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Diffstat (limited to 'bin/1sh/input.c')
| -rw-r--r-- | bin/1sh/input.c | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/bin/1sh/input.c b/bin/1sh/input.c new file mode 100644 index 00000000..f2295a02 --- /dev/null +++ b/bin/1sh/input.c @@ -0,0 +1,518 @@ +/*- + * 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. + */ + +#ifndef lint +#if 0 +static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; +#endif +#endif /* not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD: releng/12.1/bin/sh/input.c 314436 2017-02-28 23:42:47Z imp $"); + +#include <stdio.h> /* defines BUFSIZ */ +#include <fcntl.h> +#include <errno.h> +#include <unistd.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 "trap.h" + +#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ + +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. + */ + +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 lines 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 */ +static int parselleft; /* copy of parsefile->lleft */ +const char *parsenextc; /* copy of parsefile->nextc */ +static char basebuf[BUFSIZ + 1];/* buffer for top level input file */ +static struct parsefile basepf = { /* top level input file */ + .nextc = basebuf, + .buf = basebuf +}; +static struct parsefile *parsefile = &basepf; /* current input file */ +int whichprompt; /* 1 == PS1, 2 == PS2 */ + +EditLine *el; /* cookie for editline package */ + +static void pushfile(void); +static int preadfd(void); +static void popstring(void); + +void +resetinput(void) +{ + popallfiles(); + parselleft = parsenleft = 0; /* clear input buffer */ +} + + + +/* + * 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; + parsenextc = parsefile->buf; + +retry: +#ifndef NO_HISTORY + if (parsefile->fd == 0 && el) { + static const char *rl_cp; + static int el_len; + + if (rl_cp == NULL) { + el_resize(el); + rl_cp = el_gets(el, &el_len); + } + if (rl_cp == NULL) + nr = el_len == 0 ? 0 : -1; + else { + nr = el_len; + if (nr > BUFSIZ) + nr = BUFSIZ; + memcpy(parsefile->buf, rl_cp, nr); + if (nr != el_len) { + el_len -= nr; + rl_cp += nr; + } else + rl_cp = NULL; + } + } else +#endif + nr = read(parsefile->fd, parsefile->buf, BUFSIZ); + + 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) { + out2fmt_flush("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 there is more 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, *r, *end; + char savec; + + while (parsefile->strpush) { + /* + * Add a space to the end of an alias to ensure that the + * alias remains in use while parsing its last word. + * This avoids alias recursions. + */ + if (parsenleft == -1 && parsefile->strpush->ap != NULL) + return ' '; + popstring(); + if (--parsenleft >= 0) + return (*parsenextc++); + } + if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) + return PEOF; + +again: + if (parselleft <= 0) { + if ((parselleft = preadfd()) == -1) { + parselleft = parsenleft = EOF_NLEFT; + return PEOF; + } + } + + p = parsefile->buf + (parsenextc - parsefile->buf); + end = p + parselleft; + *end = '\0'; + q = strchrnul(p, '\n'); + if (q != end && *q == '\0') { + /* delete nul characters */ + for (r = q; q != end; q++) { + if (*q != '\0') + *r++ = *q; + } + parselleft -= end - r; + if (parselleft == 0) + goto again; + end = p + parselleft; + *end = '\0'; + q = strchrnul(p, '\n'); + } + if (q == end) { + parsenleft = parselleft; + parselleft = 0; + } else /* *q == '\n' */ { + q++; + parsenleft = q - parsenextc; + parselleft -= parsenleft; + } + parsenleft--; + + savec = *q; + *q = '\0'; + +#ifndef NO_HISTORY + if (parsefile->fd == 0 && hist && + parsenextc[strspn(parsenextc, " \t\n")] != '\0') { + HistEvent he; + INTOFF; + history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD, + parsenextc); + INTON; + } +#endif + + if (vflag) { + out2str(parsenextc); + flushout(out2); + } + + *q = savec; + + return *parsenextc++; +} + +/* + * Returns if we are certain we are at EOF. Does not cause any more input + * to be read from the outside world. + */ + +int +preadateof(void) +{ + if (parsenleft > 0) + return 0; + if (parsefile->strpush) + return 0; + if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) + return 1; + return 0; +} + +/* + * 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; +/*out2fmt_flush("*** 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; +} + +static void +popstring(void) +{ + struct strpush *sp = parsefile->strpush; + + INTOFF; + if (sp->ap) { + if (parsenextc != sp->ap->val && + (parsenextc[-1] == ' ' || parsenextc[-1] == '\t')) + forcealias(); + sp->ap->flag &= ~ALIASINUSE; + } + parsenextc = sp->prevstring; + parsenleft = sp->prevnleft; + parselleft = sp->prevlleft; +/*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/ + 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) +{ + int fd; + int fd2; + + INTOFF; + if ((fd = open(fname, O_RDONLY | O_CLOEXEC)) < 0) + error("cannot open %s: %s", fname, strerror(errno)); + if (fd < 10) { + fd2 = fcntl(fd, F_DUPFD_CLOEXEC, 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 (which should have + * its FD_CLOEXEC flag already set). Call this with interrupts off. + */ + +void +setinputfd(int fd, int push) +{ + if (push) { + pushfile(); + parsefile->buf = ckmalloc(BUFSIZ + 1); + } + if (parsefile->fd > 0) + close(parsefile->fd); + parsefile->fd = fd; + if (parsefile->buf == NULL) + parsefile->buf = ckmalloc(BUFSIZ + 1); + parselleft = parsenleft = 0; + plinno = 1; +} + + +/* + * Like setinputfile, but takes input from a string. + */ + +void +setinputstring(const 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) + 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 current file (to go back to it later using popfilesupto()). + */ + +struct parsefile * +getcurrentfile(void) +{ + return parsefile; +} + + +/* + * Pop files until the given file is on top again. Useful for regular + * builtins that read shell commands from files or strings. + * If the given file is not an active file, an error is raised. + */ + +void +popfilesupto(struct parsefile *file) +{ + while (parsefile != file && parsefile != &basepf) + popfile(); + if (parsefile != file) + error("popfilesupto() misused"); +} + +/* + * 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. + */ + +void +closescript(void) +{ + popallfiles(); + if (parsefile->fd > 0) { + close(parsefile->fd); + parsefile->fd = 0; + } +} |