source: trunk/src/kash/input.c

/*      $NetBSD: input.c,v 1.39 2003/08/07 09:05:32 agc 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.
 */

#if 0
#ifndef lint
static char sccsid[] = "@(#)input.c     8.3 (Berkeley) 6/9/95";
#else
__RCSID("$NetBSD: input.c,v 1.39 2003/08/07 09:05:32 agc Exp $");
#endif /* not lint */
#endif

#include <stdio.h>      /* defines BUFSIZ */
#include <errno.h>
#include <stdlib.h>
#include <string.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"
#include "shinstance.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;
//      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 */
//      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 */
//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 */
//
//#ifndef SMALL
//EditLine *el;                 /* cookie for editline package */
//#endif

STATIC void pushfile(shinstance *psh);
static int preadfd(shinstance *psh);

#ifdef mkinit
INCLUDE <stdio.h>
INCLUDE "input.h"
INCLUDE "error.h"

INIT {
        psh->basepf.nextc = psh->basepf.buf = psh->basebuf;
}

RESET {
        if (psh->exception != EXSHELLPROC)
                psh->parselleft = psh->parsenleft = 0;  /* clear input buffer */
        popallfiles(psh);
}

SHELLPROC {
        popallfiles(psh);
}
#endif


/*
 * Read a line from the script.
 */

char *
pfgets(shinstance *psh, char *line, int len)
{
        char *p = line;
        int nleft = len;
        int c;

        while (--nleft > 0) {
                c = pgetc_macro(psh);
                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(shinstance *psh)
{
        return pgetc_macro(psh);
}


static int
preadfd_inner(shinstance *psh, char *buf, int bufsize)
{
        int nr;
retry:
#ifndef SMALL
        if (psh->parsefile->fd == 0 && psh->el) {
                static const char *rl_cp;
                static int el_len;

                if (rl_cp == NULL)
                        rl_cp = el_gets(psh->el, &el_len);
                if (rl_cp == NULL)
                        nr = 0;
                else {
                        nr = el_len;
                        if (nr > bufsize)
                                nr = bufsize;
                        memcpy(buf, rl_cp, nr);
                        if (nr != el_len) {
                                el_len -= nr;
                                rl_cp += nr;
                        } else
                                rl_cp = 0;
                }

        } else
#endif
                nr = shfile_read(&psh->fdtab, psh->parsefile->fd, buf, bufsize);


        if (nr <= 0) {
                if (nr < 0) {
                        if (errno == EINTR)
                                goto retry;
                        if (psh->parsefile->fd == 0 && errno == EWOULDBLOCK) {
                                int flags = shfile_fcntl(&psh->fdtab, 0, F_GETFL, 0);
                                if (flags >= 0 && flags & O_NONBLOCK) {
                                        flags &=~ O_NONBLOCK;
                                        if (shfile_fcntl(&psh->fdtab, 0, F_SETFL, flags) >= 0) {
                                                out2str(psh, "sh: turning off NDELAY mode\n");
                                                goto retry;
                                        }
                                }
                        }
                }
                nr = -1;
        }
        return nr;
}



static int
preadfd(shinstance *psh)
{
        int nr;
        char *buf = psh->parsefile->buf;
        psh->parsenextc = buf;

#ifdef SH_DEAL_WITH_CRLF
        /* Convert CRLF to LF. */
        nr = preadfd_inner(psh, buf, BUFSIZ - 9);
        if (nr > 0) {
                char *cr = memchr(buf, '\r', nr);
                while (cr) {
                        size_t left = nr - (cr - buf);

                        if (left > 1 && cr[1] == '\n') {
                                left--;
                                nr--;
                                memmove(cr, cr + 1, left);
                                cr = memchr(cr, '\r', left);
                        } else if (left == 1) {
                                /* Special case: \r at buffer end.  Read one more char. Screw \r\r\n sequences. */
                                int nr2 = preadfd_inner(psh, cr + 1, 1);
                                if (nr2 != 1) 
                                        break;
                                if (cr[1] == '\n') {
                                        *cr = '\n';
                                } else {
                                        nr++;
                                }
                                break;
                        } else {
                                cr = memchr(cr + 1, '\r', left);
                        }
                }
        }
#else
        nr = preadfd_inner(psh, buf, BUFSIZ - 8);
#endif
        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(shinstance *psh)
{
        char *p, *q;
        int more;
#ifndef SMALL
        int something;
#endif
        char savec;

        if (psh->parsefile->strpush) {
                popstring(psh);
                if (--psh->parsenleft >= 0)
                        return (*psh->parsenextc++);
        }
        if (psh->parsenleft == EOF_NLEFT || psh->parsefile->buf == NULL)
                return PEOF;
        flushout(&psh->output);
        flushout(&psh->errout);

again:
        if (psh->parselleft <= 0) {
                if ((psh->parselleft = preadfd(psh)) == -1) {
                        psh->parselleft = psh->parsenleft = EOF_NLEFT;
                        return PEOF;
                }
        }

        q = p = psh->parsenextc;

        /* 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':
                        psh->parsenleft = (int)(q - psh->parsenextc);
                        more = 0; /* Stop processing here */
                        break;

                default:
#ifndef SMALL
                        something = 1;
#endif
                        break;
                }

                *q++ = *p++;
check:
                if (--psh->parselleft <= 0) {
                        psh->parsenleft = (int)(q - psh->parsenextc - 1);
                        if (psh->parsenleft < 0)
                                goto again;
                        *q = '\0';
                        more = 0;
                }
        }

        savec = *q;
        *q = '\0';

#ifndef SMALL
        if (psh->parsefile->fd == 0 && hist && something) {
                HistEvent he;
                INTOFF;
                history(hist, &he, psh->whichprompt == 1? H_ENTER : H_APPEND,
                    psh->parsenextc);
                INTON;
        }
#endif

        if (vflag(psh)) {
                out2str(psh, psh->parsenextc);
                flushout(psh->out2);
        }

        *q = savec;

        return *psh->parsenextc++;
}

/*
 * Undo the last call to pgetc.  Only one character may be pushed back.
 * PEOF may be pushed back.
 */

void
pungetc(shinstance *psh)
{
        psh->parsenleft++;
        psh->parsenextc--;
}

/*
 * Push a string back onto the input at this current parsefile level.
 * We handle aliases this way.
 */
void
pushstring(shinstance *psh, char *s, size_t len, void *ap)
{
        struct strpush *sp;

        INTOFF;
/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
        if (psh->parsefile->strpush) {
                sp = ckmalloc(psh, sizeof (struct strpush));
                sp->prev = psh->parsefile->strpush;
                psh->parsefile->strpush = sp;
        } else
                sp = psh->parsefile->strpush = &(psh->parsefile->basestrpush);
        sp->prevstring = psh->parsenextc;
        sp->prevnleft = psh->parsenleft;
        sp->prevlleft = psh->parselleft;
        sp->ap = (struct alias *)ap;
        if (ap)
                ((struct alias *)ap)->flag |= ALIASINUSE;
        psh->parsenextc = s;
        psh->parsenleft = (int)len;
        INTON;
}

void
popstring(shinstance *psh)
{
        struct strpush *sp = psh->parsefile->strpush;

        INTOFF;
        psh->parsenextc = sp->prevstring;
        psh->parsenleft = sp->prevnleft;
        psh->parselleft = sp->prevlleft;
/*dprintf("*** calling popstring: restoring to '%s'\n", psh->parsenextc);*/
        if (sp->ap)
                sp->ap->flag &= ~ALIASINUSE;
        psh->parsefile->strpush = sp->prev;
        if (sp != &(psh->parsefile->basestrpush))
                ckfree(psh, 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(shinstance *psh, const char *fname, int push)
{
        int fd;
        int fd2;

        INTOFF;
/** @todo shfile fixme */
        if ((fd = shfile_open(&psh->fdtab, fname, O_RDONLY, 0)) < 0)
                error(psh, "Can't open %s", fname);
        if (fd < 10) {
                fd2 = movefd_above(psh, fd, 10);
                if (fd2 < 0)
                        error(psh, "Out of file descriptors");
                fd = fd2;
        }
        setinputfd(psh, fd, push);
        INTON;
}


/*
 * Like setinputfile, but takes an open file descriptor.  Call this with
 * interrupts off.
 */

void
setinputfd(shinstance *psh, int fd, int push)
{
        (void) shfile_cloexec(&psh->fdtab, fd, 1 /* close it */);
        if (push) {
                pushfile(psh);
                psh->parsefile->buf = ckmalloc(psh, BUFSIZ);
        }
        if (psh->parsefile->fd > 0)
                shfile_close(&psh->fdtab, psh->parsefile->fd);
        psh->parsefile->fd = fd;
        if (psh->parsefile->buf == NULL)
                psh->parsefile->buf = ckmalloc(psh, BUFSIZ);
        psh->parselleft = psh->parsenleft = 0;
        psh->plinno = 1;
}


/*
 * Like setinputfile, but takes input from a string.
 */

void
setinputstring(shinstance *psh, char *string, int push)
{
        INTOFF;
        if (push)
                pushfile(psh);
        psh->parsenextc = string;
        psh->parselleft = psh->parsenleft = (int)strlen(string);
        psh->parsefile->buf = NULL;
        psh->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(shinstance *psh)
{
        struct parsefile *pf;

        psh->parsefile->nleft = psh->parsenleft;
        psh->parsefile->lleft = psh->parselleft;
        psh->parsefile->nextc = psh->parsenextc;
        psh->parsefile->linno = psh->plinno;
        pf = (struct parsefile *)ckmalloc(psh, sizeof (struct parsefile));
        pf->prev = psh->parsefile;
        pf->fd = -1;
        pf->strpush = NULL;
        pf->basestrpush.prev = NULL;
        psh->parsefile = pf;
}


void
popfile(shinstance *psh)
{
        struct parsefile *pf = psh->parsefile;

        INTOFF;
        if (pf->fd >= 0)
                shfile_close(&psh->fdtab, pf->fd);
        if (pf->buf)
                ckfree(psh, pf->buf);
        while (pf->strpush)
                popstring(psh);
        psh->parsefile = pf->prev;
        ckfree(psh, pf);
        psh->parsenleft = psh->parsefile->nleft;
        psh->parselleft = psh->parsefile->lleft;
        psh->parsenextc = psh->parsefile->nextc;
        psh->plinno = psh->parsefile->linno;
        INTON;
}


/*
 * Return to top level.
 */

void
popallfiles(shinstance *psh)
{
        while (psh->parsefile != &psh->basepf)
                popfile(psh);
}



/*
 * 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(shinstance *psh)
{
        popallfiles(psh);
        if (psh->parsefile->fd > 0) {
                shfile_close(&psh->fdtab, psh->parsefile->fd);
                psh->parsefile->fd = 0;
        }
}