2 * Copyright (c) 1992, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 * Keith Bostic. All rights reserved.
7 * See the LICENSE file for redistribution information.
13 static const char sccsid[] = "$Id: exf.c,v 10.64 2015/04/05 15:21:55 zy Exp $";
16 #include <sys/types.h>
17 #include <sys/queue.h>
22 * We include <sys/file.h>, because the flock(2) and open(2) #defines
23 * were found there on historical systems. We also include <fcntl.h>
24 * because the open(2) #defines are found there on newer systems.
28 #include <bitstring.h>
40 static int file_backup(SCR *, char *, char *);
41 static void file_cinit(SCR *);
42 static void file_encinit(SCR *);
43 static void file_comment(SCR *);
44 static int file_spath(SCR *, FREF *, struct stat *, int *);
48 * Insert a file name into the FREF list, if it doesn't already
52 * The "if it doesn't already appear" changes vi's semantics slightly. If
53 * you do a "vi foo bar", and then execute "next bar baz", the edit of bar
54 * will reflect the line/column of the previous edit session. Historic nvi
55 * did not do this. The change is a logical extension of the change where
56 * vi now remembers the last location in any file that it has ever edited,
57 * not just the previously edited file.
59 * PUBLIC: FREF *file_add(SCR *, char *);
70 * Return it if it already exists. Note that we test against the
71 * user's name, whatever that happens to be, including if it's a
74 * If the user added a file but was unable to initialize it, there
75 * can be file list entries where the name field is NULL. Discard
76 * them the next time we see them.
80 TAILQ_FOREACH_SAFE(frp, gp->frefq, q, tfrp) {
81 if (frp->name == NULL) {
82 TAILQ_REMOVE(gp->frefq, frp, q);
83 if (frp->name != NULL)
88 if (!strcmp(frp->name, name))
92 /* Allocate and initialize the FREF structure. */
93 CALLOC(sp, frp, FREF *, 1, sizeof(FREF));
98 * If no file name specified, or if the file name is a request
99 * for something temporary, file_init() will allocate the file
100 * name. Temporary files are always ignored.
102 if (name != NULL && strcmp(name, TEMPORARY_FILE_STRING) &&
103 (frp->name = strdup(name)) == NULL) {
105 msgq(sp, M_SYSERR, NULL);
109 /* Append into the chain of file names. */
110 TAILQ_INSERT_TAIL(gp->frefq, frp, q);
117 * Start editing a file, based on the FREF structure. If successsful,
118 * let go of any previous file. Don't release the previous file until
119 * absolutely sure we have the new one.
121 * PUBLIC: int file_init(SCR *, FREF *, char *, int);
131 RECNOINFO oinfo = { 0 };
134 int fd, exists, open_err, readonly;
137 open_err = readonly = 0;
140 * If the file is a recovery file, let the recovery code handle it.
141 * Clear the FR_RECOVER flag first -- the recovery code does set up,
142 * and then calls us! If the recovery call fails, it's probably
143 * because the named file doesn't exist. So, move boldly forward,
144 * presuming that there's an error message the user will get to see.
146 if (F_ISSET(frp, FR_RECOVER)) {
147 F_CLR(frp, FR_RECOVER);
148 return (rcv_read(sp, frp));
152 * Required FRP initialization; the only flag we keep is the
153 * cursor information.
155 F_CLR(frp, ~FR_CURSORSET);
158 * Required EXF initialization:
159 * Flush the line caches.
160 * Default recover mail file fd to -1.
161 * Set initial EXF flag bits.
163 CALLOC_RET(sp, ep, EXF *, 1, sizeof(EXF));
164 ep->c_lno = ep->c_nlines = OOBLNO;
166 F_SET(ep, F_FIRSTMODIFY);
169 * Scan the user's path to find the file that we're going to
172 if (file_spath(sp, frp, &sb, &exists))
176 * If no name or backing file, for whatever reason, create a backing
177 * temporary file, saving the temp file name so we can later unlink
178 * it. If the user never named this file, copy the temporary file name
179 * to the real name (we display that until the user renames it).
182 if (LF_ISSET(FS_OPENERR) || oname == NULL || !exists) {
185 if (opts_empty(sp, O_TMPDIR, 0))
188 join(O_STR(sp, O_TMPDIR), "vi.XXXXXXXXXX")) == NULL) {
189 msgq(sp, M_SYSERR, NULL);
192 if ((fd = mkstemp(tname)) == -1 || fstat(fd, &sb)) {
195 "237|Unable to create temporary file");
201 if (frp->name == NULL) {
202 F_SET(frp, FR_TMPFILE);
203 if ((frp->name = strdup(tname)) == NULL) {
204 msgq(sp, M_SYSERR, NULL);
210 if (!LF_ISSET(FS_OPENERR))
211 F_SET(frp, FR_NEWFILE);
213 ep->mtim = sb.st_mtimespec;
217 * A seat of the pants calculation: try to keep the file in
218 * 15 pages or less. Don't use a page size larger than 16K
219 * (vi should have good locality) or smaller than 1K.
221 psize = ((sb.st_size / 15) + 1023) / 1024;
226 psize = p2roundup(psize) << 10;
229 ep->mdev = sb.st_dev;
230 ep->minode = sb.st_ino;
232 ep->mtim = sb.st_mtimespec;
234 if (!S_ISREG(sb.st_mode))
235 msgq_str(sp, M_ERR, oname,
236 "238|Warning: %s is not a regular file");
239 /* Set up recovery. */
240 oinfo.bval = '\n'; /* Always set. */
242 oinfo.flags = F_ISSET(sp->gp, G_SNAPSHOT) ? R_SNAPSHOT : 0;
243 if (rcv_name == NULL) {
244 if (!rcv_tmp(sp, ep, frp->name))
245 oinfo.bfname = ep->rcv_path;
247 if ((ep->rcv_path = strdup(rcv_name)) == NULL) {
248 msgq(sp, M_SYSERR, NULL);
251 oinfo.bfname = ep->rcv_path;
252 F_SET(ep, F_MODIFIED);
255 /* Open a db structure. */
256 if ((ep->db = dbopen(rcv_name == NULL ? oname : NULL,
257 O_NONBLOCK | O_RDONLY,
258 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH,
259 DB_RECNO, &oinfo)) == NULL) {
261 M_SYSERR, rcv_name == NULL ? oname : rcv_name, "%s");
262 if (F_ISSET(frp, FR_NEWFILE))
266 * Historically, vi permitted users to edit files that couldn't
267 * be read. This isn't useful for single files from a command
268 * line, but it's quite useful for "vi *.c", since you can skip
269 * past files that you can't read.
276 * Do the remaining things that can cause failure of the new file,
277 * mark and logging initialization.
279 if (mark_init(sp, ep) || log_init(sp, ep))
283 * Set the alternate file name to be the file we're discarding.
286 * Temporary files can't become alternate files, so there's no file
287 * name. This matches historical practice, although it could only
288 * happen in historical vi as the result of the initial command, i.e.
289 * if vi was executed without a file name.
291 if (LF_ISSET(FS_SETALT))
292 set_alt_name(sp, sp->frp == NULL ||
293 F_ISSET(sp->frp, FR_TMPFILE) ? NULL : sp->frp->name);
296 * Close the previous file; if that fails, close the new one and run
300 * There's a nasty special case. If the user edits a temporary file,
301 * and then does an ":e! %", we need to re-initialize the backing
302 * file, but we can't change the name. (It's worse -- we're dealing
303 * with *names* here, we can't even detect that it happened.) Set a
304 * flag so that the file_end routine ignores the backing information
305 * of the old file if it happens to be the same as the new one.
308 * Side-effect: after the call to file_end(), sp->frp may be NULL.
310 if (sp->ep != NULL) {
311 F_SET(frp, FR_DONTDELETE);
312 if (file_end(sp, NULL, LF_ISSET(FS_FORCE))) {
313 (void)file_end(sp, ep, 1);
316 F_CLR(frp, FR_DONTDELETE);
320 * Lock the file; if it's a recovery file, it should already be
321 * locked. Note, we acquire the lock after the previous file
322 * has been ended, so that we don't get an "already locked" error
326 * While the user can't interrupt us between the open and here,
327 * there's a race between the dbopen() and the lock. Not much
328 * we can do about it.
331 * We don't make a big deal of not being able to lock the file. As
332 * locking rarely works over NFS, and often fails if the file was
333 * mmap(2)'d, it's far too common to do anything like print an error
334 * message, let alone make the file readonly. At some future time,
335 * when locking is a little more reliable, this should change to be
338 if (rcv_name == NULL)
339 switch (file_lock(sp, oname, ep->db->fd(ep->db), 0)) {
341 F_SET(frp, FR_UNLOCKED);
345 if (F_ISSET(sp, SC_READONLY))
347 msgq_str(sp, M_INFO, oname,
348 "239|%s already locked, session is read-only");
355 * Historically, the readonly edit option was set per edit buffer in
356 * vi, unless the -R command-line option was specified or the program
357 * was executed as "view". (Well, to be truthful, if the letter 'w'
358 * occurred anywhere in the program name, but let's not get into that.)
359 * So, the persistant readonly state has to be stored in the screen
360 * structure, and the edit option value toggles with the contents of
361 * the edit buffer. If the persistant readonly flag is set, set the
362 * readonly edit option.
364 * Otherwise, try and figure out if a file is readonly. This is a
365 * dangerous thing to do. The kernel is the only arbiter of whether
366 * or not a file is writeable, and the best that a user program can
367 * do is guess. Obvious loopholes are files that are on a file system
368 * mounted readonly (access catches this one on a few systems), or
369 * alternate protection mechanisms, ACL's for example, that we can't
370 * portably check. Lots of fun, and only here because users whined.
373 * Historic vi displayed the readonly message if none of the file
374 * write bits were set, or if an an access(2) call on the path
375 * failed. This seems reasonable. If the file is mode 444, root
376 * users may want to know that the owner of the file did not expect
379 * Historic vi set the readonly bit if no write bits were set for
380 * a file, even if the access call would have succeeded. This makes
381 * the superuser force the write even when vi expects that it will
382 * succeed. I'm less supportive of this semantic, but it's historic
383 * practice and the conservative approach to vi'ing files as root.
385 * It would be nice if there was some way to update this when the user
386 * does a "^Z; chmod ...". The problem is that we'd first have to
387 * distinguish between readonly bits set because of file permissions
388 * and those set for other reasons. That's not too hard, but deciding
389 * when to reevaluate the permissions is trickier. An alternative
390 * might be to turn off the readonly bit if the user forces a write
394 * Access(2) doesn't consider the effective uid/gid values. This
395 * probably isn't a problem for vi when it's running standalone.
397 if (readonly || F_ISSET(sp, SC_READONLY) ||
398 (!F_ISSET(frp, FR_NEWFILE) &&
399 (!(sb.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH)) ||
400 access(frp->name, W_OK))))
401 O_SET(sp, O_READONLY);
403 O_CLR(sp, O_READONLY);
410 /* Detect and set the file encoding */
413 /* Set the initial cursor position, queue initial command. */
416 /* Redraw the screen from scratch, schedule a welcome message. */
417 F_SET(sp, SC_SCR_REFORMAT | SC_STATUS);
421 err: if (frp->name != NULL) {
425 if (frp->tname != NULL) {
426 (void)unlink(frp->tname);
431 oerr: if (F_ISSET(ep, F_RCV_ON))
432 (void)unlink(ep->rcv_path);
433 if (ep->rcv_path != NULL) {
438 (void)ep->db->close(ep->db);
442 file_init(sp, frp, rcv_name, flags | FS_OPENERR) : 1);
447 * Scan the user's path to find the file that we're going to
460 char *name, *p, *t, *path;
463 * If the name is NULL or an explicit reference (i.e., the first
464 * component is . or ..) ignore the O_PATH option.
471 if (name[0] == '/' || (name[0] == '.' &&
472 (name[1] == '/' || (name[1] == '.' && name[2] == '/')))) {
473 *existsp = !stat(name, sbp);
478 if (!stat(name, sbp)) {
483 /* Try the O_PATH option values. */
484 for (found = 0, p = t = O_STR(sp, O_PATH);; ++p)
485 if (*p == ':' || *p == '\0') {
487 * Ignore the empty strings and ".", since we've already
488 * tried the current directory.
490 if (t < p && (p - t != 1 || *t != '.')) {
493 if ((path = join(t, name)) == NULL) {
494 msgq(sp, M_SYSERR, NULL);
499 if (!stat(path, sbp)) {
510 /* If we found it, build a new pathname and discard the old one. */
521 * Set up the initial cursor position.
533 /* Set some basic defaults. */
538 * Historically, initial commands (the -c option) weren't executed
539 * until a file was loaded, e.g. "vi +10 nofile", followed by an
540 * :edit or :tag command, would execute the +10 on the file loaded
541 * by the subsequent command, (assuming that it existed). This
542 * applied as well to files loaded using the tag commands, and we
543 * follow that historic practice. Also, all initial commands were
544 * ex commands and were always executed on the last line of the file.
546 * Otherwise, if no initial command for this file:
547 * If in ex mode, move to the last line, first nonblank character.
548 * If the file has previously been edited, move to the last known
549 * position, and check it for validity.
550 * Otherwise, move to the first line, first nonblank.
552 * This gets called by the file init code, because we may be in a
553 * file of ex commands and we want to execute them from the right
554 * location in the file.
558 if (gp->c_option != NULL && !F_ISSET(sp->frp, FR_NEWFILE)) {
559 if (db_last(sp, &sp->lno))
565 CHAR2INT(sp, gp->c_option, strlen(gp->c_option) + 1,
567 if (ex_run_str(sp, "-c option", wp, wlen - 1, 1, 1))
570 } else if (F_ISSET(sp, SC_EX)) {
571 if (db_last(sp, &sp->lno))
580 if (F_ISSET(sp->frp, FR_CURSORSET)) {
581 sp->lno = sp->frp->lno;
582 sp->cno = sp->frp->cno;
584 /* If returning to a file in vi, center the line. */
585 F_SET(sp, SC_SCR_CENTER);
587 if (O_ISSET(sp, O_COMMENT))
593 if (db_get(sp, sp->lno, 0, NULL, &len)) {
598 if (!nb && sp->cno > len)
603 (void)nonblank(sp, sp->lno, &sp->cno);
608 * The initial column is also the most attractive column.
614 * Historically, vi initialized the absolute mark, but ex did not.
615 * Which meant, that if the first command in ex mode was "visual",
616 * or if an ex command was executed first (e.g. vi +10 file) vi was
617 * entered without the mark being initialized. For consistency, if
618 * the file isn't empty, we initialize it for everyone, believing
619 * that it can't hurt, and is generally useful. Not initializing it
620 * if the file is empty is historic practice, although it has always
621 * been possible to set (and use) marks in empty vi files.
625 (void)mark_set(sp, ABSMARK1, &m, 0);
630 * Stop editing a file.
632 * PUBLIC: int file_end(SCR *, EXF *, int);
644 * ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
645 * (If argument ep is NULL, use sp->ep.)
647 * If multiply referenced, just decrement the count and return.
651 if (--ep->refcnt != 0)
656 * Clean up the FREF structure.
658 * Save the cursor location.
661 * It would be cleaner to do this somewhere else, but by the time
662 * ex or vi knows that we're changing files it's already happened.
667 F_SET(frp, FR_CURSORSET);
670 * We may no longer need the temporary backing file, so clean it
671 * up. We don't need the FREF structure either, if the file was
672 * never named, so lose it.
675 * Re: FR_DONTDELETE, see the comment above in file_init().
677 if (!F_ISSET(frp, FR_DONTDELETE) && frp->tname != NULL) {
678 if (unlink(frp->tname))
679 msgq_str(sp, M_SYSERR, frp->tname, "240|%s: remove");
682 if (F_ISSET(frp, FR_TMPFILE)) {
683 TAILQ_REMOVE(sp->gp->frefq, frp, q);
684 if (frp->name != NULL)
692 * Clean up the EXF structure.
694 * Close the db structure.
696 if (ep->db->close != NULL && ep->db->close(ep->db) && !force) {
697 msgq_str(sp, M_SYSERR, frp->name, "241|%s: close");
702 /* COMMITTED TO THE CLOSE. THERE'S NO GOING BACK... */
705 (void)log_end(sp, ep);
707 /* Free up any marks. */
708 (void)mark_end(sp, ep);
711 * Delete recovery files, close the open descriptor, free recovery
712 * memory. See recover.c for a description of the protocol.
715 * Unlink backup file first, we can detect that the recovery file
716 * doesn't reference anything when the user tries to recover it.
717 * There's a race, here, obviously, but it's fairly small.
719 if (!F_ISSET(ep, F_RCV_NORM)) {
720 if (ep->rcv_path != NULL && unlink(ep->rcv_path))
721 msgq_str(sp, M_SYSERR, ep->rcv_path, "242|%s: remove");
722 if (ep->rcv_mpath != NULL && unlink(ep->rcv_mpath))
723 msgq_str(sp, M_SYSERR, ep->rcv_mpath, "243|%s: remove");
725 if (ep->rcv_fd != -1)
726 (void)close(ep->rcv_fd);
727 if (ep->rcv_path != NULL)
729 if (ep->rcv_mpath != NULL)
740 * Write the file to disk. Historic vi had fairly convoluted
741 * semantics for whether or not writes would happen. That's
744 * PUBLIC: int file_write(SCR *, MARK *, MARK *, char *, int);
754 enum { NEWFILE, OLDFILE } mtype;
762 int fd, nf, noname, oflags, rval;
763 char *p, *s, *t, buf[1024];
770 * Writing '%', or naming the current file explicitly, has the
771 * same semantics as writing without a name.
773 if (name == NULL || !strcmp(name, frp->name)) {
779 /* Can't write files marked read-only, unless forced. */
780 if (!LF_ISSET(FS_FORCE) && noname && O_ISSET(sp, O_READONLY)) {
781 msgq(sp, M_ERR, LF_ISSET(FS_POSSIBLE) ?
782 "244|Read-only file, not written; use ! to override" :
783 "245|Read-only file, not written");
787 /* If not forced, not appending, and "writeany" not set ... */
788 if (!LF_ISSET(FS_FORCE | FS_APPEND) && !O_ISSET(sp, O_WRITEANY)) {
789 /* Don't overwrite anything but the original file. */
790 if ((!noname || F_ISSET(frp, FR_NAMECHANGE)) &&
792 msgq_str(sp, M_ERR, name,
793 LF_ISSET(FS_POSSIBLE) ?
794 "246|%s exists, not written; use ! to override" :
795 "247|%s exists, not written");
800 * Don't write part of any existing file. Only test for the
801 * original file, the previous test catches anything else.
803 if (!LF_ISSET(FS_ALL) && noname && !stat(name, &sb)) {
804 msgq(sp, M_ERR, LF_ISSET(FS_POSSIBLE) ?
805 "248|Partial file, not written; use ! to override" :
806 "249|Partial file, not written");
812 * Figure out if the file already exists -- if it doesn't, we display
813 * the "new file" message. The stat might not be necessary, but we
814 * just repeat it because it's easier than hacking the previous tests.
815 * The information is only used for the user message and modification
816 * time test, so we can ignore the obvious race condition.
818 * One final test. If we're not forcing or appending the current file,
819 * and we have a saved modification time, object if the file changed
820 * since we last edited or wrote it, and make them force it.
825 if (noname && !LF_ISSET(FS_FORCE | FS_APPEND) &&
826 ((F_ISSET(ep, F_DEVSET) &&
827 (sb.st_dev != ep->mdev || sb.st_ino != ep->minode)) ||
828 timespeccmp(&sb.st_mtimespec, &ep->mtim, !=))) {
829 msgq_str(sp, M_ERR, name, LF_ISSET(FS_POSSIBLE) ?
830 "250|%s: file modified more recently than this copy; use ! to override" :
831 "251|%s: file modified more recently than this copy");
838 /* Set flags to create, write, and either append or truncate. */
839 oflags = O_CREAT | O_WRONLY |
840 (LF_ISSET(FS_APPEND) ? O_APPEND : O_TRUNC);
842 /* Backup the file if requested. */
843 if (!opts_empty(sp, O_BACKUP, 1) &&
844 file_backup(sp, name, O_STR(sp, O_BACKUP)) && !LF_ISSET(FS_FORCE))
848 if ((fd = open(name, oflags,
849 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)) < 0) {
850 if (errno == EACCES && LF_ISSET(FS_FORCE)) {
852 * If the user owns the file but does not
853 * have write permission on it, grant it
854 * automatically for the duration of the
855 * opening of the file, if possible.
860 if (stat(name, &sb) != 0)
863 if (!(sb.st_mode & S_IWUSR) && sb.st_uid == getuid())
867 if (chmod(name, fmode) != 0)
869 fd = open(name, oflags, S_IRUSR | S_IWUSR |
870 S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
873 (void)fchmod(fd, sb.st_mode);
878 msgq_str(sp, M_SYSERR, name, "%s");
883 /* Try and get a lock. */
884 if (!noname && file_lock(sp, NULL, fd, 0) == LOCK_UNAVAIL)
885 msgq_str(sp, M_ERR, name,
886 "252|%s: write lock was unavailable");
889 * Use stdio for buffering.
892 * SVR4.2 requires the fdopen mode exactly match the original open
893 * mode, i.e. you have to open with "a" if appending.
895 if ((fp = fdopen(fd, LF_ISSET(FS_APPEND) ? "a" : "w")) == NULL) {
896 msgq_str(sp, M_SYSERR, name, "%s");
901 /* Build fake addresses, if necessary. */
906 if (db_last(sp, &to.lno))
912 rval = ex_writefp(sp, name, fp, fm, tm, &nlno, &nch, 0);
915 * Save the new last modification time -- even if the write fails
916 * we re-init the time. That way the user can clean up the disk
917 * and rewrite without having to force it.
921 timepoint_system(&ep->mtim);
924 ep->mdev = sb.st_dev;
925 ep->minode = sb.st_ino;
927 ep->mtim = sb.st_mtimespec;
931 * If the write failed, complain loudly. ex_writefp() has already
932 * complained about the actual error, reinforce it if data was lost.
935 if (!LF_ISSET(FS_APPEND))
936 msgq_str(sp, M_ERR, name,
937 "254|%s: WARNING: FILE TRUNCATED");
942 * Once we've actually written the file, it doesn't matter that the
943 * file name was changed -- if it was, we've already whacked it.
945 F_CLR(frp, FR_NAMECHANGE);
948 * If wrote the entire file, and it wasn't by appending it to a file,
949 * clear the modified bit. If the file was written to the original
950 * file name and the file is a temporary, set the "no exit" bit. This
951 * permits the user to write the file and use it in the context of the
952 * filesystem, but still keeps them from discarding their changes by
955 if (LF_ISSET(FS_ALL) && !LF_ISSET(FS_APPEND)) {
956 F_CLR(ep, F_MODIFIED);
957 if (F_ISSET(frp, FR_TMPFILE))
959 F_SET(frp, FR_TMPEXIT);
961 F_CLR(frp, FR_TMPEXIT);
964 p = msg_print(sp, name, &nf);
968 "256|%s: new file: %lu lines, %lu characters", NULL);
969 len = snprintf(buf, sizeof(buf), msgstr, p, nlno, nch);
972 msgstr = msg_cat(sp, LF_ISSET(FS_APPEND) ?
973 "315|%s: appended: %lu lines, %lu characters" :
974 "257|%s: %lu lines, %lu characters", NULL);
975 len = snprintf(buf, sizeof(buf), msgstr, p, nlno, nch);
982 * There's a nasty problem with long path names. Cscope and tags files
983 * can result in long paths and vi will request a continuation key from
984 * the user. Unfortunately, the user has typed ahead, and chaos will
985 * result. If we assume that the characters in the filenames only take
986 * a single screen column each, we can trim the filename.
989 if (len >= sp->cols) {
990 for (s = buf, t = buf + strlen(p); s < t &&
991 (*s != '/' || len >= sp->cols - 3); ++s, --len);
995 *--s = '.'; /* Leading ellipses. */
1000 msgq(sp, M_INFO, "%s", s);
1002 FREE_SPACE(sp, p, 0);
1008 * Backup the about-to-be-written file.
1011 * We do the backup by copying the entire file. It would be nice to do
1012 * a rename instead, but: (1) both files may not fit and we want to fail
1013 * before doing the rename; (2) the backup file may not be on the same
1014 * disk partition as the file being written; (3) there may be optional
1015 * file information (MACs, DACs, whatever) that we won't get right if we
1016 * recreate the file. So, let's not risk it.
1030 int flags, maxnum, nr, num, nw, rfd, wfd, version;
1031 char *bp, *estr, *p, *pct, *slash, *t, *wfname, buf[8192];
1038 bp = estr = wfname = NULL;
1041 * Open the current file for reading. Do this first, so that
1042 * we don't exec a shell before the most likely failure point.
1043 * If it doesn't exist, it's okay, there's just nothing to back
1047 if ((rfd = open(name, O_RDONLY, 0)) < 0) {
1048 if (errno == ENOENT)
1055 * If the name starts with an 'N' character, add a version number
1056 * to the name. Strip the leading N from the string passed to the
1057 * expansion routines, for no particular reason. It would be nice
1058 * to permit users to put the version number anywhere in the backup
1059 * name, but there isn't a special character that we can use in the
1060 * name, and giving a new character a special meaning leads to ugly
1061 * hacks both here and in the supporting ex routines.
1063 * Shell and file name expand the option's value.
1065 ex_cinit(sp, &cmd, 0, 0, 0, 0, 0);
1066 if (bname[0] == 'N') {
1071 CHAR2INT(sp, bname, strlen(bname), wp, wlen);
1072 if ((wp = v_wstrdup(sp, wp, wlen)) == NULL)
1074 if (argv_exp2(sp, &cmd, wp, wlen)) {
1081 * 0 args: impossible.
1083 * >1 args: object, too many args.
1085 if (cmd.argc != 1) {
1086 msgq_str(sp, M_ERR, bname,
1087 "258|%s expanded into too many file names");
1093 * If appending a version number, read through the directory, looking
1094 * for file names that match the name followed by a number. Make all
1095 * of the other % characters in name literal, so the user doesn't get
1096 * surprised and sscanf doesn't drop core indirecting through pointers
1097 * that don't exist. If any such files are found, increment its number
1101 GET_SPACE_GOTOC(sp, bp, blen, cmd.argv[0]->len * 2 + 50);
1102 INT2CHAR(sp, cmd.argv[0]->bp, cmd.argv[0]->len + 1,
1106 for (t = bp, slash = NULL;
1107 p[0] != '\0'; *t++ = *p++)
1111 } else if (p[0] == '/')
1118 if (slash == NULL) {
1119 dirp = opendir(".");
1128 INT2CHAR(sp, cmd.argv[0]->bp, cmd.argv[0]->len + 1,
1133 for (maxnum = 0; (dp = readdir(dirp)) != NULL;)
1134 if (sscanf(dp->d_name, p, &num) == 1 && num > maxnum)
1136 (void)closedir(dirp);
1138 /* Format the backup file name. */
1139 (void)snprintf(pct, blen - (pct - bp), "%d", maxnum + 1);
1143 INT2CHAR(sp, cmd.argv[0]->bp, cmd.argv[0]->len + 1,
1147 /* Open the backup file, avoiding lurkers. */
1148 if (stat(wfname, &sb) == 0) {
1149 if (!S_ISREG(sb.st_mode)) {
1150 msgq_str(sp, M_ERR, bname,
1151 "259|%s: not a regular file");
1154 if (sb.st_uid != getuid()) {
1155 msgq_str(sp, M_ERR, bname, "260|%s: not owned by you");
1158 if (sb.st_mode & (S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)) {
1159 msgq_str(sp, M_ERR, bname,
1160 "261|%s: accessible by a user other than the owner");
1165 flags = O_CREAT | O_EXCL;
1166 if ((wfd = open(wfname, flags | O_WRONLY, S_IRUSR | S_IWUSR)) < 0) {
1171 /* Copy the file's current contents to its backup value. */
1172 while ((nr = read(rfd, buf, sizeof(buf))) > 0)
1173 for (off = 0; nr != 0; nr -= nw, off += nw)
1174 if ((nw = write(wfd, buf + off, nr)) < 0) {
1192 FREE_SPACE(sp, bp, blen);
1199 (void)unlink(wfname);
1203 msgq_str(sp, M_SYSERR, estr, "%s");
1207 FREE_SPACE(sp, bp, blen);
1213 * Read the first line and set the O_FILEENCODING.
1216 file_encinit(SCR *sp)
1218 #if defined(USE_WIDECHAR) && defined(USE_ICONV)
1222 char buf[4096]; /* not need to be '\0'-terminated */
1228 while (!db_rget(sp, ln++, &p, &len)) {
1229 if (blen + len > sizeof(buf))
1230 len = sizeof(buf) - blen;
1231 memcpy(buf + blen, p, len);
1233 if (blen == sizeof(buf))
1240 * Detect UTF-8 and fallback to the locale/preset encoding.
1243 * A manually set O_FILEENCODING indicates the "fallback
1244 * encoding", but UTF-8, which can be safely detected, is not
1245 * inherited from the old screen.
1247 if (looks_utf8(buf, blen) > 1)
1248 o_set(sp, O_FILEENCODING, OS_STRDUP, "utf-8", 0);
1249 else if (!O_ISSET(sp, O_FILEENCODING) ||
1250 !strcasecmp(O_STR(sp, O_FILEENCODING), "utf-8"))
1251 o_set(sp, O_FILEENCODING, OS_STRDUP, codeset(), 0);
1253 conv_enc(sp, O_FILEENCODING, 0);
1259 * Skip the first comment.
1262 file_comment(SCR *sp)
1268 for (lno = 1; !db_get(sp, lno, 0, &p, &len) && len == 0; ++lno);
1272 F_SET(sp, SC_SCR_TOP);
1273 while (!db_get(sp, ++lno, 0, &p, &len))
1274 if (len < 1 || p[0] != '#') {
1278 } else if (len > 1 && p[0] == '/' && p[1] == '*') {
1279 F_SET(sp, SC_SCR_TOP);
1281 for (; len > 1; --len, ++p)
1282 if (p[0] == '*' && p[1] == '/') {
1286 } while (!db_get(sp, ++lno, 0, &p, &len));
1287 } else if (len > 1 && p[0] == '/' && p[1] == '/') {
1288 F_SET(sp, SC_SCR_TOP);
1292 for (; len > 1; --len, ++p)
1293 if (p[0] == '/' && p[1] == '/') {
1297 } while (!db_get(sp, ++lno, 0, &p, &len));
1303 * First modification check routine. The :next, :prev, :rewind, :tag,
1304 * :tagpush, :tagpop, ^^ modifications check.
1306 * PUBLIC: int file_m1(SCR *, int, int);
1318 /* If no file loaded, return no modifications. */
1323 * If the file has been modified, we'll want to write it back or
1324 * fail. If autowrite is set, we'll write it back automatically,
1325 * unless force is also set. Otherwise, we fail unless forced or
1326 * there's another open screen on this file.
1328 if (F_ISSET(ep, F_MODIFIED))
1329 if (O_ISSET(sp, O_AUTOWRITE)) {
1330 if (!force && file_aw(sp, flags))
1332 } else if (ep->refcnt <= 1 && !force) {
1333 msgq(sp, M_ERR, LF_ISSET(FS_POSSIBLE) ?
1334 "262|File modified since last complete write; write or use ! to override" :
1335 "263|File modified since last complete write; write or use :edit! to override");
1339 return (file_m3(sp, force));
1344 * Second modification check routine. The :edit, :quit, :recover
1345 * modifications check.
1347 * PUBLIC: int file_m2(SCR *, int);
1358 /* If no file loaded, return no modifications. */
1363 * If the file has been modified, we'll want to fail, unless forced
1364 * or there's another open screen on this file.
1366 if (F_ISSET(ep, F_MODIFIED) && ep->refcnt <= 1 && !force) {
1368 "264|File modified since last complete write; write or use ! to override");
1372 return (file_m3(sp, force));
1377 * Third modification check routine.
1379 * PUBLIC: int file_m3(SCR *, int);
1390 /* If no file loaded, return no modifications. */
1395 * Don't exit while in a temporary files if the file was ever modified.
1396 * The problem is that if the user does a ":wq", we write and quit,
1397 * unlinking the temporary file. Not what the user had in mind at all.
1398 * We permit writing to temporary files, so that user maps using file
1399 * system names work with temporary files.
1401 if (F_ISSET(sp->frp, FR_TMPEXIT) && ep->refcnt <= 1 && !force) {
1403 "265|File is a temporary; exit will discard modifications");
1411 * Autowrite routine. If modified, autowrite is set and the readonly bit
1412 * is not set, write the file. A routine so there's a place to put the
1415 * PUBLIC: int file_aw(SCR *, int);
1422 if (!F_ISSET(sp->ep, F_MODIFIED))
1424 if (!O_ISSET(sp, O_AUTOWRITE))
1429 * Historic 4BSD vi attempted to write the file if autowrite was set,
1430 * regardless of the writeability of the file (as defined by the file
1431 * readonly flag). System V changed this as some point, not attempting
1432 * autowrite if the file was readonly. This feels like a bug fix to
1433 * me (e.g. the principle of least surprise is violated if readonly is
1434 * set and vi writes the file), so I'm compatible with System V.
1436 if (O_ISSET(sp, O_READONLY)) {
1438 "266|File readonly, modifications not auto-written");
1441 return (file_write(sp, NULL, NULL, NULL, flags));
1446 * Set the alternate pathname.
1448 * Set the alternate pathname. It's a routine because I wanted some place
1449 * to hang this comment. The alternate pathname (normally referenced using
1450 * the special character '#' during file expansion and in the vi ^^ command)
1451 * is set by almost all ex commands that take file names as arguments. The
1452 * rules go something like this:
1454 * 1: If any ex command takes a file name as an argument (except for the
1455 * :next command), the alternate pathname is set to that file name.
1456 * This excludes the command ":e" and ":w !command" as no file name
1457 * was specified. Note, historically, the :source command did not set
1458 * the alternate pathname. It does in nvi, for consistency.
1460 * 2: However, if any ex command sets the current pathname, e.g. the
1461 * ":e file" or ":rew" commands succeed, then the alternate pathname
1462 * is set to the previous file's current pathname, if it had one.
1463 * This includes the ":file" command and excludes the ":e" command.
1464 * So, by rule #1 and rule #2, if ":edit foo" fails, the alternate
1465 * pathname will be "foo", if it succeeds, the alternate pathname will
1466 * be the previous current pathname. The ":e" command will not set
1467 * the alternate or current pathnames regardless.
1469 * 3: However, if it's a read or write command with a file argument and
1470 * the current pathname has not yet been set, the file name becomes
1471 * the current pathname, and the alternate pathname is unchanged.
1473 * If the user edits a temporary file, there may be times when there is no
1474 * alternative file name. A name argument of NULL turns it off.
1476 * PUBLIC: void set_alt_name(SCR *, char *);
1483 if (sp->alt_name != NULL)
1486 sp->alt_name = NULL;
1487 else if ((sp->alt_name = strdup(name)) == NULL)
1488 msgq(sp, M_SYSERR, NULL);
1493 * Get an exclusive lock on a file.
1495 * PUBLIC: lockr_t file_lock(SCR *, char *, int, int);
1504 if (!O_ISSET(sp, O_LOCKFILES))
1505 return (LOCK_SUCCESS);
1509 * We need to distinguish a lock not being available for the file
1510 * from the file system not supporting locking. Flock is documented
1511 * as returning EWOULDBLOCK; add EAGAIN for good measure, and assume
1512 * they are the former. There's no portable way to do this.
1515 if (!flock(fd, LOCK_EX | LOCK_NB)) {
1516 fcntl(fd, F_SETFD, 1);
1517 return (LOCK_SUCCESS);
1519 return (errno == EAGAIN
1521 || errno == EWOULDBLOCK
1523 ? LOCK_UNAVAIL : LOCK_FAILED);