9b565c0250
If an alias's value ends with a space or tab, the next word is also checked for aliases. This is a POSIX feature. It is useful with utilities like command and nohup (alias them to themselves followed by a space).
551 lines
12 KiB
C
551 lines
12 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Kenneth Almquist.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95";
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#endif
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#endif /* not lint */
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stdio.h> /* defines BUFSIZ */
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#include <fcntl.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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/*
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* This file implements the input routines used by the parser.
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*/
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#include "shell.h"
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#include "redir.h"
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#include "syntax.h"
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#include "input.h"
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#include "output.h"
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#include "options.h"
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#include "memalloc.h"
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#include "error.h"
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#include "alias.h"
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#include "parser.h"
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#include "myhistedit.h"
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#include "trap.h"
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#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
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struct strpush {
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struct strpush *prev; /* preceding string on stack */
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const char *prevstring;
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int prevnleft;
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int prevlleft;
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struct alias *ap; /* if push was associated with an alias */
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};
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/*
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* The parsefile structure pointed to by the global variable parsefile
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* contains information about the current file being read.
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*/
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struct parsefile {
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struct parsefile *prev; /* preceding file on stack */
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int linno; /* current line */
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int fd; /* file descriptor (or -1 if string) */
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int nleft; /* number of chars left in this line */
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int lleft; /* number of lines left in this buffer */
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const char *nextc; /* next char in buffer */
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char *buf; /* input buffer */
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struct strpush *strpush; /* for pushing strings at this level */
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struct strpush basestrpush; /* so pushing one is fast */
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};
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int plinno = 1; /* input line number */
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int parsenleft; /* copy of parsefile->nleft */
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static int parselleft; /* copy of parsefile->lleft */
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const char *parsenextc; /* copy of parsefile->nextc */
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static char basebuf[BUFSIZ + 1];/* buffer for top level input file */
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static struct parsefile basepf = { /* top level input file */
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.nextc = basebuf,
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.buf = basebuf
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};
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static struct parsefile *parsefile = &basepf; /* current input file */
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int whichprompt; /* 1 == PS1, 2 == PS2 */
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EditLine *el; /* cookie for editline package */
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static void pushfile(void);
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static int preadfd(void);
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static void popstring(void);
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void
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resetinput(void)
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{
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popallfiles();
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parselleft = parsenleft = 0; /* clear input buffer */
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}
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/*
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* Read a line from the script.
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*/
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char *
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pfgets(char *line, int len)
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{
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char *p = line;
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int nleft = len;
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int c;
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while (--nleft > 0) {
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c = pgetc_macro();
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if (c == PEOF) {
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if (p == line)
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return NULL;
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break;
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}
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*p++ = c;
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if (c == '\n')
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break;
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}
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*p = '\0';
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return line;
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}
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/*
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* Read a character from the script, returning PEOF on end of file.
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* Nul characters in the input are silently discarded.
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*/
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int
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pgetc(void)
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{
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return pgetc_macro();
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}
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static int
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preadfd(void)
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{
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int nr;
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parsenextc = parsefile->buf;
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retry:
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#ifndef NO_HISTORY
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if (parsefile->fd == 0 && el) {
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static const char *rl_cp;
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static int el_len;
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if (rl_cp == NULL) {
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el_resize(el);
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rl_cp = el_gets(el, &el_len);
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}
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if (rl_cp == NULL)
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nr = el_len == 0 ? 0 : -1;
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else {
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nr = el_len;
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if (nr > BUFSIZ)
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nr = BUFSIZ;
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memcpy(parsefile->buf, rl_cp, nr);
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if (nr != el_len) {
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el_len -= nr;
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rl_cp += nr;
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} else
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rl_cp = NULL;
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}
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} else
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#endif
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nr = read(parsefile->fd, parsefile->buf, BUFSIZ);
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if (nr <= 0) {
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if (nr < 0) {
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if (errno == EINTR)
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goto retry;
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if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
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int flags = fcntl(0, F_GETFL, 0);
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if (flags >= 0 && flags & O_NONBLOCK) {
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flags &=~ O_NONBLOCK;
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if (fcntl(0, F_SETFL, flags) >= 0) {
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out2fmt_flush("sh: turning off NDELAY mode\n");
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goto retry;
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}
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}
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}
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}
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nr = -1;
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}
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return nr;
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}
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/*
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* Refill the input buffer and return the next input character:
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*
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* 1) If a string was pushed back on the input, pop it;
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* 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
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* from a string so we can't refill the buffer, return EOF.
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* 3) If there is more in this buffer, use it else call read to fill it.
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* 4) Process input up to the next newline, deleting nul characters.
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*/
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int
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preadbuffer(void)
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{
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char *p, *q;
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int more;
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char savec;
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while (parsefile->strpush) {
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/*
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* Add a space to the end of an alias to ensure that the
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* alias remains in use while parsing its last word.
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* This avoids alias recursions.
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*/
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if (parsenleft == -1 && parsefile->strpush->ap != NULL)
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return ' ';
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popstring();
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if (--parsenleft >= 0)
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return (*parsenextc++);
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}
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if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
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return PEOF;
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flushout(&output);
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flushout(&errout);
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again:
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if (parselleft <= 0) {
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if ((parselleft = preadfd()) == -1) {
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parselleft = parsenleft = EOF_NLEFT;
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return PEOF;
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}
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}
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q = p = parsefile->buf + (parsenextc - parsefile->buf);
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/* delete nul characters */
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for (more = 1; more;) {
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switch (*p) {
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case '\0':
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p++; /* Skip nul */
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goto check;
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case '\n':
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parsenleft = q - parsenextc;
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more = 0; /* Stop processing here */
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break;
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default:
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break;
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}
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*q++ = *p++;
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check:
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if (--parselleft <= 0) {
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parsenleft = q - parsenextc - 1;
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if (parsenleft < 0)
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goto again;
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*q = '\0';
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more = 0;
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}
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}
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savec = *q;
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*q = '\0';
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#ifndef NO_HISTORY
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if (parsefile->fd == 0 && hist &&
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parsenextc[strspn(parsenextc, " \t\n")] != '\0') {
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HistEvent he;
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INTOFF;
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history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
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parsenextc);
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INTON;
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}
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#endif
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if (vflag) {
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out2str(parsenextc);
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flushout(out2);
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}
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*q = savec;
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return *parsenextc++;
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}
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/*
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* Returns if we are certain we are at EOF. Does not cause any more input
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* to be read from the outside world.
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*/
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int
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preadateof(void)
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{
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if (parsenleft > 0)
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return 0;
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if (parsefile->strpush)
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return 0;
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if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
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return 1;
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return 0;
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}
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/*
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* Undo the last call to pgetc. Only one character may be pushed back.
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* PEOF may be pushed back.
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*/
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void
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pungetc(void)
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{
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parsenleft++;
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parsenextc--;
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}
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/*
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* Push a string back onto the input at this current parsefile level.
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* We handle aliases this way.
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*/
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void
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pushstring(char *s, int len, struct alias *ap)
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{
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struct strpush *sp;
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INTOFF;
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/*out2fmt_flush("*** calling pushstring: %s, %d\n", s, len);*/
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if (parsefile->strpush) {
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sp = ckmalloc(sizeof (struct strpush));
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sp->prev = parsefile->strpush;
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parsefile->strpush = sp;
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} else
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sp = parsefile->strpush = &(parsefile->basestrpush);
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sp->prevstring = parsenextc;
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sp->prevnleft = parsenleft;
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sp->prevlleft = parselleft;
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sp->ap = ap;
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if (ap)
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ap->flag |= ALIASINUSE;
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parsenextc = s;
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parsenleft = len;
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INTON;
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}
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static void
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popstring(void)
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{
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struct strpush *sp = parsefile->strpush;
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INTOFF;
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if (sp->ap) {
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if (parsenextc != sp->ap->val &&
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(parsenextc[-1] == ' ' || parsenextc[-1] == '\t'))
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forcealias();
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sp->ap->flag &= ~ALIASINUSE;
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}
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parsenextc = sp->prevstring;
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parsenleft = sp->prevnleft;
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parselleft = sp->prevlleft;
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/*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/
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parsefile->strpush = sp->prev;
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if (sp != &(parsefile->basestrpush))
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ckfree(sp);
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INTON;
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}
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/*
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* Set the input to take input from a file. If push is set, push the
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* old input onto the stack first.
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*/
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void
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setinputfile(const char *fname, int push)
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{
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int fd;
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int fd2;
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INTOFF;
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if ((fd = open(fname, O_RDONLY | O_CLOEXEC)) < 0)
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error("cannot open %s: %s", fname, strerror(errno));
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if (fd < 10) {
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fd2 = fcntl(fd, F_DUPFD_CLOEXEC, 10);
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close(fd);
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if (fd2 < 0)
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error("Out of file descriptors");
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fd = fd2;
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}
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setinputfd(fd, push);
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INTON;
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}
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/*
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* Like setinputfile, but takes an open file descriptor (which should have
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* its FD_CLOEXEC flag already set). Call this with interrupts off.
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*/
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void
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setinputfd(int fd, int push)
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{
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if (push) {
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pushfile();
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parsefile->buf = ckmalloc(BUFSIZ + 1);
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}
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if (parsefile->fd > 0)
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close(parsefile->fd);
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parsefile->fd = fd;
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if (parsefile->buf == NULL)
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parsefile->buf = ckmalloc(BUFSIZ + 1);
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parselleft = parsenleft = 0;
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plinno = 1;
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}
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/*
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* Like setinputfile, but takes input from a string.
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*/
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void
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setinputstring(const char *string, int push)
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{
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INTOFF;
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if (push)
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pushfile();
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parsenextc = string;
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parselleft = parsenleft = strlen(string);
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parsefile->buf = NULL;
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plinno = 1;
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INTON;
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}
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/*
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* To handle the "." command, a stack of input files is used. Pushfile
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* adds a new entry to the stack and popfile restores the previous level.
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*/
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static void
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pushfile(void)
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{
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struct parsefile *pf;
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parsefile->nleft = parsenleft;
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parsefile->lleft = parselleft;
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parsefile->nextc = parsenextc;
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parsefile->linno = plinno;
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pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
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pf->prev = parsefile;
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pf->fd = -1;
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pf->strpush = NULL;
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pf->basestrpush.prev = NULL;
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parsefile = pf;
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}
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void
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popfile(void)
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{
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struct parsefile *pf = parsefile;
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INTOFF;
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if (pf->fd >= 0)
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close(pf->fd);
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if (pf->buf)
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ckfree(pf->buf);
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while (pf->strpush)
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popstring();
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parsefile = pf->prev;
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ckfree(pf);
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parsenleft = parsefile->nleft;
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parselleft = parsefile->lleft;
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parsenextc = parsefile->nextc;
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plinno = parsefile->linno;
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INTON;
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}
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/*
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* Return current file (to go back to it later using popfilesupto()).
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*/
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struct parsefile *
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getcurrentfile(void)
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{
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return parsefile;
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}
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/*
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* Pop files until the given file is on top again. Useful for regular
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* builtins that read shell commands from files or strings.
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* If the given file is not an active file, an error is raised.
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*/
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void
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popfilesupto(struct parsefile *file)
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{
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while (parsefile != file && parsefile != &basepf)
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popfile();
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if (parsefile != file)
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error("popfilesupto() misused");
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}
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/*
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* Return to top level.
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*/
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void
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popallfiles(void)
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{
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while (parsefile != &basepf)
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popfile();
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}
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/*
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* Close the file(s) that the shell is reading commands from. Called
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* after a fork is done.
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*/
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void
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closescript(void)
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{
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popallfiles();
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if (parsefile->fd > 0) {
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close(parsefile->fd);
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parsefile->fd = 0;
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}
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}
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