70d8efb393
fixed (there might be no way) - but it "feels right"! When popping an (exhausted) input string off the input stack, allow for the possibility that the previous string might also just happened to have run out of steam as well, so keep poppin' along until we run out of pop, or find something to consume.
579 lines
12 KiB
C
579 lines
12 KiB
C
/* $NetBSD: input.c,v 1.56 2017/05/03 06:20:12 kre Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. 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 <sys/cdefs.h>
|
|
#ifndef lint
|
|
#if 0
|
|
static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95";
|
|
#else
|
|
__RCSID("$NetBSD: input.c,v 1.56 2017/05/03 06:20:12 kre Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
|
|
#include <stdio.h> /* defines BUFSIZ */
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
|
|
/*
|
|
* This file implements the input routines used by the parser.
|
|
*/
|
|
|
|
#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 "myhistedit.h"
|
|
|
|
#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
|
|
|
|
MKINIT
|
|
struct strpush {
|
|
struct strpush *prev; /* preceding string on stack */
|
|
const char *prevstring;
|
|
int prevnleft;
|
|
int prevlleft;
|
|
struct alias *ap; /* if push was associated with an alias */
|
|
};
|
|
|
|
/*
|
|
* The parsefile structure pointed to by the global variable parsefile
|
|
* contains information about the current file being read.
|
|
*/
|
|
|
|
MKINIT
|
|
struct parsefile {
|
|
struct parsefile *prev; /* preceding file on stack */
|
|
int linno; /* current line */
|
|
int fd; /* file descriptor (or -1 if string) */
|
|
int nleft; /* number of chars left in this line */
|
|
int lleft; /* number of chars left in this buffer */
|
|
const char *nextc; /* next char in buffer */
|
|
char *buf; /* input buffer */
|
|
struct strpush *strpush; /* for pushing strings at this level */
|
|
struct strpush basestrpush; /* so pushing one is fast */
|
|
};
|
|
|
|
|
|
int plinno = 1; /* input line number */
|
|
int parsenleft; /* copy of parsefile->nleft */
|
|
MKINIT int parselleft; /* copy of parsefile->lleft */
|
|
const char *parsenextc; /* copy of parsefile->nextc */
|
|
MKINIT struct parsefile basepf; /* top level input file */
|
|
MKINIT char basebuf[BUFSIZ]; /* buffer for top level input file */
|
|
struct parsefile *parsefile = &basepf; /* current input file */
|
|
int init_editline = 0; /* editline library initialized? */
|
|
int whichprompt; /* 1 == PS1, 2 == PS2 */
|
|
|
|
STATIC void pushfile(void);
|
|
static int preadfd(void);
|
|
|
|
#ifdef mkinit
|
|
INCLUDE <stdio.h>
|
|
INCLUDE "input.h"
|
|
INCLUDE "error.h"
|
|
|
|
INIT {
|
|
basepf.nextc = basepf.buf = basebuf;
|
|
}
|
|
|
|
RESET {
|
|
if (exception != EXSHELLPROC)
|
|
parselleft = parsenleft = 0; /* clear input buffer */
|
|
popallfiles();
|
|
}
|
|
|
|
SHELLPROC {
|
|
popallfiles();
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Read a line from the script.
|
|
*/
|
|
|
|
char *
|
|
pfgets(char *line, int len)
|
|
{
|
|
char *p = line;
|
|
int nleft = len;
|
|
int c;
|
|
|
|
while (--nleft > 0) {
|
|
c = pgetc_macro();
|
|
if (c == PEOF) {
|
|
if (p == line)
|
|
return NULL;
|
|
break;
|
|
}
|
|
*p++ = c;
|
|
if (c == '\n')
|
|
break;
|
|
}
|
|
*p = '\0';
|
|
return line;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Read a character from the script, returning PEOF on end of file.
|
|
* Nul characters in the input are silently discarded.
|
|
*/
|
|
|
|
int
|
|
pgetc(void)
|
|
{
|
|
return pgetc_macro();
|
|
}
|
|
|
|
|
|
static int
|
|
preadfd(void)
|
|
{
|
|
int nr;
|
|
char *buf = parsefile->buf;
|
|
parsenextc = 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 = el_len == 0 ? 0 : -1;
|
|
else {
|
|
nr = el_len;
|
|
if (nr > BUFSIZ - 8)
|
|
nr = BUFSIZ - 8;
|
|
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, BUFSIZ - 8);
|
|
|
|
|
|
if (nr <= 0) {
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
nr = -1;
|
|
}
|
|
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.
|
|
*/
|
|
|
|
int
|
|
preadbuffer(void)
|
|
{
|
|
char *p, *q;
|
|
int more;
|
|
#ifndef SMALL
|
|
int something;
|
|
#endif
|
|
char savec;
|
|
|
|
while (parsefile->strpush) {
|
|
popstring();
|
|
if (--parsenleft >= 0)
|
|
return (*parsenextc++);
|
|
}
|
|
if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
|
|
return PEOF;
|
|
flushout(&output);
|
|
flushout(&errout);
|
|
|
|
again:
|
|
if (parselleft <= 0) {
|
|
if ((parselleft = preadfd()) == -1) {
|
|
parselleft = parsenleft = EOF_NLEFT;
|
|
return PEOF;
|
|
}
|
|
}
|
|
|
|
/* p = (not const char *)parsenextc; */
|
|
p = parsefile->buf + (parsenextc - parsefile->buf);
|
|
q = p;
|
|
|
|
/* delete nul characters */
|
|
#ifndef SMALL
|
|
something = 0;
|
|
#endif
|
|
for (more = 1; more;) {
|
|
switch (*p) {
|
|
case '\0':
|
|
p++; /* Skip nul */
|
|
goto check;
|
|
|
|
case '\t':
|
|
case ' ':
|
|
break;
|
|
|
|
case '\n':
|
|
parsenleft = q - parsenextc;
|
|
more = 0; /* Stop processing here */
|
|
break;
|
|
|
|
default:
|
|
#ifndef SMALL
|
|
something = 1;
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
*q++ = *p++;
|
|
check:
|
|
if (--parselleft <= 0) {
|
|
parsenleft = q - parsenextc - 1;
|
|
if (parsenleft < 0)
|
|
goto again;
|
|
*q = '\0';
|
|
more = 0;
|
|
}
|
|
}
|
|
|
|
savec = *q;
|
|
*q = '\0';
|
|
|
|
#ifndef SMALL
|
|
if (parsefile->fd == 0 && hist && something) {
|
|
HistEvent he;
|
|
INTOFF;
|
|
history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
|
|
parsenextc);
|
|
INTON;
|
|
}
|
|
#endif
|
|
|
|
if (vflag) {
|
|
out2str(parsenextc);
|
|
flushout(out2);
|
|
}
|
|
|
|
*q = savec;
|
|
|
|
return *parsenextc++;
|
|
}
|
|
|
|
/*
|
|
* Undo the last call to pgetc. Only one character may be pushed back.
|
|
* PEOF may be pushed back.
|
|
*/
|
|
|
|
void
|
|
pungetc(void)
|
|
{
|
|
parsenleft++;
|
|
parsenextc--;
|
|
}
|
|
|
|
/*
|
|
* Push a string back onto the input at this current parsefile level.
|
|
* We handle aliases this way.
|
|
*/
|
|
void
|
|
pushstring(const char *s, int len, struct alias *ap)
|
|
{
|
|
struct strpush *sp;
|
|
|
|
INTOFF;
|
|
/*debugprintf("*** 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 = parsenextc;
|
|
sp->prevnleft = parsenleft;
|
|
sp->prevlleft = parselleft;
|
|
sp->ap = ap;
|
|
if (ap)
|
|
ap->flag |= ALIASINUSE;
|
|
parsenextc = s;
|
|
parsenleft = len;
|
|
INTON;
|
|
}
|
|
|
|
void
|
|
popstring(void)
|
|
{
|
|
struct strpush *sp = parsefile->strpush;
|
|
|
|
INTOFF;
|
|
parsenextc = sp->prevstring;
|
|
parsenleft = sp->prevnleft;
|
|
parselleft = sp->prevlleft;
|
|
/*debugprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
|
|
if (sp->ap)
|
|
sp->ap->flag &= ~ALIASINUSE;
|
|
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.
|
|
*/
|
|
|
|
void
|
|
setinputfile(const char *fname, int push)
|
|
{
|
|
unsigned char magic[4];
|
|
int fd;
|
|
int fd2;
|
|
struct stat sb;
|
|
|
|
INTOFF;
|
|
if ((fd = open(fname, O_RDONLY)) < 0)
|
|
error("Can't open %s", fname);
|
|
|
|
/* Since the message "Syntax error: "(" unexpected" is not very
|
|
* helpful, we check if the file starts with the ELF magic to
|
|
* avoid that message. The first lseek tries to make sure that
|
|
* we can later rewind the file.
|
|
*/
|
|
if (fstat(fd, &sb) == 0 && S_ISREG(sb.st_mode) &&
|
|
lseek(fd, 0, SEEK_SET) == 0) {
|
|
if (read(fd, magic, 4) == 4) {
|
|
if (memcmp(magic, "\177ELF", 4) == 0) {
|
|
(void)close(fd);
|
|
error("Cannot execute ELF binary %s", fname);
|
|
}
|
|
}
|
|
if (lseek(fd, 0, SEEK_SET) != 0) {
|
|
(void)close(fd);
|
|
error("Cannot rewind the file %s", fname);
|
|
}
|
|
}
|
|
|
|
fd2 = to_upper_fd(fd); /* closes fd, returns higher equiv */
|
|
if (fd2 == fd) {
|
|
(void) close(fd);
|
|
error("Out of file descriptors");
|
|
}
|
|
|
|
setinputfd(fd2, push);
|
|
INTON;
|
|
}
|
|
|
|
/*
|
|
* When a shell fd needs to be altered (when the user wants to use
|
|
* the same fd - rare, but happens - we need to locate the ref to
|
|
* the fd, and update it. This happens via a callback.
|
|
* This is the callback func for fd's used for shell input
|
|
*/
|
|
static void
|
|
input_fd_swap(int from, int to)
|
|
{
|
|
struct parsefile *pf;
|
|
|
|
pf = parsefile;
|
|
while (pf != NULL) { /* don't need to stop at basepf */
|
|
if (pf->fd == from)
|
|
pf->fd = to;
|
|
pf = pf->prev;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Like setinputfile, but takes an open file descriptor. Call this with
|
|
* interrupts off.
|
|
*/
|
|
|
|
void
|
|
setinputfd(int fd, int push)
|
|
{
|
|
register_sh_fd(fd, input_fd_swap);
|
|
(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
|
|
if (push) {
|
|
pushfile();
|
|
parsefile->buf = ckmalloc(BUFSIZ);
|
|
}
|
|
if (parsefile->fd > 0)
|
|
sh_close(parsefile->fd);
|
|
parsefile->fd = fd;
|
|
if (parsefile->buf == NULL)
|
|
parsefile->buf = ckmalloc(BUFSIZ);
|
|
parselleft = parsenleft = 0;
|
|
plinno = 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* Like setinputfile, but takes input from a string.
|
|
*/
|
|
|
|
void
|
|
setinputstring(char *string, int push)
|
|
{
|
|
|
|
INTOFF;
|
|
if (push)
|
|
pushfile();
|
|
parsenextc = string;
|
|
parselleft = parsenleft = 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;
|
|
|
|
parsefile->nleft = parsenleft;
|
|
parsefile->lleft = parselleft;
|
|
parsefile->nextc = parsenextc;
|
|
parsefile->linno = plinno;
|
|
pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
|
|
pf->prev = parsefile;
|
|
pf->fd = -1;
|
|
pf->strpush = NULL;
|
|
pf->basestrpush.prev = NULL;
|
|
parsefile = pf;
|
|
}
|
|
|
|
|
|
void
|
|
popfile(void)
|
|
{
|
|
struct parsefile *pf = parsefile;
|
|
|
|
INTOFF;
|
|
if (pf->fd >= 0)
|
|
sh_close(pf->fd);
|
|
if (pf->buf)
|
|
ckfree(pf->buf);
|
|
while (pf->strpush)
|
|
popstring();
|
|
parsefile = pf->prev;
|
|
ckfree(pf);
|
|
parsenleft = parsefile->nleft;
|
|
parselleft = parsefile->lleft;
|
|
parsenextc = parsefile->nextc;
|
|
plinno = parsefile->linno;
|
|
INTON;
|
|
}
|
|
|
|
|
|
/*
|
|
* Return to top level.
|
|
*/
|
|
|
|
void
|
|
popallfiles(void)
|
|
{
|
|
while (parsefile != &basepf)
|
|
popfile();
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Close the file(s) that the shell is reading commands from. Called
|
|
* after a fork is done.
|
|
*
|
|
* Takes one arg, vfork, which tells it to not modify its global vars
|
|
* as it is still running in the parent.
|
|
*
|
|
* This code is (probably) unnecessary as the 'close on exec' flag is
|
|
* set and should be enough. In the vfork case it is definitely wrong
|
|
* to close the fds as another fork() may be done later to feed data
|
|
* from a 'here' document into a pipe and we don't want to close the
|
|
* pipe!
|
|
*/
|
|
|
|
void
|
|
closescript(int vforked)
|
|
{
|
|
if (vforked)
|
|
return;
|
|
popallfiles();
|
|
if (parsefile->fd > 0) {
|
|
sh_close(parsefile->fd);
|
|
parsefile->fd = 0;
|
|
}
|
|
}
|