/*- * Copyright (c) 1991 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 5.4 (Berkeley) 7/1/91"; #endif /* not lint */ /* * This file implements the input routines used by the parser. */ #include /* defines BUFSIZ */ #include "shell.h" #include #include #include "syntax.h" #include "input.h" #include "output.h" #include "memalloc.h" #include "error.h" #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ /* * The parsefile structure pointed to by the global variable parsefile * contains information about the current file being read. */ MKINIT struct parsefile { 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 */ struct parsefile *prev; /* preceding file on stack */ char *buf; /* input buffer */ }; 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 */ #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, switch back to the regular * buffer. * 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; if (pushedstring) { parsenextc = pushedstring; pushedstring = NULL; parsenleft = pushednleft; if (--parsenleft >= 0) return *parsenextc++; } if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) return PEOF; flushout(&output); flushout(&errout); retry: p = parsenextc = parsefile->buf; i = read(parsefile->fd, p, BUFSIZ); 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; /* delete nul characters */ for (;;) { if (*p++ == '\0') break; if (--i <= 0) return *parsenextc++; /* no nul characters */ } q = p - 1; while (--i > 0) { if (*p != '\0') *q++ = *p; p++; } if (q == parsefile->buf) goto retry; /* buffer contained nothing but nuls */ parsenleft = q - parsefile->buf - 1; 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. This code doesn't work if the user * tries to push back more than one string at once. */ void ppushback(string, length) char *string; { pushedstring = parsenextc; pushednleft = parsenleft; parsenextc = string; parsenleft = length; } /* * 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; parsefile = pf; } void popfile() { struct parsefile *pf = parsefile; INTOFF; if (pf->fd >= 0) close(pf->fd); if (pf->buf) ckfree(pf->buf); 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; } }