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32 * @(#)input.c 8.3 (Berkeley) 6/9/95
33 * $FreeBSD: head/bin/sh/input.c 245676 2013-01-19 22:12:08Z jilles $
36 #include <stdio.h> /* defines BUFSIZ */
44 * This file implements the input routines used by the parser.
57 #include "myhistedit.h"
60 #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
63 struct strpush *prev; /* preceding string on stack */
67 struct alias *ap; /* if push was associated with an alias */
71 * The parsefile structure pointed to by the global variable parsefile
72 * contains information about the current file being read.
76 struct parsefile *prev; /* preceding file on stack */
77 int linno; /* current line */
78 int fd; /* file descriptor (or -1 if string) */
79 int nleft; /* number of chars left in this line */
80 int lleft; /* number of lines left in this buffer */
81 char *nextc; /* next char in buffer */
82 char *buf; /* input buffer */
83 struct strpush *strpush; /* for pushing strings at this level */
84 struct strpush basestrpush; /* so pushing one is fast */
88 int plinno = 1; /* input line number */
89 int parsenleft; /* copy of parsefile->nleft */
90 MKINIT int parselleft; /* copy of parsefile->lleft */
91 char *parsenextc; /* copy of parsefile->nextc */
92 static char basebuf[BUFSIZ + 1];/* buffer for top level input file */
93 static struct parsefile basepf = { /* top level input file */
97 static struct parsefile *parsefile = &basepf; /* current input file */
98 int whichprompt; /* 1 == PS1, 2 == PS2 */
100 EditLine *el; /* cookie for editline package */
102 static void pushfile(void);
103 static int preadfd(void);
104 static void popstring(void);
113 parselleft = parsenleft = 0; /* clear input buffer */
119 * Read a line from the script.
123 pfgets(char *line, int len)
129 while (--nleft > 0) {
147 * Read a character from the script, returning PEOF on end of file.
148 * Nul characters in the input are silently discarded.
154 return pgetc_macro();
162 parsenextc = parsefile->buf;
165 if (el != NULL && gotwinch) {
172 if (parsefile->fd == 0 && el) {
173 static const char *rl_cp;
177 rl_cp = el_gets(el, &el_len);
179 nr = el_len == 0 ? 0 : -1;
184 memcpy(parsenextc, rl_cp, nr);
193 nr = read(parsefile->fd, parsenextc, BUFSIZ);
199 if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
200 int flags = fcntl(0, F_GETFL, 0);
201 if (flags >= 0 && flags & O_NONBLOCK) {
202 flags &=~ O_NONBLOCK;
203 if (fcntl(0, F_SETFL, flags) >= 0) {
204 out2fmt_flush("sh: turning off NDELAY mode\n");
216 * Refill the input buffer and return the next input character:
218 * 1) If a string was pushed back on the input, pop it;
219 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
220 * from a string so we can't refill the buffer, return EOF.
221 * 3) If there is more in this buffer, use it else call read to fill it.
222 * 4) Process input up to the next newline, deleting nul characters.
233 if (parsefile->strpush) {
235 if (--parsenleft >= 0)
236 return (*parsenextc++);
238 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
244 if (parselleft <= 0) {
245 if ((parselleft = preadfd()) == -1) {
246 parselleft = parsenleft = EOF_NLEFT;
253 /* delete nul characters */
255 for (more = 1; more;) {
266 parsenleft = q - parsenextc;
267 more = 0; /* Stop processing here */
277 if (--parselleft <= 0) {
278 parsenleft = q - parsenextc - 1;
290 if (parsefile->fd == 0 && hist && something) {
293 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
306 return *parsenextc++;
310 * Returns if we are certain we are at EOF. Does not cause any more input
311 * to be read from the outside world.
319 if (parsefile->strpush)
321 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
327 * Undo the last call to pgetc. Only one character may be pushed back.
328 * PEOF may be pushed back.
339 * Push a string back onto the input at this current parsefile level.
340 * We handle aliases this way.
343 pushstring(char *s, int len, struct alias *ap)
348 /*out2fmt_flush("*** calling pushstring: %s, %d\n", s, len);*/
349 if (parsefile->strpush) {
350 sp = ckmalloc(sizeof (struct strpush));
351 sp->prev = parsefile->strpush;
352 parsefile->strpush = sp;
354 sp = parsefile->strpush = &(parsefile->basestrpush);
355 sp->prevstring = parsenextc;
356 sp->prevnleft = parsenleft;
357 sp->prevlleft = parselleft;
360 ap->flag |= ALIASINUSE;
369 struct strpush *sp = parsefile->strpush;
372 parsenextc = sp->prevstring;
373 parsenleft = sp->prevnleft;
374 parselleft = sp->prevlleft;
375 /*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/
377 sp->ap->flag &= ~ALIASINUSE;
378 parsefile->strpush = sp->prev;
379 if (sp != &(parsefile->basestrpush))
385 * Set the input to take input from a file. If push is set, push the
386 * old input onto the stack first.
390 setinputfile(const char *fname, int push)
396 if ((fd = open(fname, O_RDONLY)) < 0)
397 error("cannot open %s: %s", fname, strerror(errno));
399 fd2 = fcntl(fd, F_DUPFD, 10);
402 error("Out of file descriptors");
405 setinputfd(fd, push);
411 * Like setinputfile, but takes an open file descriptor. Call this with
416 setinputfd(int fd, int push)
418 fcntl(fd, F_SETFD, FD_CLOEXEC);
421 parsefile->buf = ckmalloc(BUFSIZ + 1);
423 if (parsefile->fd > 0)
424 close(parsefile->fd);
426 if (parsefile->buf == NULL)
427 parsefile->buf = ckmalloc(BUFSIZ + 1);
428 parselleft = parsenleft = 0;
434 * Like setinputfile, but takes input from a string.
438 setinputstring(char *string, int push)
444 parselleft = parsenleft = strlen(string);
445 parsefile->buf = NULL;
453 * To handle the "." command, a stack of input files is used. Pushfile
454 * adds a new entry to the stack and popfile restores the previous level.
460 struct parsefile *pf;
462 parsefile->nleft = parsenleft;
463 parsefile->lleft = parselleft;
464 parsefile->nextc = parsenextc;
465 parsefile->linno = plinno;
466 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
467 pf->prev = parsefile;
470 pf->basestrpush.prev = NULL;
478 struct parsefile *pf = parsefile;
487 parsefile = pf->prev;
489 parsenleft = parsefile->nleft;
490 parselleft = parsefile->lleft;
491 parsenextc = parsefile->nextc;
492 plinno = parsefile->linno;
498 * Return current file (to go back to it later using popfilesupto()).
509 * Pop files until the given file is on top again. Useful for regular
510 * builtins that read shell commands from files or strings.
511 * If the given file is not an active file, an error is raised.
515 popfilesupto(struct parsefile *file)
517 while (parsefile != file && parsefile != &basepf)
519 if (parsefile != file)
520 error("popfilesupto() misused");
524 * Return to top level.
530 while (parsefile != &basepf)
537 * Close the file(s) that the shell is reading commands from. Called
538 * after a fork is done.
545 if (parsefile->fd > 0) {
546 close(parsefile->fd);