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-rw-r--r--bin/dash/src/input.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/bin/dash/src/input.c b/bin/dash/src/input.c
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+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>	/* defines BUFSIZ */
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * This file implements the input routines used by the parser.
+ */
+
+#include "eval.h"
+#include "shell.h"
+#include "redir.h"
+#include "syntax.h"
+#include "input.h"
+#include "output.h"
+#include "options.h"
+#include "memalloc.h"
+#include "error.h"
+#include "alias.h"
+#include "parser.h"
+#include "main.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+
+#define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
+#define IBUFSIZ (BUFSIZ + 1)
+
+
+MKINIT struct parsefile basepf;	/* top level input file */
+MKINIT char basebuf[IBUFSIZ];	/* buffer for top level input file */
+struct parsefile *parsefile = &basepf;	/* current input file */
+int whichprompt;		/* 1 == PS1, 2 == PS2 */
+
+STATIC void pushfile(void);
+static int preadfd(void);
+static void setinputfd(int fd, int push);
+static int preadbuffer(void);
+
+#ifdef mkinit
+INCLUDE <stdio.h>
+INCLUDE <unistd.h>
+INCLUDE "input.h"
+INCLUDE "error.h"
+
+INIT {
+	basepf.nextc = basepf.buf = basebuf;
+	basepf.linno = 1;
+}
+
+RESET {
+	/* clear input buffer */
+	basepf.lleft = basepf.nleft = 0;
+	popallfiles();
+}
+
+FORKRESET {
+	popallfiles();
+	if (parsefile->fd > 0) {
+		close(parsefile->fd);
+		parsefile->fd = 0;
+	}
+}
+#endif
+
+
+/*
+ * Read a character from the script, returning PEOF on end of file.
+ * Nul characters in the input are silently discarded.
+ */
+
+int
+pgetc(void)
+{
+	int c;
+
+	if (parsefile->unget)
+		return parsefile->lastc[--parsefile->unget];
+
+	if (--parsefile->nleft >= 0)
+		c = (signed char)*parsefile->nextc++;
+	else
+		c = preadbuffer();
+
+	parsefile->lastc[1] = parsefile->lastc[0];
+	parsefile->lastc[0] = c;
+
+	return c;
+}
+
+
+/*
+ * Same as pgetc(), but ignores PEOA.
+ */
+
+int
+pgetc2()
+{
+	int c;
+	do {
+		c = pgetc();
+	} while (c == PEOA);
+	return c;
+}
+
+
+static int
+preadfd(void)
+{
+	int nr;
+	char *buf =  parsefile->buf;
+	parsefile->nextc = buf;
+
+retry:
+#ifndef SMALL
+	if (parsefile->fd == 0 && el) {
+		static const char *rl_cp;
+		static int el_len;
+
+		if (rl_cp == NULL)
+			rl_cp = el_gets(el, &el_len);
+		if (rl_cp == NULL)
+			nr = 0;
+		else {
+			nr = el_len;
+			if (nr > IBUFSIZ - 1)
+				nr = IBUFSIZ - 1;
+			memcpy(buf, rl_cp, nr);
+			if (nr != el_len) {
+				el_len -= nr;
+				rl_cp += nr;
+			} else
+				rl_cp = 0;
+		}
+
+	} else
+#endif
+		nr = read(parsefile->fd, buf, IBUFSIZ - 1);
+
+
+	if (nr < 0) {
+		if (errno == EINTR)
+			goto retry;
+		if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
+			int flags = fcntl(0, F_GETFL, 0);
+			if (flags >= 0 && flags & O_NONBLOCK) {
+				flags &=~ O_NONBLOCK;
+				if (fcntl(0, F_SETFL, flags) >= 0) {
+					out2str("sh: turning off NDELAY mode\n");
+					goto retry;
+				}
+			}
+		}
+	}
+	return nr;
+}
+
+/*
+ * Refill the input buffer and return the next input character:
+ *
+ * 1) If a string was pushed back on the input, pop it;
+ * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
+ *    from a string so we can't refill the buffer, return EOF.
+ * 3) If the is more stuff in this buffer, use it else call read to fill it.
+ * 4) Process input up to the next newline, deleting nul characters.
+ */
+
+static int preadbuffer(void)
+{
+	char *q;
+	int more;
+#ifndef SMALL
+	int something;
+#endif
+	char savec;
+
+	if (unlikely(parsefile->strpush)) {
+		if (
+			parsefile->nleft == -1 &&
+			parsefile->strpush->ap &&
+			parsefile->nextc[-1] != ' ' &&
+			parsefile->nextc[-1] != '\t'
+		) {
+			return PEOA;
+		}
+		popstring();
+		return pgetc();
+	}
+	if (unlikely(parsefile->nleft == EOF_NLEFT ||
+		     parsefile->buf == NULL))
+		return PEOF;
+	flushall();
+
+	more = parsefile->lleft;
+	if (more <= 0) {
+again:
+		if ((more = preadfd()) <= 0) {
+			parsefile->lleft = parsefile->nleft = EOF_NLEFT;
+			return PEOF;
+		}
+	}
+
+	q = parsefile->nextc;
+
+	/* delete nul characters */
+#ifndef SMALL
+	something = 0;
+#endif
+	for (;;) {
+		int c;
+
+		more--;
+		c = *q;
+
+		if (!c)
+			memmove(q, q + 1, more);
+		else {
+			q++;
+
+			if (c == '\n') {
+				parsefile->nleft = q - parsefile->nextc - 1;
+				break;
+			}
+
+#ifndef SMALL
+			switch (c) {
+			default:
+				something = 1;
+				/* fall through */
+			case '\t':
+			case ' ':
+				break;
+			}
+#endif
+		}
+
+		if (more <= 0) {
+			parsefile->nleft = q - parsefile->nextc - 1;
+			if (parsefile->nleft < 0)
+				goto again;
+			break;
+		}
+	}
+	parsefile->lleft = more;
+
+	savec = *q;
+	*q = '\0';
+
+#ifndef SMALL
+	if (parsefile->fd == 0 && hist && something) {
+		HistEvent he;
+		INTOFF;
+		history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
+			parsefile->nextc);
+		INTON;
+	}
+#endif
+
+	if (vflag) {
+		out2str(parsefile->nextc);
+#ifdef FLUSHERR
+		flushout(out2);
+#endif
+	}
+
+	*q = savec;
+
+	return (signed char)*parsefile->nextc++;
+}
+
+/*
+ * Undo a call to pgetc.  Only two characters may be pushed back.
+ * PEOF may be pushed back.
+ */
+
+void
+pungetc(void)
+{
+	parsefile->unget++;
+}
+
+/*
+ * Push a string back onto the input at this current parsefile level.
+ * We handle aliases this way.
+ */
+void
+pushstring(char *s, void *ap)
+{
+	struct strpush *sp;
+	size_t len;
+
+	len = strlen(s);
+	INTOFF;
+/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
+	if (parsefile->strpush) {
+		sp = ckmalloc(sizeof (struct strpush));
+		sp->prev = parsefile->strpush;
+		parsefile->strpush = sp;
+	} else
+		sp = parsefile->strpush = &(parsefile->basestrpush);
+	sp->prevstring = parsefile->nextc;
+	sp->prevnleft = parsefile->nleft;
+	sp->unget = parsefile->unget;
+	memcpy(sp->lastc, parsefile->lastc, sizeof(sp->lastc));
+	sp->ap = (struct alias *)ap;
+	if (ap) {
+		((struct alias *)ap)->flag |= ALIASINUSE;
+		sp->string = s;
+	}
+	parsefile->nextc = s;
+	parsefile->nleft = len;
+	parsefile->unget = 0;
+	INTON;
+}
+
+void
+popstring(void)
+{
+	struct strpush *sp = parsefile->strpush;
+
+	INTOFF;
+	if (sp->ap) {
+		if (parsefile->nextc[-1] == ' ' ||
+		    parsefile->nextc[-1] == '\t') {
+			checkkwd |= CHKALIAS;
+		}
+		if (sp->string != sp->ap->val) {
+			ckfree(sp->string);
+		}
+		sp->ap->flag &= ~ALIASINUSE;
+		if (sp->ap->flag & ALIASDEAD) {
+			unalias(sp->ap->name);
+		}
+	}
+	parsefile->nextc = sp->prevstring;
+	parsefile->nleft = sp->prevnleft;
+	parsefile->unget = sp->unget;
+	memcpy(parsefile->lastc, sp->lastc, sizeof(sp->lastc));
+/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
+	parsefile->strpush = sp->prev;
+	if (sp != &(parsefile->basestrpush))
+		ckfree(sp);
+	INTON;
+}
+
+/*
+ * Set the input to take input from a file.  If push is set, push the
+ * old input onto the stack first.
+ */
+
+int
+setinputfile(const char *fname, int flags)
+{
+	int fd;
+
+	INTOFF;
+	if ((fd = open64(fname, O_RDONLY)) < 0) {
+		if (flags & INPUT_NOFILE_OK)
+			goto out;
+		exitstatus = 127;
+		exerror(EXERROR, "Can't open %s", fname);
+	}
+	if (fd < 10)
+		fd = savefd(fd, fd);
+	setinputfd(fd, flags & INPUT_PUSH_FILE);
+out:
+	INTON;
+	return fd;
+}
+
+
+/*
+ * Like setinputfile, but takes an open file descriptor.  Call this with
+ * interrupts off.
+ */
+
+static void
+setinputfd(int fd, int push)
+{
+	if (push) {
+		pushfile();
+		parsefile->buf = 0;
+	}
+	parsefile->fd = fd;
+	if (parsefile->buf == NULL)
+		parsefile->buf = ckmalloc(IBUFSIZ);
+	parsefile->lleft = parsefile->nleft = 0;
+	plinno = 1;
+}
+
+
+/*
+ * Like setinputfile, but takes input from a string.
+ */
+
+void
+setinputstring(char *string)
+{
+	INTOFF;
+	pushfile();
+	parsefile->nextc = string;
+	parsefile->nleft = strlen(string);
+	parsefile->buf = NULL;
+	plinno = 1;
+	INTON;
+}
+
+
+
+/*
+ * To handle the "." command, a stack of input files is used.  Pushfile
+ * adds a new entry to the stack and popfile restores the previous level.
+ */
+
+STATIC void
+pushfile(void)
+{
+	struct parsefile *pf;
+
+	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
+	pf->prev = parsefile;
+	pf->fd = -1;
+	pf->strpush = NULL;
+	pf->basestrpush.prev = NULL;
+	pf->unget = 0;
+	parsefile = pf;
+}
+
+
+void
+popfile(void)
+{
+	struct parsefile *pf = parsefile;
+
+	INTOFF;
+	if (pf->fd >= 0)
+		close(pf->fd);
+	if (pf->buf)
+		ckfree(pf->buf);
+	while (pf->strpush)
+		popstring();
+	parsefile = pf->prev;
+	ckfree(pf);
+	INTON;
+}
+
+
+void unwindfiles(struct parsefile *stop)
+{
+	while (parsefile != stop)
+		popfile();
+}
+
+
+/*
+ * Return to top level.
+ */
+
+void
+popallfiles(void)
+{
+	unwindfiles(&basepf);
+}