Linux preempt-rt

Check our new training course

Real-Time Linux with PREEMPT_RT

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
/*
 * Utility routines.
 *
 * Copyright (C) tons of folks.  Tracking down who wrote what
 * isn't something I'm going to worry about...  If you wrote something
 * here, please feel free to acknowledge your work.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
 * Permission has been granted to redistribute this code under the GPL.
 *
 */

#include "internal.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <dirent.h>
#include <time.h>
#include <utime.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>

#ifdef BB_MTAB
const char mtab_file[] = "/etc/mtab";
#else
#if defined BB_MOUNT || defined BB_UMOUNT || defined BB_DF
const char mtab_file[] = "/proc/mounts";
#endif
#endif


/* volatile so gcc knows this is the enod of the line */
volatile void usage(const char *usage)
{
    fprintf(stderr, "BusyBox v%s (%s) multi-call binary -- GPL2\n\n", BB_VER, BB_BT);
    fprintf(stderr, "Usage: %s\n", usage);
    exit(FALSE);
}


#if defined (BB_INIT) || defined (BB_PS)

/* Returns kernel version encoded as major*65536 + minor*256 + patch,
 * so, for example,  to check if the kernel is greater than 2.2.11:
 *	if (get_kernel_revision() <= 2*65536+2*256+11) { <stuff> }
 */
int
get_kernel_revision()
{
  FILE *file;
  int major=0, minor=0, patch=0;
  char* filename="/proc/sys/kernel/osrelease";

  file = fopen(filename,"r");
  if (file == NULL) {
    /* bummer, /proc must not be mounted... */
    return( 0);
  }
  fscanf(file,"%d.%d.%d",&major,&minor,&patch);
  fclose(file);
  return major*65536 + minor*256 + patch;
}

#endif



#if defined (BB_CP) || defined (BB_MV)
/*
 * Return TRUE if a fileName is a directory.
 * Nonexistant files return FALSE.
 */
int isDirectory(const char *name)
{
    struct stat statBuf;

    if (stat(name, &statBuf) < 0)
	return FALSE;
    if (S_ISDIR(statBuf.st_mode))
	return TRUE;
    return(FALSE);
}


/*
 * Copy one file to another, while possibly preserving its modes, times,
 * and modes.  Returns TRUE if successful, or FALSE on a failure with an
 * error message output.  (Failure is not indicted if the attributes cannot
 * be set.)
 *  -Erik Andersen
 */
int
copyFile( const char *srcName, const char *destName, 
	 int setModes, int followLinks)
{
    int rfd;
    int wfd;
    int rcc;
    int result;
    char buf[BUF_SIZE];
    struct stat srcStatBuf;
    struct stat dstStatBuf;
    struct utimbuf times;

    if (followLinks == FALSE)
	result = stat(srcName, &srcStatBuf);
    else 
	result = lstat(srcName, &srcStatBuf);
    if (result < 0) {
	perror(srcName);
	return FALSE;
    }

    if (followLinks == FALSE)
	result = stat(destName, &dstStatBuf);
    else 
	result = lstat(destName, &dstStatBuf);
    if (result < 0) {
	dstStatBuf.st_ino = -1;
	dstStatBuf.st_dev = -1;
    }

    if ((srcStatBuf.st_dev == dstStatBuf.st_dev) &&
	(srcStatBuf.st_ino == dstStatBuf.st_ino)) {
	fprintf(stderr, "Copying file \"%s\" to itself\n", srcName);
	return FALSE;
    }

    if (S_ISDIR(srcStatBuf.st_mode)) {
	//fprintf(stderr, "copying directory %s to %s\n", srcName, destName);
	/* Make sure the directory is writable */
	if (mkdir(destName, 0777777 ^ umask(0))) {
	    perror(destName);
	    return (FALSE);
	}
    } else if (S_ISLNK(srcStatBuf.st_mode)) {
	char *link_val;
	int link_size;

	//fprintf(stderr, "copying link %s to %s\n", srcName, destName);
	link_val = (char *) alloca(PATH_MAX + 2);
	link_size = readlink(srcName, link_val, PATH_MAX + 1);
	if (link_size < 0) {
	    perror(srcName);
	    return (FALSE);
	}
	link_val[link_size] = '\0';
	link_size = symlink(link_val, destName);
	if (link_size != 0) {
	    perror(destName);
	    return (FALSE);
	}
    } else if (S_ISFIFO(srcStatBuf.st_mode)) {
	//fprintf(stderr, "copying fifo %s to %s\n", srcName, destName);
	if (mkfifo(destName, 644)) {
	    perror(destName);
	    return (FALSE);
	}
    } else if (S_ISBLK(srcStatBuf.st_mode) || S_ISCHR(srcStatBuf.st_mode) 
	    || S_ISSOCK (srcStatBuf.st_mode)) {
	//fprintf(stderr, "copying soc, blk, or chr %s to %s\n", srcName, destName);
	if (mknod(destName, srcStatBuf.st_mode, srcStatBuf.st_rdev)) {
	    perror(destName);
	    return (FALSE);
	}
    } else if (S_ISREG(srcStatBuf.st_mode)) {
	//fprintf(stderr, "copying regular file %s to %s\n", srcName, destName);
	rfd = open(srcName, O_RDONLY);
	if (rfd < 0) {
	    perror(srcName);
	    return FALSE;
	}

	wfd = creat(destName, srcStatBuf.st_mode);
	if (wfd < 0) {
	    perror(destName);
	    close(rfd);
	    return FALSE;
	}

	while ((rcc = read(rfd, buf, sizeof(buf))) > 0) {
	    if (fullWrite(wfd, buf, rcc) < 0)
		goto error_exit;
	}
	if (rcc < 0) {
	    goto error_exit;
	}

	close(rfd);
	if (close(wfd) < 0) {
	    return FALSE;
	}
    }

    if (setModes == TRUE) {
	//fprintf(stderr, "Setting permissions for %s\n", destName);
	chmod(destName, srcStatBuf.st_mode);
	if (followLinks == TRUE)
	    chown(destName, srcStatBuf.st_uid, srcStatBuf.st_gid);
	else
	    lchown(destName, srcStatBuf.st_uid, srcStatBuf.st_gid);

	times.actime = srcStatBuf.st_atime;
	times.modtime = srcStatBuf.st_mtime;

	utime(destName, &times);
    }

    return TRUE;


  error_exit:
    perror(destName);
    close(rfd);
    close(wfd);

    return FALSE;
}
#endif



#ifdef BB_TAR
/*
 * Return the standard ls-like mode string from a file mode.
 * This is static and so is overwritten on each call.
 */
const char *modeString(int mode)
{
    static char buf[12];

    strcpy(buf, "----------");

    /*
     * Fill in the file type.
     */
    if (S_ISDIR(mode))
	buf[0] = 'd';
    if (S_ISCHR(mode))
	buf[0] = 'c';
    if (S_ISBLK(mode))
	buf[0] = 'b';
    if (S_ISFIFO(mode))
	buf[0] = 'p';
    if (S_ISLNK(mode))
	buf[0] = 'l';
    if (S_ISSOCK(mode))
	buf[0] = 's';
    /*
     * Now fill in the normal file permissions.
     */
    if (mode & S_IRUSR)
	buf[1] = 'r';
    if (mode & S_IWUSR)
	buf[2] = 'w';
    if (mode & S_IXUSR)
	buf[3] = 'x';
    if (mode & S_IRGRP)
	buf[4] = 'r';
    if (mode & S_IWGRP)
	buf[5] = 'w';
    if (mode & S_IXGRP)
	buf[6] = 'x';
    if (mode & S_IROTH)
	buf[7] = 'r';
    if (mode & S_IWOTH)
	buf[8] = 'w';
    if (mode & S_IXOTH)
	buf[9] = 'x';

    /*
     * Finally fill in magic stuff like suid and sticky text.
     */
    if (mode & S_ISUID)
	buf[3] = ((mode & S_IXUSR) ? 's' : 'S');
    if (mode & S_ISGID)
	buf[6] = ((mode & S_IXGRP) ? 's' : 'S');
    if (mode & S_ISVTX)
	buf[9] = ((mode & S_IXOTH) ? 't' : 'T');

    return buf;
}


/*
 * Get the time string to be used for a file.
 * This is down to the minute for new files, but only the date for old files.
 * The string is returned from a static buffer, and so is overwritten for
 * each call.
 */
const char *timeString(time_t timeVal)
{
    time_t now;
    char *str;
    static char buf[26];

    time(&now);

    str = ctime(&timeVal);

    strcpy(buf, &str[4]);
    buf[12] = '\0';

    if ((timeVal > now) || (timeVal < now - 365 * 24 * 60 * 60L)) {
	strcpy(&buf[7], &str[20]);
	buf[11] = '\0';
    }

    return buf;
}


/*
 * Write all of the supplied buffer out to a file.
 * This does multiple writes as necessary.
 * Returns the amount written, or -1 on an error.
 */
int fullWrite(int fd, const char *buf, int len)
{
    int cc;
    int total;

    total = 0;

    while (len > 0) {
	cc = write(fd, buf, len);

	if (cc < 0)
	    return -1;

	buf += cc;
	total += cc;
	len -= cc;
    }

    return total;
}


/*
 * Read all of the supplied buffer from a file.
 * This does multiple reads as necessary.
 * Returns the amount read, or -1 on an error.
 * A short read is returned on an end of file.
 */
int fullRead(int fd, char *buf, int len)
{
    int cc;
    int total;

    total = 0;

    while (len > 0) {
	cc = read(fd, buf, len);

	if (cc < 0)
	    return -1;

	if (cc == 0)
	    break;

	buf += cc;
	total += cc;
	len -= cc;
    }

    return total;
}
#endif


#if defined (BB_CHOWN) || defined (BB_CP) || defined (BB_FIND) || defined (BB_LS)
/*
 * Walk down all the directories under the specified 
 * location, and do something (something specified
 * by the fileAction and dirAction function pointers).
 *
 * Unfortunatly, while nftw(3) could replace this and reduce 
 * code size a bit, nftw() wasn't supported before GNU libc 2.1, 
 * and so isn't sufficiently portable to take over since glibc2.1
 * is so stinking huge.
 */
int
recursiveAction(const char *fileName, int recurse, int followLinks, int depthFirst,
		int (*fileAction) (const char *fileName, struct stat* statbuf),
		int (*dirAction) (const char *fileName, struct stat* statbuf))
{
    int status;
    struct stat statbuf;
    struct dirent *next;

    if (followLinks == TRUE)
	status = stat(fileName, &statbuf);
    else
	status = lstat(fileName, &statbuf);

    if (status < 0) {
	perror(fileName);
	return (FALSE);
    }

    if ( (followLinks == FALSE) && (S_ISLNK(statbuf.st_mode)) )
	return (TRUE);

    if (recurse == FALSE) {
	if (S_ISDIR(statbuf.st_mode)) {
	    if (dirAction != NULL)
		return (dirAction(fileName, &statbuf));
	    else
		return (TRUE);
	} 
    }

    if (S_ISDIR(statbuf.st_mode)) {
	DIR *dir;
	dir = opendir(fileName);
	if (!dir) {
	    perror(fileName);
	    return (FALSE);
	}
	if (dirAction != NULL && depthFirst == FALSE) {
	    status = dirAction(fileName, &statbuf);
	    if (status == FALSE) {
		perror(fileName);
		return (FALSE);
	    }
	}
	while ((next = readdir(dir)) != NULL) {
	    char nextFile[NAME_MAX];
	    if ((strcmp(next->d_name, "..") == 0)
		|| (strcmp(next->d_name, ".") == 0)) {
		continue;
	    }
	    sprintf(nextFile, "%s/%s", fileName, next->d_name);
	    status =
		recursiveAction(nextFile, TRUE, followLinks, depthFirst, 
			fileAction, dirAction);
	    if (status < 0) {
		closedir(dir);
		return (FALSE);
	    }
	}
	status = closedir(dir);
	if (status < 0) {
	    perror(fileName);
	    return (FALSE);
	}
	if (dirAction != NULL && depthFirst == TRUE) {
	    status = dirAction(fileName, &statbuf);
	    if (status == FALSE) {
		perror(fileName);
		return (FALSE);
	    }
	}
    } else {
	if (fileAction == NULL)
	    return (TRUE);
	else
	    return (fileAction(fileName, &statbuf));
    }
    return (TRUE);
}

#endif



#if defined (BB_TAR) || defined (BB_MKDIR)
/*
 * Attempt to create the directories along the specified path, except for
 * the final component.  The mode is given for the final directory only,
 * while all previous ones get default protections.  Errors are not reported
 * here, as failures to restore files can be reported later.
 */
extern void createPath (const char *name, int mode)
{
    char *cp;
    char *cpOld;
    char buf[NAME_MAX];

    strcpy (buf, name);

    cp = strchr (buf, '/');

    while (cp) {
	cpOld = cp;
	cp = strchr (cp + 1, '/');

	*cpOld = '\0';

	if (mkdir (buf, cp ? 0777 : mode) == 0)
	    printf ("Directory \"%s\" created\n", buf);

	*cpOld = '/';
    }
}
#endif



#if defined (BB_CHMOD_CHOWN_CHGRP) || defined (BB_MKDIR)
/* [ugoa]{+|-|=}[rwxst] */



extern int 
parse_mode( const char* s, mode_t* theMode)
{
	mode_t andMode = S_ISVTX|S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
	mode_t orMode = 0;
	mode_t	mode = 0;
	mode_t	groups = 0;
	char	type;
	char	c;

	do {
		for ( ; ; ) {
			switch ( c = *s++ ) {
			case '\0':
				return -1;
			case 'u':
				groups |= S_ISUID|S_IRWXU;
				continue;
			case 'g':
				groups |= S_ISGID|S_IRWXG;
				continue;
			case 'o':
				groups |= S_IRWXO;
				continue;
			case 'a':
				groups |= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
				continue;
			case '+':
			case '=':
			case '-':
				type = c;
				if ( groups == 0 ) /* The default is "all" */
					groups |= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
				break;
			default:
				if ( isdigit(c) && c >= '0' && c <= '7' && 
						mode == 0 && groups == 0 ) {
					*theMode = strtol(--s, NULL, 8);
					return (TRUE);
				}
				else
					return (FALSE);
			}
			break;
		}

		while ( (c = *s++) != '\0' ) {
			switch ( c ) {
			case ',':
				break;
			case 'r':
				mode |= S_IRUSR|S_IRGRP|S_IROTH;
				continue;
			case 'w':
				mode |= S_IWUSR|S_IWGRP|S_IWOTH;
				continue;
			case 'x':
				mode |= S_IXUSR|S_IXGRP|S_IXOTH;
				continue;
			case 's':
				mode |= S_IXGRP|S_ISUID|S_ISGID;
				continue;
			case 't':
				mode |= 0;
				continue;
			default:
				*theMode &= andMode;
				*theMode |= orMode;
				return( TRUE);
			}
			break;
		}
		switch ( type ) {
		case '=':
			andMode &= ~(groups);
			/* fall through */
		case '+':
			orMode |= mode & groups;
			break;
		case '-':
			andMode &= ~(mode & groups);
			orMode &= andMode;
			break;
		}
	} while ( c == ',' );
	*theMode &= andMode;
	*theMode |= orMode;
	return (TRUE);
}


#endif







#if defined (BB_CHMOD_CHOWN_CHGRP) || defined (BB_PS)

/* Use this to avoid needing the glibc NSS stuff 
 * This uses storage buf to hold things.
 * */
uid_t 
my_getid(const char *filename, char *name, uid_t id) 
{
	FILE *file;
	char *rname, *start, *end, buf[128];
	uid_t rid;

	file=fopen(filename,"r");
	if (file == NULL) {
	    perror(filename);
	    return (-1);
	}

	while (fgets (buf, 128, file) != NULL) {
		if (buf[0] == '#')
			continue;

		start = buf;
		end = strchr (start, ':');
		if (end == NULL)
			continue;
		*end = '\0';
		rname = start;

		start = end + 1;
		end = strchr (start, ':');
		if (end == NULL)
			continue;

		start = end + 1;
		rid = (uid_t) strtol (start, &end, 10);
		if (end == start)
			continue;

		if (name) {
		    if (0 == strcmp(rname, name))
			return( rid);
                }
		if ( id != -1 && id == rid ) {
		    strncpy(name, rname, 8);
		    return( TRUE);
		}
	}
	fclose(file);
	return (-1);
}

uid_t 
my_getpwnam(char *name) 
{
    return my_getid("/etc/passwd", name, -1);
}

gid_t 
my_getgrnam(char *name) 
{
    return my_getid("/etc/group", name, -1);
}

void
my_getpwuid(char* name, uid_t uid) 
{
    my_getid("/etc/passwd", name, uid);
}

void
my_getgrgid(char* group, gid_t gid) 
{
    my_getid("/etc/group", group, gid);
}


#endif




#if (defined BB_CHVT) || (defined BB_DEALLOCVT)


#include <linux/kd.h>
#include <sys/ioctl.h>

int is_a_console(int fd) 
{
  char arg;
  
  arg = 0;
  return (ioctl(fd, KDGKBTYPE, &arg) == 0
	  && ((arg == KB_101) || (arg == KB_84)));
}

static int open_a_console(char *fnam) 
{
  int fd;
  
  /* try read-only */
  fd = open(fnam, O_RDWR);
  
  /* if failed, try read-only */
  if (fd < 0 && errno == EACCES)
      fd = open(fnam, O_RDONLY);
  
  /* if failed, try write-only */
  if (fd < 0 && errno == EACCES)
      fd = open(fnam, O_WRONLY);
  
  /* if failed, fail */
  if (fd < 0)
      return -1;
  
  /* if not a console, fail */
  if (! is_a_console(fd))
    {
      close(fd);
      return -1;
    }
  
  /* success */
  return fd;
}

/*
 * Get an fd for use with kbd/console ioctls.
 * We try several things because opening /dev/console will fail
 * if someone else used X (which does a chown on /dev/console).
 *
 * if tty_name is non-NULL, try this one instead.
 */

int get_console_fd(char* tty_name) 
{
  int fd;

  if (tty_name)
    {
      if (-1 == (fd = open_a_console(tty_name)))
	return -1;
      else
	return fd;
    }
  
  fd = open_a_console("/dev/tty");
  if (fd >= 0)
    return fd;
  
  fd = open_a_console("/dev/tty0");
  if (fd >= 0)
    return fd;
  
  fd = open_a_console("/dev/console");
  if (fd >= 0)
    return fd;
  
  for (fd = 0; fd < 3; fd++)
    if (is_a_console(fd))
      return fd;
  
  fprintf(stderr,
	  "Couldnt get a file descriptor referring to the console\n");
  return -1;		/* total failure */
}


#endif


#if !defined BB_REGEXP && (defined BB_GREP || defined BB_FIND || defined BB_SED)  

/* Do a case insensitive strstr() */
char* stristr(char *haystack, const char *needle)
{
    int len = strlen( needle );
    while( *haystack ) {
	if( !strncasecmp( haystack, needle, len ) )
	    break;
	haystack++;
    }

    if( !(*haystack) )
	    haystack = NULL;

    return haystack;
}

/* This tries to find a needle in a haystack, but does so by
 * only trying to match literal strings (look 'ma, no regexps!)
 * This is short, sweet, and carries _very_ little baggage,
 * unlike its beefier cousin in regexp.c
 *  -Erik Andersen
 */
extern int find_match(char *haystack, char *needle, int ignoreCase)
{

    if (ignoreCase == FALSE)
	haystack = strstr (haystack, needle);
    else
	haystack = stristr (haystack, needle);
    if (haystack == NULL)
	return FALSE;
    return TRUE;
}


/* This performs substitutions after a string match has been found.  */
extern int replace_match(char *haystack, char *needle, char *newNeedle, int ignoreCase)
{
    int foundOne=0;
    char *where, *slider, *slider1, *oldhayStack;

    if (ignoreCase == FALSE)
	where = strstr (haystack, needle);
    else
	where = stristr (haystack, needle);

    if (strcmp(needle, newNeedle)==0)
	return FALSE;

    oldhayStack = (char*)malloc((unsigned)(strlen(haystack)));
    while(where!=NULL) {
	foundOne++;
	strcpy(oldhayStack, haystack);
#if 0
	if ( strlen(newNeedle) > strlen(needle)) {
	    haystack = (char *)realloc(haystack, (unsigned)(strlen(haystack) - 
		strlen(needle) + strlen(newNeedle)));
	}
#endif
	for(slider=haystack,slider1=oldhayStack;slider!=where;slider++,slider1++);
	*slider=0;
	haystack=strcat(haystack, newNeedle);
	slider1+=strlen(needle);
	haystack = strcat(haystack, slider1);
	where = strstr (slider, needle);
    }
    free( oldhayStack);

    if (foundOne > 0)
	return TRUE;
    else
	return FALSE;
}


#endif




#if defined BB_DF | defined BB_MTAB
/*
 * Given a block device, find the mount table entry if that block device
 * is mounted.
 *
 * Given any other file (or directory), find the mount table entry for its
 * filesystem.
 */
extern struct mntent *findMountPoint(const char *name, const char *table)
{
    struct stat s;
    dev_t mountDevice;
    FILE *mountTable;
    struct mntent *mountEntry;

    if (stat(name, &s) != 0)
	return 0;

    if ((s.st_mode & S_IFMT) == S_IFBLK)
	mountDevice = s.st_rdev;
    else
	mountDevice = s.st_dev;


    if ((mountTable = setmntent(table, "r")) == 0)
	return 0;

    while ((mountEntry = getmntent(mountTable)) != 0) {
	if (strcmp(name, mountEntry->mnt_dir) == 0
	    || strcmp(name, mountEntry->mnt_fsname) == 0)	/* String match. */
	    break;
	if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice)	/* Match the device. */
	    break;
	if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice)	/* Match the directory's mount point. */
	    break;
    }
    endmntent(mountTable);
    return mountEntry;
}

#endif



#if !defined BB_MTAB && (defined BB_MOUNT || defined BB_DF )
extern void whine_if_fstab_is_missing()
{
    struct stat statBuf;
    if (stat("/etc/fstab", &statBuf) < 0) 
	fprintf(stderr, "/etc/fstab file missing -- install one to name /dev/root.\n\n");
}
#endif


/* END CODE */