1 /*
2 * Copyright (C) 1984-2021 Mark Nudelman
3 *
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
6 *
7 * For more information, see the README file.
8 */
9
10
11 /*
12 * Routines to mess around with filenames (and files).
13 * Much of this is very OS dependent.
14 */
15
16 #include "less.h"
17 #include "lglob.h"
18 #if MSDOS_COMPILER
19 #include <dos.h>
20 #if MSDOS_COMPILER==WIN32C && !defined(_MSC_VER)
21 #include <dir.h>
22 #endif
23 #if MSDOS_COMPILER==DJGPPC
24 #include <glob.h>
25 #include <dir.h>
26 #define _MAX_PATH PATH_MAX
27 #endif
28 #endif
29 #ifdef _OSK
30 #include <rbf.h>
31 #ifndef _OSK_MWC32
32 #include <modes.h>
33 #endif
34 #endif
35
36 #if HAVE_STAT
37 #include <sys/stat.h>
38 #ifndef S_ISDIR
39 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
40 #endif
41 #ifndef S_ISREG
42 #define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
43 #endif
44 #endif
45
46 extern int force_open;
47 extern int secure;
48 extern int use_lessopen;
49 extern int ctldisp;
50 extern int utf_mode;
51 extern IFILE curr_ifile;
52 extern IFILE old_ifile;
53 #if SPACES_IN_FILENAMES
54 extern char openquote;
55 extern char closequote;
56 #endif
57
58 /*
59 * Remove quotes around a filename.
60 */
61 public char *
shell_unquote(str)62 shell_unquote(str)
63 char *str;
64 {
65 char *name;
66 char *p;
67
68 name = p = (char *) ecalloc(strlen(str)+1, sizeof(char));
69 if (*str == openquote)
70 {
71 str++;
72 while (*str != '\0')
73 {
74 if (*str == closequote)
75 {
76 if (str[1] != closequote)
77 break;
78 str++;
79 }
80 *p++ = *str++;
81 }
82 } else
83 {
84 char *esc = get_meta_escape();
85 int esclen = (int) strlen(esc);
86 while (*str != '\0')
87 {
88 if (esclen > 0 && strncmp(str, esc, esclen) == 0)
89 str += esclen;
90 *p++ = *str++;
91 }
92 }
93 *p = '\0';
94 return (name);
95 }
96
97 /*
98 * Get the shell's escape character.
99 */
100 public char *
get_meta_escape(VOID_PARAM)101 get_meta_escape(VOID_PARAM)
102 {
103 char *s;
104
105 s = lgetenv("LESSMETAESCAPE");
106 if (s == NULL)
107 s = DEF_METAESCAPE;
108 return (s);
109 }
110
111 /*
112 * Get the characters which the shell considers to be "metacharacters".
113 */
114 static char *
metachars(VOID_PARAM)115 metachars(VOID_PARAM)
116 {
117 static char *mchars = NULL;
118
119 if (mchars == NULL)
120 {
121 mchars = lgetenv("LESSMETACHARS");
122 if (mchars == NULL)
123 mchars = DEF_METACHARS;
124 }
125 return (mchars);
126 }
127
128 /*
129 * Is this a shell metacharacter?
130 */
131 static int
metachar(c)132 metachar(c)
133 char c;
134 {
135 return (strchr(metachars(), c) != NULL);
136 }
137
138 /*
139 * Insert a backslash before each metacharacter in a string.
140 */
141 public char *
shell_quote(s)142 shell_quote(s)
143 char *s;
144 {
145 char *p;
146 char *newstr;
147 int len;
148 char *esc = get_meta_escape();
149 int esclen = (int) strlen(esc);
150 int use_quotes = 0;
151 int have_quotes = 0;
152
153 /*
154 * Determine how big a string we need to allocate.
155 */
156 len = 1; /* Trailing null byte */
157 for (p = s; *p != '\0'; p++)
158 {
159 len++;
160 if (*p == openquote || *p == closequote)
161 have_quotes = 1;
162 if (metachar(*p))
163 {
164 if (esclen == 0)
165 {
166 /*
167 * We've got a metachar, but this shell
168 * doesn't support escape chars. Use quotes.
169 */
170 use_quotes = 1;
171 } else
172 {
173 /*
174 * Allow space for the escape char.
175 */
176 len += esclen;
177 }
178 }
179 }
180 if (use_quotes)
181 {
182 if (have_quotes)
183 /*
184 * We can't quote a string that contains quotes.
185 */
186 return (NULL);
187 len = (int) strlen(s) + 3;
188 }
189 /*
190 * Allocate and construct the new string.
191 */
192 newstr = p = (char *) ecalloc(len, sizeof(char));
193 if (use_quotes)
194 {
195 SNPRINTF3(newstr, len, "%c%s%c", openquote, s, closequote);
196 } else
197 {
198 while (*s != '\0')
199 {
200 if (metachar(*s))
201 {
202 /*
203 * Add the escape char.
204 */
205 strcpy(p, esc);
206 p += esclen;
207 }
208 *p++ = *s++;
209 }
210 *p = '\0';
211 }
212 return (newstr);
213 }
214
215 /*
216 * Return a pathname that points to a specified file in a specified directory.
217 * Return NULL if the file does not exist in the directory.
218 */
219 static char *
dirfile(dirname,filename)220 dirfile(dirname, filename)
221 char *dirname;
222 char *filename;
223 {
224 char *pathname;
225 int len;
226 int f;
227
228 if (dirname == NULL || *dirname == '\0')
229 return (NULL);
230 /*
231 * Construct the full pathname.
232 */
233 len = (int) (strlen(dirname) + strlen(filename) + 2);
234 pathname = (char *) calloc(len, sizeof(char));
235 if (pathname == NULL)
236 return (NULL);
237 SNPRINTF3(pathname, len, "%s%s%s", dirname, PATHNAME_SEP, filename);
238 /*
239 * Make sure the file exists.
240 */
241 f = open(pathname, OPEN_READ);
242 if (f < 0)
243 {
244 free(pathname);
245 pathname = NULL;
246 } else
247 {
248 close(f);
249 }
250 return (pathname);
251 }
252
253 /*
254 * Return the full pathname of the given file in the "home directory".
255 */
256 public char *
homefile(filename)257 homefile(filename)
258 char *filename;
259 {
260 char *pathname;
261
262 /*
263 * Try $HOME/filename.
264 */
265 pathname = dirfile(lgetenv("HOME"), filename);
266 if (pathname != NULL)
267 return (pathname);
268 #if OS2
269 /*
270 * Try $INIT/filename.
271 */
272 pathname = dirfile(lgetenv("INIT"), filename);
273 if (pathname != NULL)
274 return (pathname);
275 #endif
276 #if MSDOS_COMPILER || OS2
277 /*
278 * Look for the file anywhere on search path.
279 */
280 pathname = (char *) calloc(_MAX_PATH, sizeof(char));
281 #if MSDOS_COMPILER==DJGPPC
282 {
283 char *res = searchpath(filename);
284 if (res == 0)
285 *pathname = '\0';
286 else
287 strcpy(pathname, res);
288 }
289 #else
290 _searchenv(filename, "PATH", pathname);
291 #endif
292 if (*pathname != '\0')
293 return (pathname);
294 free(pathname);
295 #endif
296 return (NULL);
297 }
298
299 /*
300 * Expand a string, substituting any "%" with the current filename,
301 * and any "#" with the previous filename.
302 * But a string of N "%"s is just replaced with N-1 "%"s.
303 * Likewise for a string of N "#"s.
304 * {{ This is a lot of work just to support % and #. }}
305 */
306 public char *
fexpand(s)307 fexpand(s)
308 char *s;
309 {
310 char *fr, *to;
311 int n;
312 char *e;
313 IFILE ifile;
314
315 #define fchar_ifile(c) \
316 ((c) == '%' ? curr_ifile : \
317 (c) == '#' ? old_ifile : NULL_IFILE)
318
319 /*
320 * Make one pass to see how big a buffer we
321 * need to allocate for the expanded string.
322 */
323 n = 0;
324 for (fr = s; *fr != '\0'; fr++)
325 {
326 switch (*fr)
327 {
328 case '%':
329 case '#':
330 if (fr > s && fr[-1] == *fr)
331 {
332 /*
333 * Second (or later) char in a string
334 * of identical chars. Treat as normal.
335 */
336 n++;
337 } else if (fr[1] != *fr)
338 {
339 /*
340 * Single char (not repeated). Treat specially.
341 */
342 ifile = fchar_ifile(*fr);
343 if (ifile == NULL_IFILE)
344 n++;
345 else
346 n += (int) strlen(get_filename(ifile));
347 }
348 /*
349 * Else it is the first char in a string of
350 * identical chars. Just discard it.
351 */
352 break;
353 default:
354 n++;
355 break;
356 }
357 }
358
359 e = (char *) ecalloc(n+1, sizeof(char));
360
361 /*
362 * Now copy the string, expanding any "%" or "#".
363 */
364 to = e;
365 for (fr = s; *fr != '\0'; fr++)
366 {
367 switch (*fr)
368 {
369 case '%':
370 case '#':
371 if (fr > s && fr[-1] == *fr)
372 {
373 *to++ = *fr;
374 } else if (fr[1] != *fr)
375 {
376 ifile = fchar_ifile(*fr);
377 if (ifile == NULL_IFILE)
378 *to++ = *fr;
379 else
380 {
381 strcpy(to, get_filename(ifile));
382 to += strlen(to);
383 }
384 }
385 break;
386 default:
387 *to++ = *fr;
388 break;
389 }
390 }
391 *to = '\0';
392 return (e);
393 }
394
395
396 #if TAB_COMPLETE_FILENAME
397
398 /*
399 * Return a blank-separated list of filenames which "complete"
400 * the given string.
401 */
402 public char *
fcomplete(s)403 fcomplete(s)
404 char *s;
405 {
406 char *fpat;
407 char *qs;
408
409 if (secure)
410 return (NULL);
411 /*
412 * Complete the filename "s" by globbing "s*".
413 */
414 #if MSDOS_COMPILER && (MSDOS_COMPILER == MSOFTC || MSDOS_COMPILER == BORLANDC)
415 /*
416 * But in DOS, we have to glob "s*.*".
417 * But if the final component of the filename already has
418 * a dot in it, just do "s*".
419 * (Thus, "FILE" is globbed as "FILE*.*",
420 * but "FILE.A" is globbed as "FILE.A*").
421 */
422 {
423 char *slash;
424 int len;
425 for (slash = s+strlen(s)-1; slash > s; slash--)
426 if (*slash == *PATHNAME_SEP || *slash == '/')
427 break;
428 len = (int) strlen(s) + 4;
429 fpat = (char *) ecalloc(len, sizeof(char));
430 if (strchr(slash, '.') == NULL)
431 SNPRINTF1(fpat, len, "%s*.*", s);
432 else
433 SNPRINTF1(fpat, len, "%s*", s);
434 }
435 #else
436 {
437 int len = (int) strlen(s) + 2;
438 fpat = (char *) ecalloc(len, sizeof(char));
439 SNPRINTF1(fpat, len, "%s*", s);
440 }
441 #endif
442 qs = lglob(fpat);
443 s = shell_unquote(qs);
444 if (strcmp(s,fpat) == 0)
445 {
446 /*
447 * The filename didn't expand.
448 */
449 free(qs);
450 qs = NULL;
451 }
452 free(s);
453 free(fpat);
454 return (qs);
455 }
456 #endif
457
458 /*
459 * Try to determine if a file is "binary".
460 * This is just a guess, and we need not try too hard to make it accurate.
461 */
462 public int
bin_file(f)463 bin_file(f)
464 int f;
465 {
466 int n;
467 int bin_count = 0;
468 char data[256];
469 char* p;
470 char* edata;
471
472 if (!seekable(f))
473 return (0);
474 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
475 return (0);
476 n = read(f, data, sizeof(data));
477 if (n <= 0)
478 return (0);
479 edata = &data[n];
480 for (p = data; p < edata; )
481 {
482 if (utf_mode && !is_utf8_well_formed(p, edata-data))
483 {
484 bin_count++;
485 utf_skip_to_lead(&p, edata);
486 } else
487 {
488 LWCHAR c = step_char(&p, +1, edata);
489 struct ansi_state *pansi;
490 if (ctldisp == OPT_ONPLUS && (pansi = ansi_start(c)) != NULL)
491 {
492 skip_ansi(pansi, &p, edata);
493 ansi_done(pansi);
494 } else if (binary_char(c))
495 bin_count++;
496 }
497 }
498 /*
499 * Call it a binary file if there are more than 5 binary characters
500 * in the first 256 bytes of the file.
501 */
502 return (bin_count > 5);
503 }
504
505 /*
506 * Try to determine the size of a file by seeking to the end.
507 */
508 static POSITION
seek_filesize(f)509 seek_filesize(f)
510 int f;
511 {
512 off_t spos;
513
514 spos = lseek(f, (off_t)0, SEEK_END);
515 if (spos == BAD_LSEEK)
516 return (NULL_POSITION);
517 return ((POSITION) spos);
518 }
519
520 /*
521 * Read a string from a file.
522 * Return a pointer to the string in memory.
523 */
524 static char *
readfd(fd)525 readfd(fd)
526 FILE *fd;
527 {
528 int len;
529 int ch;
530 char *buf;
531 char *p;
532
533 /*
534 * Make a guess about how many chars in the string
535 * and allocate a buffer to hold it.
536 */
537 len = 100;
538 buf = (char *) ecalloc(len, sizeof(char));
539 for (p = buf; ; p++)
540 {
541 if ((ch = getc(fd)) == '\n' || ch == EOF)
542 break;
543 if (p - buf >= len-1)
544 {
545 /*
546 * The string is too big to fit in the buffer we have.
547 * Allocate a new buffer, twice as big.
548 */
549 len *= 2;
550 *p = '\0';
551 p = (char *) ecalloc(len, sizeof(char));
552 strcpy(p, buf);
553 free(buf);
554 buf = p;
555 p = buf + strlen(buf);
556 }
557 *p = ch;
558 }
559 *p = '\0';
560 return (buf);
561 }
562
563
564
565 #if HAVE_POPEN
566
567 /*
568 * Execute a shell command.
569 * Return a pointer to a pipe connected to the shell command's standard output.
570 */
571 static FILE *
shellcmd(cmd)572 shellcmd(cmd)
573 char *cmd;
574 {
575 FILE *fd;
576
577 #if HAVE_SHELL
578 char *shell;
579
580 shell = lgetenv("SHELL");
581 if (!isnullenv(shell))
582 {
583 char *scmd;
584 char *esccmd;
585
586 /*
587 * Read the output of <$SHELL -c cmd>.
588 * Escape any metacharacters in the command.
589 */
590 esccmd = shell_quote(cmd);
591 if (esccmd == NULL)
592 {
593 fd = popen(cmd, "r");
594 } else
595 {
596 int len = (int) (strlen(shell) + strlen(esccmd) + 5);
597 scmd = (char *) ecalloc(len, sizeof(char));
598 SNPRINTF3(scmd, len, "%s %s %s", shell, shell_coption(), esccmd);
599 free(esccmd);
600 fd = popen(scmd, "r");
601 free(scmd);
602 }
603 } else
604 #endif
605 {
606 fd = popen(cmd, "r");
607 }
608 /*
609 * Redirection in `popen' might have messed with the
610 * standard devices. Restore binary input mode.
611 */
612 SET_BINARY(0);
613 return (fd);
614 }
615
616 #endif /* HAVE_POPEN */
617
618
619 /*
620 * Expand a filename, doing any system-specific metacharacter substitutions.
621 */
622 public char *
lglob(filename)623 lglob(filename)
624 char *filename;
625 {
626 char *gfilename;
627
628 filename = fexpand(filename);
629 if (secure)
630 return (filename);
631
632 #ifdef DECL_GLOB_LIST
633 {
634 /*
635 * The globbing function returns a list of names.
636 */
637 int length;
638 char *p;
639 char *qfilename;
640 DECL_GLOB_LIST(list)
641
642 GLOB_LIST(filename, list);
643 if (GLOB_LIST_FAILED(list))
644 {
645 return (filename);
646 }
647 length = 1; /* Room for trailing null byte */
648 for (SCAN_GLOB_LIST(list, p))
649 {
650 INIT_GLOB_LIST(list, p);
651 qfilename = shell_quote(p);
652 if (qfilename != NULL)
653 {
654 length += strlen(qfilename) + 1;
655 free(qfilename);
656 }
657 }
658 gfilename = (char *) ecalloc(length, sizeof(char));
659 for (SCAN_GLOB_LIST(list, p))
660 {
661 INIT_GLOB_LIST(list, p);
662 qfilename = shell_quote(p);
663 if (qfilename != NULL)
664 {
665 sprintf(gfilename + strlen(gfilename), "%s ", qfilename);
666 free(qfilename);
667 }
668 }
669 /*
670 * Overwrite the final trailing space with a null terminator.
671 */
672 *--p = '\0';
673 GLOB_LIST_DONE(list);
674 }
675 #else
676 #ifdef DECL_GLOB_NAME
677 {
678 /*
679 * The globbing function returns a single name, and
680 * is called multiple times to walk thru all names.
681 */
682 char *p;
683 int len;
684 int n;
685 char *pfilename;
686 char *qfilename;
687 DECL_GLOB_NAME(fnd,drive,dir,fname,ext,handle)
688
689 GLOB_FIRST_NAME(filename, &fnd, handle);
690 if (GLOB_FIRST_FAILED(handle))
691 {
692 return (filename);
693 }
694
695 _splitpath(filename, drive, dir, fname, ext);
696 len = 100;
697 gfilename = (char *) ecalloc(len, sizeof(char));
698 p = gfilename;
699 do {
700 n = (int) (strlen(drive) + strlen(dir) + strlen(fnd.GLOB_NAME) + 1);
701 pfilename = (char *) ecalloc(n, sizeof(char));
702 SNPRINTF3(pfilename, n, "%s%s%s", drive, dir, fnd.GLOB_NAME);
703 qfilename = shell_quote(pfilename);
704 free(pfilename);
705 if (qfilename != NULL)
706 {
707 n = (int) strlen(qfilename);
708 while (p - gfilename + n + 2 >= len)
709 {
710 /*
711 * No room in current buffer.
712 * Allocate a bigger one.
713 */
714 len *= 2;
715 *p = '\0';
716 p = (char *) ecalloc(len, sizeof(char));
717 strcpy(p, gfilename);
718 free(gfilename);
719 gfilename = p;
720 p = gfilename + strlen(gfilename);
721 }
722 strcpy(p, qfilename);
723 free(qfilename);
724 p += n;
725 *p++ = ' ';
726 }
727 } while (GLOB_NEXT_NAME(handle, &fnd) == 0);
728
729 /*
730 * Overwrite the final trailing space with a null terminator.
731 */
732 *--p = '\0';
733 GLOB_NAME_DONE(handle);
734 }
735 #else
736 #if HAVE_POPEN
737 {
738 /*
739 * We get the shell to glob the filename for us by passing
740 * an "echo" command to the shell and reading its output.
741 */
742 FILE *fd;
743 char *s;
744 char *lessecho;
745 char *cmd;
746 char *esc;
747 int len;
748
749 esc = get_meta_escape();
750 if (strlen(esc) == 0)
751 esc = "-";
752 esc = shell_quote(esc);
753 if (esc == NULL)
754 {
755 return (filename);
756 }
757 lessecho = lgetenv("LESSECHO");
758 if (isnullenv(lessecho))
759 lessecho = "lessecho";
760 /*
761 * Invoke lessecho, and read its output (a globbed list of filenames).
762 */
763 len = (int) (strlen(lessecho) + strlen(filename) + (7*strlen(metachars())) + 24);
764 cmd = (char *) ecalloc(len, sizeof(char));
765 SNPRINTF4(cmd, len, "%s -p0x%x -d0x%x -e%s ", lessecho, openquote, closequote, esc);
766 free(esc);
767 for (s = metachars(); *s != '\0'; s++)
768 sprintf(cmd + strlen(cmd), "-n0x%x ", *s);
769 sprintf(cmd + strlen(cmd), "-- %s", filename);
770 fd = shellcmd(cmd);
771 free(cmd);
772 if (fd == NULL)
773 {
774 /*
775 * Cannot create the pipe.
776 * Just return the original (fexpanded) filename.
777 */
778 return (filename);
779 }
780 gfilename = readfd(fd);
781 pclose(fd);
782 if (*gfilename == '\0')
783 {
784 free(gfilename);
785 return (filename);
786 }
787 }
788 #else
789 /*
790 * No globbing functions at all. Just use the fexpanded filename.
791 */
792 gfilename = save(filename);
793 #endif
794 #endif
795 #endif
796 free(filename);
797 return (gfilename);
798 }
799
800 /*
801 * Return canonical pathname.
802 */
803 public char *
lrealpath(path)804 lrealpath(path)
805 char *path;
806 {
807 #if HAVE_REALPATH
808 char rpath[PATH_MAX];
809 if (realpath(path, rpath) != NULL)
810 return (save(rpath));
811 #endif
812 return (save(path));
813 }
814
815 /*
816 * Return number of %s escapes in a string.
817 * Return a large number if there are any other % escapes besides %s.
818 */
819 static int
num_pct_s(lessopen)820 num_pct_s(lessopen)
821 char *lessopen;
822 {
823 int num = 0;
824
825 while (*lessopen != '\0')
826 {
827 if (*lessopen == '%')
828 {
829 if (lessopen[1] == '%')
830 ++lessopen;
831 else if (lessopen[1] == 's')
832 ++num;
833 else
834 return (999);
835 }
836 ++lessopen;
837 }
838 return (num);
839 }
840
841 /*
842 * See if we should open a "replacement file"
843 * instead of the file we're about to open.
844 */
845 public char *
open_altfile(filename,pf,pfd)846 open_altfile(filename, pf, pfd)
847 char *filename;
848 int *pf;
849 void **pfd;
850 {
851 #if !HAVE_POPEN
852 return (NULL);
853 #else
854 char *lessopen;
855 char *qfilename;
856 char *cmd;
857 int len;
858 FILE *fd;
859 #if HAVE_FILENO
860 int returnfd = 0;
861 #endif
862
863 if (!use_lessopen || secure)
864 return (NULL);
865 ch_ungetchar(-1);
866 if ((lessopen = lgetenv("LESSOPEN")) == NULL)
867 return (NULL);
868 while (*lessopen == '|')
869 {
870 /*
871 * If LESSOPEN starts with a |, it indicates
872 * a "pipe preprocessor".
873 */
874 #if !HAVE_FILENO
875 error("LESSOPEN pipe is not supported", NULL_PARG);
876 return (NULL);
877 #else
878 lessopen++;
879 returnfd++;
880 #endif
881 }
882 if (*lessopen == '-')
883 {
884 /*
885 * Lessopen preprocessor will accept "-" as a filename.
886 */
887 lessopen++;
888 } else
889 {
890 if (strcmp(filename, "-") == 0)
891 return (NULL);
892 }
893 if (num_pct_s(lessopen) != 1)
894 {
895 error("LESSOPEN ignored: must contain exactly one %%s", NULL_PARG);
896 return (NULL);
897 }
898
899 qfilename = shell_quote(filename);
900 len = (int) (strlen(lessopen) + strlen(qfilename) + 2);
901 cmd = (char *) ecalloc(len, sizeof(char));
902 SNPRINTF1(cmd, len, lessopen, qfilename);
903 free(qfilename);
904 fd = shellcmd(cmd);
905 free(cmd);
906 if (fd == NULL)
907 {
908 /*
909 * Cannot create the pipe.
910 */
911 return (NULL);
912 }
913 #if HAVE_FILENO
914 if (returnfd)
915 {
916 char c;
917 int f;
918
919 /*
920 * The alt file is a pipe. Read one char
921 * to see if the pipe will produce any data.
922 * If it does, push the char back on the pipe.
923 */
924 f = fileno(fd);
925 SET_BINARY(f);
926 if (read(f, &c, 1) != 1)
927 {
928 /*
929 * Pipe is empty.
930 * If more than 1 pipe char was specified,
931 * the exit status tells whether the file itself
932 * is empty, or if there is no alt file.
933 * If only one pipe char, just assume no alt file.
934 */
935 int status = pclose(fd);
936 if (returnfd > 1 && status == 0) {
937 /* File is empty. */
938 *pfd = NULL;
939 *pf = -1;
940 return (save(FAKE_EMPTYFILE));
941 }
942 /* No alt file. */
943 return (NULL);
944 }
945 /* Alt pipe contains data, so use it. */
946 ch_ungetchar(c);
947 *pfd = (void *) fd;
948 *pf = f;
949 return (save("-"));
950 }
951 #endif
952 /* The alt file is a regular file. Read its name from LESSOPEN. */
953 cmd = readfd(fd);
954 pclose(fd);
955 if (*cmd == '\0')
956 /*
957 * Pipe is empty. This means there is no alt file.
958 */
959 return (NULL);
960 return (cmd);
961 #endif /* HAVE_POPEN */
962 }
963
964 /*
965 * Close a replacement file.
966 */
967 public void
close_altfile(altfilename,filename)968 close_altfile(altfilename, filename)
969 char *altfilename;
970 char *filename;
971 {
972 #if HAVE_POPEN
973 char *lessclose;
974 FILE *fd;
975 char *cmd;
976 int len;
977
978 if (secure)
979 return;
980 ch_ungetchar(-1);
981 if ((lessclose = lgetenv("LESSCLOSE")) == NULL)
982 return;
983 if (num_pct_s(lessclose) > 2)
984 {
985 error("LESSCLOSE ignored; must contain no more than 2 %%s", NULL_PARG);
986 return;
987 }
988 len = (int) (strlen(lessclose) + strlen(filename) + strlen(altfilename) + 2);
989 cmd = (char *) ecalloc(len, sizeof(char));
990 SNPRINTF2(cmd, len, lessclose, filename, altfilename);
991 fd = shellcmd(cmd);
992 free(cmd);
993 if (fd != NULL)
994 pclose(fd);
995 #endif
996 }
997
998 /*
999 * Is the specified file a directory?
1000 */
1001 public int
is_dir(filename)1002 is_dir(filename)
1003 char *filename;
1004 {
1005 int isdir = 0;
1006
1007 #if HAVE_STAT
1008 {
1009 int r;
1010 struct stat statbuf;
1011
1012 r = stat(filename, &statbuf);
1013 isdir = (r >= 0 && S_ISDIR(statbuf.st_mode));
1014 }
1015 #else
1016 #ifdef _OSK
1017 {
1018 int f;
1019
1020 f = open(filename, S_IREAD | S_IFDIR);
1021 if (f >= 0)
1022 close(f);
1023 isdir = (f >= 0);
1024 }
1025 #endif
1026 #endif
1027 return (isdir);
1028 }
1029
1030 /*
1031 * Returns NULL if the file can be opened and
1032 * is an ordinary file, otherwise an error message
1033 * (if it cannot be opened or is a directory, etc.)
1034 */
1035 public char *
bad_file(filename)1036 bad_file(filename)
1037 char *filename;
1038 {
1039 char *m = NULL;
1040
1041 if (!force_open && is_dir(filename))
1042 {
1043 static char is_a_dir[] = " is a directory";
1044
1045 m = (char *) ecalloc(strlen(filename) + sizeof(is_a_dir),
1046 sizeof(char));
1047 strcpy(m, filename);
1048 strcat(m, is_a_dir);
1049 } else
1050 {
1051 #if HAVE_STAT
1052 int r;
1053 struct stat statbuf;
1054
1055 r = stat(filename, &statbuf);
1056 if (r < 0)
1057 {
1058 m = errno_message(filename);
1059 } else if (force_open)
1060 {
1061 m = NULL;
1062 } else if (!S_ISREG(statbuf.st_mode))
1063 {
1064 static char not_reg[] = " is not a regular file (use -f to see it)";
1065 m = (char *) ecalloc(strlen(filename) + sizeof(not_reg),
1066 sizeof(char));
1067 strcpy(m, filename);
1068 strcat(m, not_reg);
1069 }
1070 #endif
1071 }
1072 return (m);
1073 }
1074
1075 /*
1076 * Return the size of a file, as cheaply as possible.
1077 * In Unix, we can stat the file.
1078 */
1079 public POSITION
filesize(f)1080 filesize(f)
1081 int f;
1082 {
1083 #if HAVE_STAT
1084 struct stat statbuf;
1085
1086 if (fstat(f, &statbuf) >= 0)
1087 return ((POSITION) statbuf.st_size);
1088 #else
1089 #ifdef _OSK
1090 long size;
1091
1092 if ((size = (long) _gs_size(f)) >= 0)
1093 return ((POSITION) size);
1094 #endif
1095 #endif
1096 return (seek_filesize(f));
1097 }
1098
1099 /*
1100 *
1101 */
1102 public char *
shell_coption(VOID_PARAM)1103 shell_coption(VOID_PARAM)
1104 {
1105 return ("-c");
1106 }
1107
1108 /*
1109 * Return last component of a pathname.
1110 */
1111 public char *
last_component(name)1112 last_component(name)
1113 char *name;
1114 {
1115 char *slash;
1116
1117 for (slash = name + strlen(name); slash > name; )
1118 {
1119 --slash;
1120 if (*slash == *PATHNAME_SEP || *slash == '/')
1121 return (slash + 1);
1122 }
1123 return (name);
1124 }
1125
1126