+
+/* defaultfd -- return the default fd for a given redirection operation */
+
+extern int defaultfd(int op) {
+	return (op == rCreate || op == rAppend) ? 1 : 0;
+}
+
+/* convert a function in Node * form into something rc can parse (and humans can read?) */
+
+static bool Tconv(Format *f, int ignore) {
+	Node *n = va_arg(f->args, Node *);
+	if (n == NULL) {
+		fmtprint(f, "()");
+		return FALSE;
+	}
+	switch (n->type) {
+	case nWord:	fmtprint(f, "%S", n->u[0].s);				break;
+	case nQword:	fmtprint(f, "%#S", n->u[0].s);				break;
+	case nBang:	fmtprint(f, "! %T", n->u[0].p);				break;
+	case nCase:	fmtprint(f, "case %T", n->u[0].p);			break;
+	case nNowait:	fmtprint(f, "%T&", n->u[0].p);				break;
+	case nCount:	fmtprint(f, "$#%T", n->u[0].p);				break;
+	case nFlat:	fmtprint(f, "$^%T", n->u[0].p);				break;
+	case nRmfn:	fmtprint(f, "fn %T", n->u[0].p);			break;
+	case nSubshell:	fmtprint(f, "@ %T", n->u[0].p);				break;
+	case nVar:	fmtprint(f, "$%T", n->u[0].p);				break;
+	case nAndalso:	fmtprint(f, "%T&&%T", n->u[0].p, n->u[1].p);		break;
+	case nAssign:	fmtprint(f, "%T=%T", n->u[0].p, n->u[1].p);		break;
+	case nConcat:	fmtprint(f, "%T^%T", n->u[0].p, n->u[1].p);		break;
+	case nElse:	fmtprint(f, "{%T}else %T", n->u[0].p, n->u[1].p);	break;
+	case nNewfn:	fmtprint(f, "fn %T {%T}", n->u[0].p, n->u[1].p);	break;
+	case nIf:	fmtprint(f, "if(%T)%T", n->u[0].p, n->u[1].p);		break;
+	case nOrelse:	fmtprint(f, "%T||%T", n->u[0].p, n->u[1].p);		break;
+	case nArgs:	fmtprint(f, "%T %T", n->u[0].p, n->u[1].p);		break;
+	case nSwitch:	fmtprint(f, "switch(%T){%T}", n->u[0].p, n->u[1].p);	break;
+	case nMatch:	fmtprint(f, "~ %T %T", n->u[0].p, n->u[1].p);		break;
+	case nVarsub:	fmtprint(f, "$%T(%T)", n->u[0].p, n->u[1].p);		break;
+	case nWhile:	fmtprint(f, "while(%T)%T", n->u[0].p, n->u[1].p);	break;
+	case nLappend:	fmtprint(f, "(%T %T)", n->u[0].p, n->u[1].p);		break;
+	case nForin:	fmtprint(f, "for(%T in %T)%T", n->u[0].p, n->u[1].p, n->u[2].p); break;
+	case nDup:
+		if (n->u[2].i != -1)
+			fmtprint(f, "%D[%d=%d]", n->u[0].i, n->u[1].i, n->u[2].i);
+		else
+			fmtprint(f, "%D[%d=]", n->u[0].i, n->u[1].i);
+		break;
+	case nBackq: {
+		Node *n0 = n->u[0].p, *n00;
+		if (n0 != NULL && n0->type == nVar
+		    && (n00 = n0->u[0].p) != NULL && n00->type == nWord && streq(n00->u[0].s, "ifs"))
+			fmtprint(f, "`");
+		else
+			fmtprint(f, "``%T", n0);
+		fmtprint(f, "{%T}", n->u[1].p);
+		break;
+	}
+	case nCbody:
+	case nBody: {
+		Node *n0 = n->u[0].p;
+		if (n0 != NULL)
+			fmtprint(f, "%T", n->u[0].p);
+		if (n->u[1].p != NULL) {
+			if (n0 != NULL && n0->type != nNowait)
+				fmtprint(f, ";");
+			fmtprint(f, "%T", n->u[1].p);
+		}
+		break;
+	}
+	case nBrace:
+		fmtprint(f, "{%T}", n->u[0].p);
+		if (n->u[1].p != NULL)
+			fmtprint(f, "%T", n->u[1].p);
+		break;
+	case nEpilog:
+	case nPre:
+		fmtprint(f, "%T", n->u[0].p);
+		if (n->u[1].p != NULL)
+			fmtprint(f, " %T", n->u[1].p);
+		break;
+	case nPipe: {
+		int ofd = n->u[0].i, ifd = n->u[1].i;
+		fmtprint(f, "%T|", n->u[2].p);
+		if (ifd != 0)
+			fmtprint(f, "[%d=%d]", ofd, ifd);
+		else if (ofd != 1)
+			fmtprint(f, "[%d]", ofd);
+		fmtprint(f, "%T", n->u[3].p);
+		break;
+	}
+	case nRedir: {
+		int op = n->u[0].i;
+		fmtprint(f, "%D", op);
+		if (n->u[1].i != defaultfd(op))
+			fmtprint(f, "[%d]", n->u[1].i);
+		fmtprint(f, "%T", n->u[2].p);
+		break;
+	}
+	case nNmpipe: {
+		int op = n->u[0].i;
+		fmtprint(f, "%D", op);
+		if (n->u[1].i != defaultfd(op))
+			fmtprint(f, "[%d]", n->u[1].i);
+		fmtprint(f, "{%T}", n->u[2].p);
+		break;
+	}
+ 	}
+	return FALSE;
+}
+
+/* convert a List to a string, separating it with ^A characters. Used for exporting variables to the environment */
+
+extern char *list2str(char *name, List *s) {
+	SIZE_T size, step;
+	List *t;
+	char *w, *x;
+	name = nprint("%F", name);
+	size = strlen(name) + listlen(s);
+	w = ealloc(size + 2);
+	t = s;
+	x = w;
+	strcpy(x, name);
+	strcpy(x += strlen(name), "=");
+	strcpy(x += conststrlen("="), t->w);
+	for (x += strlen(t->w), s = s->n; s != NULL; s = s->n) {
+		memcpy(x, FSSTRING, step = conststrlen(FSSTRING));
+		x += step;
+		memcpy(x, s->w, step = strlen(s->w));
+		x += step;
+	}
+	*x = '\0';
+	return w;
+}
+
+/* convert a List to an array, for execve() */
+
+extern char **list2array(List *s, bool print) {
+	char **av;
+	int i;
+
+	/* 4 == 1 for the null terminator + 2 for the fake execve() + 1 for defaulting to sh */
+	av = nalloc((listnel(s) + 4) * sizeof (char *));
+	av += 3; /* hide the two free spots from rc (two for #! emulation, one for defaulting to sh) */
+	if (print)
+		fprint(2, "%L\n", s, " ");
+	for (i = 0; s != NULL; i++) {
+		av[i] = s->w;
+		s = s->n;
+	}
+	av[i] = NULL;
+	return av;
+}
+
+/* figure out the name of a variable given an environment string. copy this into malloc space */
+
+extern char *get_name(char *s) {
+	int c;
+	SIZE_T i;
+	char *r, *namebuf;
+	for (i = 0; s[i] != '\0' && s[i] != '='; i++)
+		;
+	if (s[i] == '\0')
+		return NULL;
+	r = namebuf = ealloc(i + 1);
+	while (1)
+		switch (c = *s++) {
+		case '=':
+			*r++ = '\0';
+			return namebuf;
+#ifdef PROTECT_ENV
+		case '_':
+			if (*s == '_') {
+				static const char hexchar[] = "0123456789abcdef";
+				char *h1 = strchr(hexchar, s[1]);
+				char *h2 = strchr(hexchar, s[2]);
+				if (h1 != NULL && h2 != NULL) {
+					*r++ = ((h1 - hexchar) << 4) | (h2 - hexchar);
+					s += 3;
+					break;
+				}
+			}
+			/* FALLTHROUGH */
+#endif
+		default:
+			*r++ = c;
+			break;
+		}
+}
+
+/* get the next word from a variable's value as represented in the environment. */
+
+static char *getenvw(char *s, bool saw_alpha) {
+	SIZE_T i;
+	char *r;
+	for (i = 0; s[i] != '\0' && s[i] != FSCHAR; i++)
+		;
+	if (i == 0) {
+		if (s[i] == '\0' && !saw_alpha)
+			return NULL;
+		else
+			return clear(enew(char), (SIZE_T) 1);
+	}
+	r = strncpy(ealloc(i + 1), s, i);
+	r[i] = '\0';
+	return r;
+}
+
+/* take an environment entry for a variable (elements ^A separated) and turn it into a List */
+
+extern List *parse_var(char *name, char *extdef) {
+	List *r, *top;
+	char *f;
+	bool saw_alpha;
+	top = r = enew(List);
+	extdef = strchr(extdef, '=') + 1;
+	if ((f = getenvw(extdef, FALSE)) == NULL) {
+		r->w = "";
+		r->m = NULL;
+		r->n = NULL;
+	} else {
+		while (1) {
+			r->w = f;
+			r->m = NULL;
+			extdef += strlen(f);
+			if (*extdef == FSCHAR) {
+				extdef++;
+				saw_alpha = TRUE;
+			} else {
+				saw_alpha = FALSE;
+			}
+			if ((f = getenvw(extdef, saw_alpha)) == NULL) {
+				r->n = NULL;
+				break;
+			}
+			r = r->n = enew(List);
+		}
+	}
+	return top;
+}
+
+/* get an environment entry for a function and have rc parse it. */
+
+#define PREFIX "fn x"
+#define PRELEN conststrlen(PREFIX)
+extern Node *parse_fn(char *name, char *extdef) {
+	Node *def;
+	char *s, old[PRELEN];
+	if ((s = strchr(extdef, '=')) == NULL)
+		return NULL;
+	memcpy(old, s -= (PRELEN-1), PRELEN);
+	memcpy(s, PREFIX, PRELEN);
+	def = parseline(s);
+	memcpy(s, old, PRELEN);
+	return (def == NULL || def->type != nNewfn) ? NULL : def->u[1].p;
+}
+
+static bool Aconv(Format *f, int c) {
+	char **a = va_arg(f->args, char **);
+	if (*a != NULL) {
+		fmtcat(f, *a);
+		while (*++a != NULL)
+			fmtprint(f, " %s", *a);
+	}
+	return FALSE;
+}
+
+static bool Lconv(Format *f, int c) {
+	List *l = va_arg(f->args, List *);
+	char *sep = va_arg(f->args, char *);
+	char *fmt = (f->flags & FMT_leftside) ? "%s%s" : "%-S%s";
+	if (l == NULL && (f->flags & FMT_leftside) == 0)
+		fmtprint(f, "()");
+	else {
+		List *s;
+		for (s = l; s != NULL; s = s->n)
+			fmtprint(f, fmt, s->w, s->n == NULL ? "" : sep);
+	}
+	return FALSE;
+}
+
+#define	ISMETA(c)	(c == '*' || c == '?' || c == '[')
+
+static bool Sconv(Format *f, int ignore) {
+	int c;
+	unsigned char *s = va_arg(f->args, unsigned char *), *t = s;
+	bool quoted    = (f->flags & FMT_altform)  != 0;	/* '#' */
+	bool metaquote = (f->flags & FMT_leftside) != 0;	/* '-' */
+	if (*s == '\0') {
+		fmtprint(f, "''");
+		return FALSE;
+	}
+	if (!quoted) {
+		while ((c = *t++) != '\0')
+			if (nw[c] == 1 || (metaquote && ISMETA(c)))
+				goto quoteit;
+		fmtprint(f, "%s", s);
+		return FALSE;
+	}
+quoteit:
+	fmtputc(f, '\'');
+	while ((c = *s++) != '\0') {
+		fmtputc(f, c);
+		if (c == '\'')
+			fmtputc(f, '\'');
+
+	}
+	fmtputc(f, '\'');
+	return FALSE;
+}
+
+void initprint(void) {
+	fmtinstall('A', Aconv);
+	fmtinstall('L', Lconv);
+	fmtinstall('S', Sconv);
+	fmtinstall('T', Tconv);
+	fmtinstall('D', Dconv);
+#ifdef PROTECT_ENV
+	fmtinstall('F', Fconv);
+#else
+	fmtinstall('F', fmtinstall('s', NULL));
+#endif
+}