4.4BSD/usr/src/bin/sh/input.c
/*-
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
static char sccsid[] = "@(#)input.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
/*
* This file implements the input routines used by the parser.
*/
#include <stdio.h> /* defines BUFSIZ */
#include "shell.h"
#include <fcntl.h>
#include <errno.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 */
char *prevstring;
int prevnleft;
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 buffer */
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 */
MKINIT int parsenleft; /* copy of parsefile->nleft */
char *parsenextc; /* copy of parsefile->nextc */
MKINIT struct parsefile basepf; /* top level input file */
char basebuf[BUFSIZ]; /* buffer for top level input file */
struct parsefile *parsefile = &basepf; /* current input file */
char *pushedstring; /* copy of parsenextc when text pushed back */
int pushednleft; /* copy of parsenleft when text pushed back */
int init_editline = 0; /* editline library initialized? */
int whichprompt; /* 1 == PS1, 2 == PS2 */
EditLine *el; /* cookie for editline package */
#ifdef __STDC__
STATIC void pushfile(void);
#else
STATIC void pushfile();
#endif
#ifdef mkinit
INCLUDE "input.h"
INCLUDE "error.h"
INIT {
extern char basebuf[];
basepf.nextc = basepf.buf = basebuf;
}
RESET {
if (exception != EXSHELLPROC)
parsenleft = 0; /* clear input buffer */
popallfiles();
}
SHELLPROC {
popallfiles();
}
#endif
/*
* Read a line from the script.
*/
char *
pfgets(line, len)
char *line;
{
register 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() {
return pgetc_macro();
}
/*
* 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) Call read to read in the characters.
* 4) Delete all nul characters from the buffer.
*/
int
preadbuffer() {
register char *p, *q;
register int i;
register int something;
extern EditLine *el;
if (parsefile->strpush) {
popstring();
if (--parsenleft >= 0)
return (*parsenextc++);
}
if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
return PEOF;
flushout(&output);
flushout(&errout);
retry:
p = parsenextc = parsefile->buf;
if (parsefile->fd == 0 && el) {
const char *rl_cp;
int len;
rl_cp = el_gets(el, &len);
if (rl_cp == NULL) {
i = 0;
goto eof;
}
strcpy(p, rl_cp); /* XXX - BUFSIZE should redesign so not necessary */
i = len;
} else {
regular_read:
i = read(parsefile->fd, p, BUFSIZ - 1);
}
eof:
if (i <= 0) {
if (i < 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;
}
}
}
}
parsenleft = EOF_NLEFT;
return PEOF;
}
parsenleft = i - 1; /* we're returning one char in this call */
/* delete nul characters */
something = 0;
for (;;) {
if (*p == '\0')
break;
if (*p != ' ' && *p != '\t' && *p != '\n')
something = 1;
p++;
if (--i <= 0) {
*p = '\0';
goto done; /* no nul characters */
}
}
/*
* remove nuls
*/
q = p++;
while (--i > 0) {
if (*p != '\0')
*q++ = *p;
p++;
}
*q = '\0';
if (q == parsefile->buf)
goto retry; /* buffer contained nothing but nuls */
parsenleft = q - parsefile->buf - 1;
done:
if (parsefile->fd == 0 && hist && something) {
INTOFF;
history(hist, whichprompt == 1 ? H_ENTER : H_ADD,
parsefile->buf);
INTON;
}
if (vflag) {
/*
* This isn't right. Most shells coordinate it with
* reading a line at a time. I honestly don't know if its
* worth it.
*/
i = parsenleft + 1;
p = parsefile->buf;
for (; i--; p++)
out2c(*p)
flushout(out2);
}
return *parsenextc++;
}
/*
* Undo the last call to pgetc. Only one character may be pushed back.
* PEOF may be pushed back.
*/
void
pungetc() {
parsenleft++;
parsenextc--;
}
/*
* Push a string back onto the input at this current parsefile level.
* We handle aliases this way.
*/
void
pushstring(s, len, ap)
char *s;
int len;
void *ap;
{
struct strpush *sp;
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 = parsenextc;
sp->prevnleft = parsenleft;
sp->ap = (struct alias *)ap;
if (ap)
((struct alias *)ap)->flag |= ALIASINUSE;
parsenextc = s;
parsenleft = len;
INTON;
}
popstring()
{
struct strpush *sp = parsefile->strpush;
INTOFF;
parsenextc = sp->prevstring;
parsenleft = sp->prevnleft;
/*dprintf("*** 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(fname, push)
char *fname;
{
int fd;
int fd2;
INTOFF;
if ((fd = open(fname, O_RDONLY)) < 0)
error("Can't open %s", fname);
if (fd < 10) {
fd2 = copyfd(fd, 10);
close(fd);
if (fd2 < 0)
error("Out of file descriptors");
fd = fd2;
}
setinputfd(fd, push);
INTON;
}
/*
* Like setinputfile, but takes an open file descriptor. Call this with
* interrupts off.
*/
void
setinputfd(fd, push) {
if (push) {
pushfile();
parsefile->buf = ckmalloc(BUFSIZ);
}
if (parsefile->fd > 0)
close(parsefile->fd);
parsefile->fd = fd;
if (parsefile->buf == NULL)
parsefile->buf = ckmalloc(BUFSIZ);
parsenleft = 0;
plinno = 1;
}
/*
* Like setinputfile, but takes input from a string.
*/
void
setinputstring(string, push)
char *string;
{
INTOFF;
if (push)
pushfile();
parsenextc = string;
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() {
struct parsefile *pf;
parsefile->nleft = parsenleft;
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() {
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);
parsenleft = parsefile->nleft;
parsenextc = parsefile->nextc;
plinno = parsefile->linno;
INTON;
}
/*
* Return to top level.
*/
void
popallfiles() {
while (parsefile != &basepf)
popfile();
}
/*
* Close the file(s) that the shell is reading commands from. Called
* after a fork is done.
*/
void
closescript() {
popallfiles();
if (parsefile->fd > 0) {
close(parsefile->fd);
parsefile->fd = 0;
}
}