2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
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20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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35 static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95";
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <stdio.h> /* defines BUFSIZ */
49 * This file implements the input routines used by the parser.
63 #include "myhistedit.h"
67 #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
70 struct strpush *prev; /* preceding string on stack */
71 const char *prevstring;
74 struct alias *ap; /* if push was associated with an alias */
78 * The parsefile structure pointed to by the global variable parsefile
79 * contains information about the current file being read.
83 struct parsefile *prev; /* preceding file on stack */
84 int linno; /* current line */
85 int fd; /* file descriptor (or -1 if string) */
86 int nleft; /* number of chars left in this line */
87 int lleft; /* number of lines left in this buffer */
88 const char *nextc; /* next char in buffer */
89 char *buf; /* input buffer */
90 struct strpush *strpush; /* for pushing strings at this level */
91 struct strpush basestrpush; /* so pushing one is fast */
95 int plinno = 1; /* input line number */
96 int parsenleft; /* copy of parsefile->nleft */
97 static int parselleft; /* copy of parsefile->lleft */
98 const char *parsenextc; /* copy of parsefile->nextc */
99 static char basebuf[BUFSIZ + 1];/* buffer for top level input file */
100 static struct parsefile basepf = { /* top level input file */
104 static struct parsefile *parsefile = &basepf; /* current input file */
105 int whichprompt; /* 1 == PS1, 2 == PS2 */
108 EditLine *el; /* cookie for editline package */
111 static void pushfile(void);
112 static int preadfd(void);
113 static void popstring(void);
119 parselleft = parsenleft = 0; /* clear input buffer */
125 * Read a character from the script, returning PEOF on end of file.
126 * Nul characters in the input are silently discarded.
132 return pgetc_macro();
140 parsenextc = parsefile->buf;
144 if (parsefile->fd == 0 && el) {
145 static const char *rl_cp;
150 rl_cp = el_gets(el, &el_len);
153 nr = el_len == 0 ? 0 : -1;
158 memcpy(parsefile->buf, rl_cp, nr);
167 nr = read(parsefile->fd, parsefile->buf, BUFSIZ);
173 if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
174 int flags = fcntl(0, F_GETFL, 0);
175 if (flags >= 0 && flags & O_NONBLOCK) {
176 flags &=~ O_NONBLOCK;
177 if (fcntl(0, F_SETFL, flags) >= 0) {
178 out2fmt_flush("sh: turning off NDELAY mode\n");
190 * Refill the input buffer and return the next input character:
192 * 1) If a string was pushed back on the input, pop it;
193 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
194 * from a string so we can't refill the buffer, return EOF.
195 * 3) If there is more in this buffer, use it else call read to fill it.
196 * 4) Process input up to the next newline, deleting nul characters.
206 while (parsefile->strpush) {
208 * Add a space to the end of an alias to ensure that the
209 * alias remains in use while parsing its last word.
210 * This avoids alias recursions.
212 if (parsenleft == -1 && parsefile->strpush->ap != NULL)
215 if (--parsenleft >= 0)
216 return (*parsenextc++);
218 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
224 if (parselleft <= 0) {
225 if ((parselleft = preadfd()) == -1) {
226 parselleft = parsenleft = EOF_NLEFT;
231 q = p = parsefile->buf + (parsenextc - parsefile->buf);
233 /* delete nul characters */
234 for (more = 1; more;) {
241 parsenleft = q - parsenextc;
242 more = 0; /* Stop processing here */
251 if (--parselleft <= 0) {
252 parsenleft = q - parsenextc - 1;
264 if (parsefile->fd == 0 && hist &&
265 parsenextc[strspn(parsenextc, " \t\n")] != '\0') {
268 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
281 return *parsenextc++;
285 * Returns if we are certain we are at EOF. Does not cause any more input
286 * to be read from the outside world.
294 if (parsefile->strpush)
296 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
302 * Undo the last call to pgetc. Only one character may be pushed back.
303 * PEOF may be pushed back.
314 * Push a string back onto the input at this current parsefile level.
315 * We handle aliases this way.
318 pushstring(const char *s, int len, struct alias *ap)
323 /*out2fmt_flush("*** calling pushstring: %s, %d\n", s, len);*/
324 if (parsefile->strpush) {
325 sp = ckmalloc(sizeof (struct strpush));
326 sp->prev = parsefile->strpush;
327 parsefile->strpush = sp;
329 sp = parsefile->strpush = &(parsefile->basestrpush);
330 sp->prevstring = parsenextc;
331 sp->prevnleft = parsenleft;
332 sp->prevlleft = parselleft;
335 ap->flag |= ALIASINUSE;
344 struct strpush *sp = parsefile->strpush;
348 if (parsenextc != sp->ap->val &&
349 (parsenextc[-1] == ' ' || parsenextc[-1] == '\t'))
351 sp->ap->flag &= ~ALIASINUSE;
353 parsenextc = sp->prevstring;
354 parsenleft = sp->prevnleft;
355 parselleft = sp->prevlleft;
356 /*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/
357 parsefile->strpush = sp->prev;
358 if (sp != &(parsefile->basestrpush))
364 * Set the input to take input from a file. If push is set, push the
365 * old input onto the stack first.
369 setinputfile(const char *fname, int push)
375 if ((fd = open(fname, O_RDONLY | O_CLOEXEC_MAYBE)) < 0)
376 error("cannot open %s: %s", fname, strerror(errno));
378 fd2 = fcntl(fd, F_DUPFD_CLOEXEC_MAYBE, 10);
381 error("Out of file descriptors");
384 setinputfd(fd, push);
390 * Like setinputfile, but takes an open file descriptor (which should have
391 * its FD_CLOEXEC flag already set). Call this with interrupts off.
395 setinputfd(int fd, int push)
397 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC)
398 fcntl(fd, F_SETFD, FD_CLOEXEC);
402 parsefile->buf = ckmalloc(BUFSIZ + 1);
404 if (parsefile->fd > 0)
405 close(parsefile->fd);
407 if (parsefile->buf == NULL)
408 parsefile->buf = ckmalloc(BUFSIZ + 1);
409 parselleft = parsenleft = 0;
415 * Like setinputfile, but takes input from a string.
419 setinputstring(const char *string, int push)
425 parselleft = parsenleft = strlen(string);
426 parsefile->buf = NULL;
434 * To handle the "." command, a stack of input files is used. Pushfile
435 * adds a new entry to the stack and popfile restores the previous level.
441 struct parsefile *pf;
443 parsefile->nleft = parsenleft;
444 parsefile->lleft = parselleft;
445 parsefile->nextc = parsenextc;
446 parsefile->linno = plinno;
447 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
448 pf->prev = parsefile;
451 pf->basestrpush.prev = NULL;
459 struct parsefile *pf = parsefile;
468 parsefile = pf->prev;
470 parsenleft = parsefile->nleft;
471 parselleft = parsefile->lleft;
472 parsenextc = parsefile->nextc;
473 plinno = parsefile->linno;
479 * Return current file (to go back to it later using popfilesupto()).
490 * Pop files until the given file is on top again. Useful for regular
491 * builtins that read shell commands from files or strings.
492 * If the given file is not an active file, an error is raised.
496 popfilesupto(struct parsefile *file)
498 while (parsefile != file && parsefile != &basepf)
500 if (parsefile != file)
501 error("popfilesupto() misused");
505 * Return to top level.
511 while (parsefile != &basepf)
518 * Close the file(s) that the shell is reading commands from. Called
519 * after a fork is done.
526 if (parsefile->fd > 0) {
527 close(parsefile->fd);