move several applets to more correct ex-project. No code changes.

6 files changed, 65 insertions, 1557 deletions

diff --git a/coreutils/Config.in b/coreutils/Config.in
index be5e9527b..cb5241ef6 100644
--- a/coreutils/Config.in
+++ b/coreutils/Config.in
@@ -65,13 +65,6 @@ config CKSUM
 	help
 	  cksum is used to calculate the CRC32 checksum of a file.
 
-config CMP
-	bool "cmp"
-	default n
-	help
-	  cmp is used to compare two files and returns the result
-	  to standard output.
-
 config COMM
 	bool "comm"
 	default n
@@ -142,38 +135,6 @@ config DF
 	  df reports the amount of disk space used and available
 	  on filesystems.
 
-config DIFF
-	bool "diff"
-	default n
-	help
-	  diff compares two files or directories and outputs the
-	  differences between them in a form that can be given to
-	  the patch command.
-
-config FEATURE_DIFF_BINARY
-	bool "Enable checks for binary files"
-	default y
-	depends on DIFF
-	help
-	  This option enables support for checking for binary files
-	  before a comparison is carried out.
-
-config FEATURE_DIFF_DIR
-	bool "Enable directory support"
-	default y
-	depends on DIFF
-	help
-	  This option enables support for directory and subdirectory
-	  comparison.
-
-config FEATURE_DIFF_MINIMAL
-	bool "Enable -d option to find smaller sets of changes"
-	default n
-	depends on DIFF
-	help
-	  Enabling this option allows the use of -d to make diff
-	  try hard to find the smallest possible set of changes.
-
 config DIRNAME
 	bool "dirname"
 	default n
@@ -474,6 +435,20 @@ config PWD
 	help
 	  pwd is used to print the current directory.
 
+config READLINK
+	bool "readlink"
+	default n
+	help
+	  This program reads a symbolic link and returns the name
+	  of the file it points to
+
+config FEATURE_READLINK_FOLLOW
+	bool "Enable canonicalization by following all symlinks (-f)"
+	default n
+	depends on READLINK
+	help
+	  Enable the readlink option (-f).
+
 config REALPATH
 	bool "realpath"
 	default n
@@ -704,14 +679,6 @@ config UUENCODE
 	help
 	  uuencode is used to uuencode a file.
 
-config WATCH
-	bool "watch"
-	default n
-	select DATE
-	help
-	  watch is used to execute a program periodically, showing
-	  output to the screen.
-
 config WC
 	bool "wc"
 	default n
diff --git a/coreutils/Kbuild b/coreutils/Kbuild
index 1c6e6ed23..fd67d6c85 100644
--- a/coreutils/Kbuild
+++ b/coreutils/Kbuild
@@ -18,14 +18,12 @@ lib-$(CONFIG_CHMOD)     += chmod.o
 lib-$(CONFIG_CHOWN)     += chown.o
 lib-$(CONFIG_CHROOT)    += chroot.o
 lib-$(CONFIG_CKSUM)     += cksum.o
-lib-$(CONFIG_CMP)       += cmp.o
 lib-$(CONFIG_COMM)      += comm.o
 lib-$(CONFIG_CP)        += cp.o
 lib-$(CONFIG_CUT)       += cut.o
 lib-$(CONFIG_DATE)      += date.o
 lib-$(CONFIG_DD)        += dd.o
 lib-$(CONFIG_DF)        += df.o
-lib-$(CONFIG_DIFF)      += diff.o
 lib-$(CONFIG_DIRNAME)   += dirname.o
 lib-$(CONFIG_DOS2UNIX)  += dos2unix.o
 lib-$(CONFIG_DU)        += du.o
@@ -54,6 +52,7 @@ lib-$(CONFIG_OD)        += od.o
 lib-$(CONFIG_PRINTENV)  += printenv.o
 lib-$(CONFIG_PRINTF)    += printf.o
 lib-$(CONFIG_PWD)       += pwd.o
+lib-$(CONFIG_READLINK)  += readlink.o
 lib-$(CONFIG_REALPATH)  += realpath.o
 lib-$(CONFIG_RM)        += rm.o
 lib-$(CONFIG_RMDIR)     += rmdir.o
@@ -79,7 +78,6 @@ lib-$(CONFIG_UNIQ)      += uniq.o
 lib-$(CONFIG_USLEEP)    += usleep.o
 lib-$(CONFIG_UUDECODE)  += uudecode.o
 lib-$(CONFIG_UUENCODE)  += uuencode.o
-lib-$(CONFIG_WATCH)     += watch.o
 lib-$(CONFIG_WC)        += wc.o
 lib-$(CONFIG_WHO)       += who.o
 lib-$(CONFIG_WHOAMI)    += whoami.o
diff --git a/coreutils/cmp.c b/coreutils/cmp.c
deleted file mode 100644
index e5dda80ff..000000000
--- a/coreutils/cmp.c
+++ /dev/null
@@ -1,145 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Mini cmp implementation for busybox
- *
- * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
- */
-
-/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
-/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
-
-/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
- *
- * Original version majorly reworked for SUSv3 compliance, bug fixes, and
- * size optimizations.  Changes include:
- * 1) Now correctly distinguishes between errors and actual file differences.
- * 2) Proper handling of '-' args.
- * 3) Actual error checking of i/o.
- * 4) Accept SUSv3 -l option.  Note that we use the slightly nicer gnu format
- *    in the '-l' case.
- */
-
-#include "libbb.h"
-
-static FILE *cmp_xfopen_input(const char *filename)
-{
-	FILE *fp;
-
-	fp = fopen_or_warn_stdin(filename);
-	if (fp)
-		return fp;
-	xfunc_die();	/* We already output an error message. */
-}
-
-static const char fmt_eof[] = "cmp: EOF on %s\n";
-static const char fmt_differ[] = "%s %s differ: char %"OFF_FMT"d, line %d\n";
-// This fmt_l_opt uses gnu-isms.  SUSv3 would be "%.0s%.0s%"OFF_FMT"d %o %o\n"
-static const char fmt_l_opt[] = "%.0s%.0s%"OFF_FMT"d %3o %3o\n";
-
-static const char opt_chars[] = "sl";
-#define CMP_OPT_s (1<<0)
-#define CMP_OPT_l (1<<1)
-
-int cmp_main(int argc, char **argv);
-int cmp_main(int argc, char **argv)
-{
-	FILE *fp1, *fp2, *outfile = stdout;
-	const char *filename1, *filename2 = "-";
-	USE_DESKTOP(off_t skip1 = 0, skip2 = 0;)
-	off_t char_pos = 0;
-	int line_pos = 1; /* Hopefully won't overflow... */
-	const char *fmt;
-	int c1, c2;
-	unsigned opt;
-	int retval = 0;
-
-	xfunc_error_retval = 2;	/* 1 is returned if files are different. */
-
-	opt_complementary = "?:-1"
-			USE_DESKTOP(":?4")
-			SKIP_DESKTOP(":?2")
-			":l--s:s--l";
-	opt = getopt32(argc, argv, opt_chars);
-	argv += optind;
-
-	filename1 = *argv;
-	fp1 = cmp_xfopen_input(filename1);
-
-	if (*++argv) {
-		filename2 = *argv;
-#if ENABLE_DESKTOP
-		if (*++argv) {
-			skip1 = XATOOFF(*argv);
-			if (*++argv) {
-				skip2 = XATOOFF(*argv);
-			}
-		}
-#endif
-	}
-
-	fp2 = cmp_xfopen_input(filename2);
-	if (fp1 == fp2) {		/* Paranoia check... stdin == stdin? */
-		/* Note that we don't bother reading stdin.  Neither does gnu wc.
-		 * But perhaps we should, so that other apps down the chain don't
-		 * get the input.  Consider 'echo hello | (cmp - - && cat -)'.
-		 */
-		return 0;
-	}
-
-	if (opt & CMP_OPT_l)
-		fmt = fmt_l_opt;
-	else
-		fmt = fmt_differ;
-
-#if ENABLE_DESKTOP
-	while (skip1) { getc(fp1); skip1--; }
-	while (skip2) { getc(fp2); skip2--; }
-#endif
-	do {
-		c1 = getc(fp1);
-		c2 = getc(fp2);
-		++char_pos;
-		if (c1 != c2) {			/* Remember: a read error may have occurred. */
-			retval = 1;		/* But assume the files are different for now. */
-			if (c2 == EOF) {
-				/* We know that fp1 isn't at EOF or in an error state.  But to
-				 * save space below, things are setup to expect an EOF in fp1
-				 * if an EOF occurred.  So, swap things around.
-				 */
-				fp1 = fp2;
-				filename1 = filename2;
-				c1 = c2;
-			}
-			if (c1 == EOF) {
-				die_if_ferror(fp1, filename1);
-				fmt = fmt_eof;	/* Well, no error, so it must really be EOF. */
-				outfile = stderr;
-				/* There may have been output to stdout (option -l), so
-				 * make sure we fflush before writing to stderr. */
-				xfflush_stdout();
-			}
-			if (!(opt & CMP_OPT_s)) {
-				if (opt & CMP_OPT_l) {
-					line_pos = c1;	/* line_pos is unused in the -l case. */
-				}
-				fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
-				if (opt) {	/* This must be -l since not -s. */
-					/* If we encountered an EOF,
-					 * the while check will catch it. */
-					continue;
-				}
-			}
-			break;
-		}
-		if (c1 == '\n') {
-			++line_pos;
-		}
-	} while (c1 != EOF);
-
-	die_if_ferror(fp1, filename1);
-	die_if_ferror(fp2, filename2);
-
-	fflush_stdout_and_exit(retval);
-}
diff --git a/coreutils/diff.c b/coreutils/diff.c
deleted file mode 100644
index 830c15ea6..000000000
--- a/coreutils/diff.c
+++ /dev/null
@@ -1,1282 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Mini diff implementation for busybox, adapted from OpenBSD diff.
- *
- * Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
- * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
- *
- * Sponsored in part by the Defense Advanced Research Projects
- * Agency (DARPA) and Air Force Research Laboratory, Air Force
- * Materiel Command, USAF, under agreement number F39502-99-1-0512.
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
- */
-
-#include "libbb.h"
-
-#define FSIZE_MAX 32768
-
-/*
- * Output flags
- */
-#define D_HEADER        1	/* Print a header/footer between files */
-#define D_EMPTY1        2	/* Treat first file as empty (/dev/null) */
-#define D_EMPTY2        4	/* Treat second file as empty (/dev/null) */
-
-/*
- * Status values for print_status() and diffreg() return values
- * Guide:
- * D_SAME - files are the same
- * D_DIFFER - files differ
- * D_BINARY - binary files differ
- * D_COMMON - subdirectory common to both dirs
- * D_ONLY - file only exists in one dir
- * D_MISMATCH1 - path1 a dir, path2 a file
- * D_MISMATCH2 - path1 a file, path2 a dir
- * D_ERROR - error occurred
- * D_SKIPPED1 - skipped path1 as it is a special file
- * D_SKIPPED2 - skipped path2 as it is a special file
- */
-
-#define D_SAME		0
-#define D_DIFFER	(1<<0)
-#define D_BINARY	(1<<1)
-#define D_COMMON	(1<<2)
-#define D_ONLY		(1<<3)
-#define D_MISMATCH1	(1<<4)
-#define D_MISMATCH2	(1<<5)
-#define D_ERROR		(1<<6)
-#define D_SKIPPED1	(1<<7)
-#define D_SKIPPED2	(1<<8)
-
-/* Command line options */
-#define FLAG_a	(1<<0)
-#define FLAG_b	(1<<1)
-#define FLAG_d  (1<<2)
-#define FLAG_i	(1<<3)
-#define FLAG_L	(1<<4)
-#define FLAG_N	(1<<5)
-#define FLAG_q	(1<<6)
-#define FLAG_r	(1<<7)
-#define FLAG_s	(1<<8)
-#define FLAG_S	(1<<9)
-#define FLAG_t	(1<<10)
-#define FLAG_T	(1<<11)
-#define FLAG_U	(1<<12)
-#define	FLAG_w	(1<<13)
-
-struct cand {
-	int x;
-	int y;
-	int pred;
-};
-
-struct line {
-	int serial;
-	int value;
-};
-
-/*
- * The following struct is used to record change information
- * doing a "context" or "unified" diff.  (see routine "change" to
- * understand the highly mnemonic field names)
- */
-struct context_vec {
-	int a;          /* start line in old file */
-	int b;          /* end line in old file */
-	int c;          /* start line in new file */
-	int d;          /* end line in new file */
-};
-
-struct globals {
-	USE_FEATURE_DIFF_DIR(char **dl;)
-	USE_FEATURE_DIFF_DIR(int dl_count;)
-	/* This is the default number of lines of context. */
-	int context;
-	size_t max_context;
-	int status;
-	char *start;
-	const char *label1;
-	const char *label2;
-	struct line *file[2];
-	int *J;          /* will be overlaid on class */
-	int *class;      /* will be overlaid on file[0] */
-	int *klist;      /* will be overlaid on file[0] after class */
-	int *member;     /* will be overlaid on file[1] */
-	int clen;
-	int len[2];
-	int pref, suff;  /* length of prefix and suffix */
-	int slen[2];
-	bool anychange;
-	long *ixnew;     /* will be overlaid on file[1] */
-	long *ixold;     /* will be overlaid on klist */
-	struct cand *clist;  /* merely a free storage pot for candidates */
-	int clistlen;    /* the length of clist */
-	struct line *sfile[2];   /* shortened by pruning common prefix/suffix */
-	struct context_vec *context_vec_start;
-	struct context_vec *context_vec_end;
-	struct context_vec *context_vec_ptr;
-	struct stat stb1, stb2;
-};
-#define G (*ptr_to_globals)
-#define dl                 (G.dl                )
-#define dl_count           (G.dl_count          )
-#define context            (G.context           )
-#define max_context        (G.max_context       )
-#define status             (G.status            )
-#define start              (G.start             )
-#define label1             (G.label1            )
-#define label2             (G.label2            )
-#define file               (G.file              )
-#define J                  (G.J                 )
-#define class              (G.class             )
-#define klist              (G.klist             )
-#define member             (G.member            )
-#define clen               (G.clen              )
-#define len                (G.len               )
-#define pref               (G.pref              )
-#define suff               (G.suff              )
-#define slen               (G.slen              )
-#define anychange          (G.anychange         )
-#define ixnew              (G.ixnew             )
-#define ixold              (G.ixold             )
-#define clist              (G.clist             )
-#define clistlen           (G.clistlen          )
-#define sfile              (G.sfile             )
-#define context_vec_start  (G.context_vec_start )
-#define context_vec_end    (G.context_vec_end   )
-#define context_vec_ptr    (G.context_vec_ptr   )
-#define stb1               (G.stb1              )
-#define stb2               (G.stb2              )
-#define INIT_G() do { \
-	PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
-	context = 3; \
-	max_context = 64; \
-} while (0)
-
-
-static void print_only(const char *path, size_t dirlen, const char *entry)
-{
-	if (dirlen > 1)
-		dirlen--;
-	printf("Only in %.*s: %s\n", (int) dirlen, path, entry);
-}
-
-static void print_status(int val, char *path1, char *path2, char *entry)
-{
-	const char * const _entry = entry ? entry : "";
-	char * const _path1 = entry ? concat_path_file(path1, _entry) : path1;
-	char * const _path2 = entry ? concat_path_file(path2, _entry) : path2;
-
-	switch (val) {
-	case D_ONLY:
-		print_only(path1, strlen(path1), entry);
-		break;
-	case D_COMMON:
-		printf("Common subdirectories: %s and %s\n", _path1, _path2);
-		break;
-	case D_BINARY:
-		printf("Binary files %s and %s differ\n", _path1, _path2);
-		break;
-	case D_DIFFER:
-		if (option_mask32 & FLAG_q)
-			printf("Files %s and %s differ\n", _path1, _path2);
-		break;
-	case D_SAME:
-		if (option_mask32 & FLAG_s)
-			printf("Files %s and %s are identical\n", _path1, _path2);
-		break;
-	case D_MISMATCH1:
-		printf("File %s is a %s while file %s is a %s\n",
-			   _path1, "directory", _path2, "regular file");
-		break;
-	case D_MISMATCH2:
-		printf("File %s is a %s while file %s is a %s\n",
-			   _path1, "regular file", _path2, "directory");
-		break;
-	case D_SKIPPED1:
-		printf("File %s is not a regular file or directory and was skipped\n",
-			   _path1);
-		break;
-	case D_SKIPPED2:
-		printf("File %s is not a regular file or directory and was skipped\n",
-			   _path2);
-		break;
-	}
-	if (entry) {
-		free(_path1);
-		free(_path2);
-	}
-}
-static void fiddle_sum(int *sum, int t)
-{
-	*sum = (int)(*sum * 127 + t);
-}
-/*
- * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
- */
-static int readhash(FILE * f)
-{
-	int i, t, space;
-	int sum;
-
-	sum = 1;
-	space = 0;
-	if (!(option_mask32 & (FLAG_b | FLAG_w))) {
-		for (i = 0; (t = getc(f)) != '\n'; i++) {
-			if (t == EOF) {
-				if (i == 0)
-					return 0;
-				break;
-			}
-			fiddle_sum(&sum, t);
-		}
-	} else {
-		for (i = 0;;) {
-			switch (t = getc(f)) {
-			case '\t':
-			case '\r':
-			case '\v':
-			case '\f':
-			case ' ':
-				space++;
-				continue;
-			default:
-				if (space && !(option_mask32 & FLAG_w)) {
-					i++;
-					space = 0;
-				}
-				fiddle_sum(&sum, t);
-				i++;
-				continue;
-			case EOF:
-				if (i == 0)
-					return 0;
-				/* FALLTHROUGH */
-			case '\n':
-				break;
-			}
-			break;
-		}
-	}
-	/*
-	 * There is a remote possibility that we end up with a zero sum.
-	 * Zero is used as an EOF marker, so return 1 instead.
-	 */
-	return (sum == 0 ? 1 : sum);
-}
-
-
-/*
- * Check to see if the given files differ.
- * Returns 0 if they are the same, 1 if different, and -1 on error.
- */
-static int files_differ(FILE * f1, FILE * f2, int flags)
-{
-	size_t i, j;
-
-	if ((flags & (D_EMPTY1 | D_EMPTY2)) || stb1.st_size != stb2.st_size
-	 || (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT)
-	) {
-		return 1;
-	}
-	while (1) {
-		i = fread(bb_common_bufsiz1,            1, BUFSIZ/2, f1);
-		j = fread(bb_common_bufsiz1 + BUFSIZ/2, 1, BUFSIZ/2, f2);
-		if (i != j)
-			return 1;
-		if (i == 0)
-			return (ferror(f1) || ferror(f2));
-		if (memcmp(bb_common_bufsiz1,
-		           bb_common_bufsiz1 + BUFSIZ/2, i) != 0)
-			return 1;
-	}
-}
-
-
-static void prepare(int i, FILE * fd, off_t filesize)
-{
-	struct line *p;
-	int h;
-	size_t j, sz;
-
-	rewind(fd);
-
-	sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;
-	if (sz < 100)
-		sz = 100;
-
-	p = xmalloc((sz + 3) * sizeof(struct line));
-	j = 0;
-	while ((h = readhash(fd))) {
-		if (j == sz) {
-			sz = sz * 3 / 2;
-			p = xrealloc(p, (sz + 3) * sizeof(struct line));
-		}
-		p[++j].value = h;
-	}
-	len[i] = j;
-	file[i] = p;
-}
-
-
-static void prune(void)
-{
-	int i, j;
-
-	for (pref = 0; pref < len[0] && pref < len[1] &&
-		 file[0][pref + 1].value == file[1][pref + 1].value; pref++)
-		 ;
-	for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
-		 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
-		 suff++)
-		 ;
-	for (j = 0; j < 2; j++) {
-		sfile[j] = file[j] + pref;
-		slen[j] = len[j] - pref - suff;
-		for (i = 0; i <= slen[j]; i++)
-			sfile[j][i].serial = i;
-	}
-}
-
-
-static void equiv(struct line *a, int n, struct line *b, int m, int *c)
-{
-	int i, j;
-
-	i = j = 1;
-	while (i <= n && j <= m) {
-		if (a[i].value < b[j].value)
-			a[i++].value = 0;
-		else if (a[i].value == b[j].value)
-			a[i++].value = j;
-		else
-			j++;
-	}
-	while (i <= n)
-		a[i++].value = 0;
-	b[m + 1].value = 0;
-	j = 0;
-	while (++j <= m) {
-		c[j] = -b[j].serial;
-		while (b[j + 1].value == b[j].value) {
-			j++;
-			c[j] = b[j].serial;
-		}
-	}
-	c[j] = -1;
-}
-
-
-static int isqrt(int n)
-{
-	int y, x;
-
-	if (n == 0)
-		return 0;
-	x = 1;
-	do {
-		y = x;
-		x = n / x;
-		x += y;
-		x /= 2;
-	} while ((x - y) > 1 || (x - y) < -1);
-
-	return x;
-}
-
-
-static int newcand(int x, int y, int pred)
-{
-	struct cand *q;
-
-	if (clen == clistlen) {
-		clistlen = clistlen * 11 / 10;
-		clist = xrealloc(clist, clistlen * sizeof(struct cand));
-	}
-	q = clist + clen;
-	q->x = x;
-	q->y = y;
-	q->pred = pred;
-	return clen++;
-}
-
-
-static int search(int *c, int k, int y)
-{
-	int i, j, l, t;
-
-	if (clist[c[k]].y < y)	/* quick look for typical case */
-		return k + 1;
-	i = 0;
-	j = k + 1;
-	while (1) {
-		l = i + j;
-		if ((l >>= 1) <= i)
-			break;
-		t = clist[c[l]].y;
-		if (t > y)
-			j = l;
-		else if (t < y)
-			i = l;
-		else
-			return l;
-	}
-	return l + 1;
-}
-
-
-static int stone(int *a, int n, int *b, int *c)
-{
-	int i, k, y, j, l;
-	int oldc, tc, oldl;
-	unsigned int numtries;
-
-#if ENABLE_FEATURE_DIFF_MINIMAL
-	const unsigned int bound =
-		(option_mask32 & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
-#else
-	const unsigned int bound = MAX(256, isqrt(n));
-#endif
-	k = 0;
-	c[0] = newcand(0, 0, 0);
-	for (i = 1; i <= n; i++) {
-		j = a[i];
-		if (j == 0)
-			continue;
-		y = -b[j];
-		oldl = 0;
-		oldc = c[0];
-		numtries = 0;
-		do {
-			if (y <= clist[oldc].y)
-				continue;
-			l = search(c, k, y);
-			if (l != oldl + 1)
-				oldc = c[l - 1];
-			if (l <= k) {
-				if (clist[c[l]].y <= y)
-					continue;
-				tc = c[l];
-				c[l] = newcand(i, y, oldc);
-				oldc = tc;
-				oldl = l;
-				numtries++;
-			} else {
-				c[l] = newcand(i, y, oldc);
-				k++;
-				break;
-			}
-		} while ((y = b[++j]) > 0 && numtries < bound);
-	}
-	return k;
-}
-
-
-static void unravel(int p)
-{
-	struct cand *q;
-	int i;
-
-	for (i = 0; i <= len[0]; i++)
-		J[i] = i <= pref ? i : i > len[0] - suff ? i + len[1] - len[0] : 0;
-	for (q = clist + p; q->y != 0; q = clist + q->pred)
-		J[q->x + pref] = q->y + pref;
-}
-
-
-static void unsort(struct line *f, int l, int *b)
-{
-	int *a, i;
-
-	a = xmalloc((l + 1) * sizeof(int));
-	for (i = 1; i <= l; i++)
-		a[f[i].serial] = f[i].value;
-	for (i = 1; i <= l; i++)
-		b[i] = a[i];
-	free(a);
-}
-
-
-static int skipline(FILE * f)
-{
-	int i, c;
-
-	for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
-		continue;
-	return i;
-}
-
-
-/*
- * Check does double duty:
- *  1.  ferret out any fortuitous correspondences due
- *      to confounding by hashing (which result in "jackpot")
- *  2.  collect random access indexes to the two files
- */
-static void check(FILE * f1, FILE * f2)
-{
-	int i, j, jackpot, c, d;
-	long ctold, ctnew;
-
-	rewind(f1);
-	rewind(f2);
-	j = 1;
-	ixold[0] = ixnew[0] = 0;
-	jackpot = 0;
-	ctold = ctnew = 0;
-	for (i = 1; i <= len[0]; i++) {
-		if (J[i] == 0) {
-			ixold[i] = ctold += skipline(f1);
-			continue;
-		}
-		while (j < J[i]) {
-			ixnew[j] = ctnew += skipline(f2);
-			j++;
-		}
-		if ((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)
-			|| (option_mask32 & FLAG_i)) {
-			while (1) {
-				c = getc(f1);
-				d = getc(f2);
-				/*
-				 * GNU diff ignores a missing newline
-				 * in one file if bflag || wflag.
-				 */
-				if (((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)) &&
-					((c == EOF && d == '\n') || (c == '\n' && d == EOF))) {
-					break;
-				}
-				ctold++;
-				ctnew++;
-				if ((option_mask32 & FLAG_b) && isspace(c) && isspace(d)) {
-					do {
-						if (c == '\n')
-							break;
-						ctold++;
-					} while (isspace(c = getc(f1)));
-					do {
-						if (d == '\n')
-							break;
-						ctnew++;
-					} while (isspace(d = getc(f2)));
-				} else if (option_mask32 & FLAG_w) {
-					while (isspace(c) && c != '\n') {
-						c = getc(f1);
-						ctold++;
-					}
-					while (isspace(d) && d != '\n') {
-						d = getc(f2);
-						ctnew++;
-					}
-				}
-				if (c != d) {
-					jackpot++;
-					J[i] = 0;
-					if (c != '\n' && c != EOF)
-						ctold += skipline(f1);
-					if (d != '\n' && c != EOF)
-						ctnew += skipline(f2);
-					break;
-				}
-				if (c == '\n' || c == EOF)
-					break;
-			}
-		} else {
-			while (1) {
-				ctold++;
-				ctnew++;
-				if ((c = getc(f1)) != (d = getc(f2))) {
-					J[i] = 0;
-					if (c != '\n' && c != EOF)
-						ctold += skipline(f1);
-					if (d != '\n' && c != EOF)
-						ctnew += skipline(f2);
-					break;
-				}
-				if (c == '\n' || c == EOF)
-					break;
-			}
-		}
-		ixold[i] = ctold;
-		ixnew[j] = ctnew;
-		j++;
-	}
-	for (; j <= len[1]; j++)
-		ixnew[j] = ctnew += skipline(f2);
-}
-
-
-/* shellsort CACM #201 */
-static void sort(struct line *a, int n)
-{
-	struct line *ai, *aim, w;
-	int j, m = 0, k;
-
-	if (n == 0)
-		return;
-	for (j = 1; j <= n; j *= 2)
-		m = 2 * j - 1;
-	for (m /= 2; m != 0; m /= 2) {
-		k = n - m;
-		for (j = 1; j <= k; j++) {
-			for (ai = &a[j]; ai > a; ai -= m) {
-				aim = &ai[m];
-				if (aim < ai)
-					break;	/* wraparound */
-				if (aim->value > ai[0].value ||
-					(aim->value == ai[0].value && aim->serial > ai[0].serial))
-					break;
-				w.value = ai[0].value;
-				ai[0].value = aim->value;
-				aim->value = w.value;
-				w.serial = ai[0].serial;
-				ai[0].serial = aim->serial;
-				aim->serial = w.serial;
-			}
-		}
-	}
-}
-
-
-static void uni_range(int a, int b)
-{
-	if (a < b)
-		printf("%d,%d", a, b - a + 1);
-	else if (a == b)
-		printf("%d", b);
-	else
-		printf("%d,0", b);
-}
-
-
-static void fetch(long *f, int a, int b, FILE * lb, int ch)
-{
-	int i, j, c, lastc, col, nc;
-
-	if (a > b)
-		return;
-	for (i = a; i <= b; i++) {
-		fseek(lb, f[i - 1], SEEK_SET);
-		nc = f[i] - f[i - 1];
-		if (ch != '\0') {
-			putchar(ch);
-			if (option_mask32 & FLAG_T)
-				putchar('\t');
-		}
-		col = 0;
-		for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
-			if ((c = getc(lb)) == EOF) {
-				printf("\n\\ No newline at end of file\n");
-				return;
-			}
-			if (c == '\t' && (option_mask32 & FLAG_t)) {
-				do {
-					putchar(' ');
-				} while (++col & 7);
-			} else {
-				putchar(c);
-				col++;
-			}
-		}
-	}
-}
-
-
-static int asciifile(FILE * f)
-{
-#if ENABLE_FEATURE_DIFF_BINARY
-	int i, cnt;
-#endif
-
-	if ((option_mask32 & FLAG_a) || f == NULL)
-		return 1;
-
-#if ENABLE_FEATURE_DIFF_BINARY
-	rewind(f);
-	cnt = fread(bb_common_bufsiz1, 1, BUFSIZ, f);
-	for (i = 0; i < cnt; i++) {
-		if (!isprint(bb_common_bufsiz1[i])
-		 && !isspace(bb_common_bufsiz1[i])) {
-			return 0;
-		}
-	}
-#endif
-	return 1;
-}
-
-
-/* dump accumulated "unified" diff changes */
-static void dump_unified_vec(FILE * f1, FILE * f2)
-{
-	struct context_vec *cvp = context_vec_start;
-	int lowa, upb, lowc, upd;
-	int a, b, c, d;
-	char ch;
-
-	if (context_vec_start > context_vec_ptr)
-		return;
-
-	b = d = 0;			/* gcc */
-	lowa = MAX(1, cvp->a - context);
-	upb = MIN(len[0], context_vec_ptr->b + context);
-	lowc = MAX(1, cvp->c - context);
-	upd = MIN(len[1], context_vec_ptr->d + context);
-
-	printf("@@ -");
-	uni_range(lowa, upb);
-	printf(" +");
-	uni_range(lowc, upd);
-	printf(" @@\n");
-
-	/*
-	 * Output changes in "unified" diff format--the old and new lines
-	 * are printed together.
-	 */
-	for (; cvp <= context_vec_ptr; cvp++) {
-		a = cvp->a;
-		b = cvp->b;
-		c = cvp->c;
-		d = cvp->d;
-
-		/*
-		 * c: both new and old changes
-		 * d: only changes in the old file
-		 * a: only changes in the new file
-		 */
-		if (a <= b && c <= d)
-			ch = 'c';
-		else
-			ch = (a <= b) ? 'd' : 'a';
-#if 0
-		switch (ch) {
-		case 'c':
-			fetch(ixold, lowa, a - 1, f1, ' ');
-			fetch(ixold, a, b, f1, '-');
-			fetch(ixnew, c, d, f2, '+');
-			break;
-		case 'd':
-			fetch(ixold, lowa, a - 1, f1, ' ');
-			fetch(ixold, a, b, f1, '-');
-			break;
-		case 'a':
-			fetch(ixnew, lowc, c - 1, f2, ' ');
-			fetch(ixnew, c, d, f2, '+');
-			break;
-		}
-#else
-		if (ch == 'c' || ch == 'd') {
-			fetch(ixold, lowa, a - 1, f1, ' ');
-			fetch(ixold, a, b, f1, '-');
-		}
-		if (ch == 'a')
-			fetch(ixnew, lowc, c - 1, f2, ' ');
-		if (ch == 'c' || ch == 'a')
-			fetch(ixnew, c, d, f2, '+');
-#endif
-		lowa = b + 1;
-		lowc = d + 1;
-	}
-	fetch(ixnew, d + 1, upd, f2, ' ');
-
-	context_vec_ptr = context_vec_start - 1;
-}
-
-
-static void print_header(const char *file1, const char *file2)
-{
-	if (label1)
-		printf("--- %s\n", label1);
-	else
-		printf("--- %s\t%s", file1, ctime(&stb1.st_mtime));
-	if (label2)
-		printf("+++ %s\n", label2);
-	else
-		printf("+++ %s\t%s", file2, ctime(&stb2.st_mtime));
-}
-
-
-/*
- * Indicate that there is a difference between lines a and b of the from file
- * to get to lines c to d of the to file.  If a is greater than b then there
- * are no lines in the from file involved and this means that there were
- * lines appended (beginning at b).  If c is greater than d then there are
- * lines missing from the to file.
- */
-static void change(char *file1, FILE * f1, char *file2, FILE * f2, int a,
-				   int b, int c, int d)
-{
-	if ((a > b && c > d) || (option_mask32 & FLAG_q)) {
-		anychange = 1;
-		return;
-	}
-
-	/*
-	 * Allocate change records as needed.
-	 */
-	if (context_vec_ptr == context_vec_end - 1) {
-		ptrdiff_t offset = context_vec_ptr - context_vec_start;
-
-		max_context <<= 1;
-		context_vec_start = xrealloc(context_vec_start,
-				max_context * sizeof(struct context_vec));
-		context_vec_end = context_vec_start + max_context;
-		context_vec_ptr = context_vec_start + offset;
-	}
-	if (anychange == 0) {
-		/*
-		 * Print the context/unidiff header first time through.
-		 */
-		print_header(file1, file2);
-	} else if (a > context_vec_ptr->b + (2 * context) + 1 &&
-			   c > context_vec_ptr->d + (2 * context) + 1) {
-		/*
-		 * If this change is more than 'context' lines from the
-		 * previous change, dump the record and reset it.
-		 */
-		dump_unified_vec(f1, f2);
-	}
-	context_vec_ptr++;
-	context_vec_ptr->a = a;
-	context_vec_ptr->b = b;
-	context_vec_ptr->c = c;
-	context_vec_ptr->d = d;
-	anychange = 1;
-}
-
-
-static void output(char *file1, FILE * f1, char *file2, FILE * f2)
-{
-	/* Note that j0 and j1 can't be used as they are defined in math.h.
-	 * This also allows the rather amusing variable 'j00'... */
-	int m, i0, i1, j00, j01;
-
-	rewind(f1);
-	rewind(f2);
-	m = len[0];
-	J[0] = 0;
-	J[m + 1] = len[1] + 1;
-	for (i0 = 1; i0 <= m; i0 = i1 + 1) {
-		while (i0 <= m && J[i0] == J[i0 - 1] + 1)
-			i0++;
-		j00 = J[i0 - 1] + 1;
-		i1 = i0 - 1;
-		while (i1 < m && J[i1 + 1] == 0)
-			i1++;
-		j01 = J[i1 + 1] - 1;
-		J[i1] = j01;
-		change(file1, f1, file2, f2, i0, i1, j00, j01);
-	}
-	if (m == 0) {
-		change(file1, f1, file2, f2, 1, 0, 1, len[1]);
-	}
-	if (anychange != 0 && !(option_mask32 & FLAG_q)) {
-		dump_unified_vec(f1, f2);
-	}
-}
-
-/*
- * The following code uses an algorithm due to Harold Stone,
- * which finds a pair of longest identical subsequences in
- * the two files.
- *
- * The major goal is to generate the match vector J.
- * J[i] is the index of the line in file1 corresponding
- * to line i file0. J[i] = 0 if there is no
- * such line in file1.
- *
- * Lines are hashed so as to work in core. All potential
- * matches are located by sorting the lines of each file
- * on the hash (called ``value''). In particular, this
- * collects the equivalence classes in file1 together.
- * Subroutine equiv replaces the value of each line in
- * file0 by the index of the first element of its
- * matching equivalence in (the reordered) file1.
- * To save space equiv squeezes file1 into a single
- * array member in which the equivalence classes
- * are simply concatenated, except that their first
- * members are flagged by changing sign.
- *
- * Next the indices that point into member are unsorted into
- * array class according to the original order of file0.
- *
- * The cleverness lies in routine stone. This marches
- * through the lines of file0, developing a vector klist
- * of "k-candidates". At step i a k-candidate is a matched
- * pair of lines x,y (x in file0 y in file1) such that
- * there is a common subsequence of length k
- * between the first i lines of file0 and the first y
- * lines of file1, but there is no such subsequence for
- * any smaller y. x is the earliest possible mate to y
- * that occurs in such a subsequence.
- *
- * Whenever any of the members of the equivalence class of
- * lines in file1 matable to a line in file0 has serial number
- * less than the y of some k-candidate, that k-candidate
- * with the smallest such y is replaced. The new
- * k-candidate is chained (via pred) to the current
- * k-1 candidate so that the actual subsequence can
- * be recovered. When a member has serial number greater
- * that the y of all k-candidates, the klist is extended.
- * At the end, the longest subsequence is pulled out
- * and placed in the array J by unravel
- *
- * With J in hand, the matches there recorded are
- * checked against reality to assure that no spurious
- * matches have crept in due to hashing. If they have,
- * they are broken, and "jackpot" is recorded--a harmless
- * matter except that a true match for a spuriously
- * mated line may now be unnecessarily reported as a change.
- *
- * Much of the complexity of the program comes simply
- * from trying to minimize core utilization and
- * maximize the range of doable problems by dynamically
- * allocating what is needed and reusing what is not.
- * The core requirements for problems larger than somewhat
- * are (in words) 2*length(file0) + length(file1) +
- * 3*(number of k-candidates installed),  typically about
- * 6n words for files of length n.
- */
-static unsigned diffreg(char * ofile1, char * ofile2, int flags)
-{
-	char *file1 = ofile1;
-	char *file2 = ofile2;
-	FILE *f1 = stdin, *f2 = stdin;
-	unsigned rval;
-	int i;
-
-	anychange = 0;
-	context_vec_ptr = context_vec_start - 1;
-
-	if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
-		return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
-
-	rval = D_SAME;
-
-	if (LONE_DASH(file1) && LONE_DASH(file2))
-		goto closem;
-
-	if (flags & D_EMPTY1)
-		f1 = xfopen(bb_dev_null, "r");
-	else if (NOT_LONE_DASH(file1))
-		f1 = xfopen(file1, "r");
-	if (flags & D_EMPTY2)
-		f2 = xfopen(bb_dev_null, "r");
-	else if (NOT_LONE_DASH(file2))
-		f2 = xfopen(file2, "r");
-
-/* We can't diff non-seekable stream - we use rewind(), fseek().
- * This can be fixed (volunteers?).
- * Meanwhile we should check it here by stat'ing input fds,
- * but I am lazy and check that in main() instead.
- * Check in main won't catch "diffing fifos buried in subdirectories"
- * failure scenario - not very likely in real life... */
-
-	i = files_differ(f1, f2, flags);
-	if (i == 0)
-		goto closem;
-	else if (i != 1) {	/* 1 == ok */
-		/* error */
-		status |= 2;
-		goto closem;
-	}
-
-	if (!asciifile(f1) || !asciifile(f2)) {
-		rval = D_BINARY;
-		status |= 1;
-		goto closem;
-	}
-
-	prepare(0, f1, stb1.st_size);
-	prepare(1, f2, stb2.st_size);
-	prune();
-	sort(sfile[0], slen[0]);
-	sort(sfile[1], slen[1]);
-
-	member = (int *) file[1];
-	equiv(sfile[0], slen[0], sfile[1], slen[1], member);
-	member = xrealloc(member, (slen[1] + 2) * sizeof(int));
-
-	class = (int *) file[0];
-	unsort(sfile[0], slen[0], class);
-	class = xrealloc(class, (slen[0] + 2) * sizeof(int));
-
-	klist = xmalloc((slen[0] + 2) * sizeof(int));
-	clen = 0;
-	clistlen = 100;
-	clist = xmalloc(clistlen * sizeof(struct cand));
-	i = stone(class, slen[0], member, klist);
-	free(member);
-	free(class);
-
-	J = xrealloc(J, (len[0] + 2) * sizeof(int));
-	unravel(klist[i]);
-	free(clist);
-	free(klist);
-
-	ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
-	ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
-	check(f1, f2);
-	output(file1, f1, file2, f2);
-
- closem:
-	if (anychange) {
-		status |= 1;
-		if (rval == D_SAME)
-			rval = D_DIFFER;
-	}
-	fclose_if_not_stdin(f1);
-	fclose_if_not_stdin(f2);
-	if (file1 != ofile1)
-		free(file1);
-	if (file2 != ofile2)
-		free(file2);
-	return rval;
-}
-
-
-#if ENABLE_FEATURE_DIFF_DIR
-static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
-{
-	int flags = D_HEADER;
-	int val;
-	char *fullpath1 = NULL; /* if -N */
-	char *fullpath2 = NULL;
-
-	if (path1)
-		fullpath1 = concat_path_file(dir1, path1);
-	if (path2)
-		fullpath2 = concat_path_file(dir2, path2);
-
-	if (!fullpath1 || stat(fullpath1, &stb1) != 0) {
-		flags |= D_EMPTY1;
-		memset(&stb1, 0, sizeof(stb1));
-		if (path2) {
-			free(fullpath1);
-			fullpath1 = concat_path_file(dir1, path2);
-		}
-	}
-	if (!fullpath2 || stat(fullpath2, &stb2) != 0) {
-		flags |= D_EMPTY2;
-		memset(&stb2, 0, sizeof(stb2));
-		stb2.st_mode = stb1.st_mode;
-		if (path1) {
-			free(fullpath2);
-			fullpath2 = concat_path_file(dir2, path1);
-		}
-	}
-
-	if (stb1.st_mode == 0)
-		stb1.st_mode = stb2.st_mode;
-
-	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
-		printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
-		goto ret;
-	}
-
-	if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
-		val = D_SKIPPED1;
-	else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
-		val = D_SKIPPED2;
-	else
-		val = diffreg(fullpath1, fullpath2, flags);
-
-	print_status(val, fullpath1, fullpath2, NULL);
- ret:
-	free(fullpath1);
-	free(fullpath2);
-}
-#endif
-
-
-#if ENABLE_FEATURE_DIFF_DIR
-static int dir_strcmp(const void *p1, const void *p2)
-{
-	return strcmp(*(char *const *) p1, *(char *const *) p2);
-}
-
-
-/* This function adds a filename to dl, the directory listing. */
-static int add_to_dirlist(const char *filename,
-		struct stat ATTRIBUTE_UNUSED * sb, void *userdata,
-		int depth ATTRIBUTE_UNUSED)
-{
-	/* +2: with space for eventual trailing NULL */
-	dl = xrealloc(dl, (dl_count+2) * sizeof(dl[0]));
-	dl[dl_count] = xstrdup(filename + (int)(ptrdiff_t)userdata);
-	dl_count++;
-	return TRUE;
-}
-
-
-/* This returns a sorted directory listing. */
-static char **get_dir(char *path)
-{
-	dl_count = 0;
-	dl = xzalloc(sizeof(dl[0]));
-
-	/* If -r has been set, then the recursive_action function will be
-	 * used. Unfortunately, this outputs the root directory along with
-	 * the recursed paths, so use void *userdata to specify the string
-	 * length of the root directory - '(void*)(strlen(path)+)'.
-	 * add_to_dirlist then removes root dir prefix. */
-
-	if (option_mask32 & FLAG_r) {
-		recursive_action(path, ACTION_RECURSE|ACTION_FOLLOWLINKS,
-					add_to_dirlist, NULL,
-					(void*)(strlen(path)+1), 0);
-	} else {
-		DIR *dp;
-		struct dirent *ep;
-
-		dp = warn_opendir(path);
-		while ((ep = readdir(dp))) {
-			if (!strcmp(ep->d_name, "..") || LONE_CHAR(ep->d_name, '.'))
-				continue;
-			add_to_dirlist(ep->d_name, NULL, (void*)(int)0, 0);
-		}
-		closedir(dp);
-	}
-
-	/* Sort dl alphabetically. */
-	qsort(dl, dl_count, sizeof(char *), dir_strcmp);
-
-	dl[dl_count] = NULL;
-	return dl;
-}
-
-
-static void diffdir(char *p1, char *p2)
-{
-	char **dirlist1, **dirlist2;
-	char *dp1, *dp2;
-	int pos;
-
-	/* Check for trailing slashes. */
-	dp1 = last_char_is(p1, '/');
-	if (dp1 != NULL)
-		*dp1 = '\0';
-	dp2 = last_char_is(p2, '/');
-	if (dp2 != NULL)
-		*dp2 = '\0';
-
-	/* Get directory listings for p1 and p2. */
-
-	dirlist1 = get_dir(p1);
-	dirlist2 = get_dir(p2);
-
-	/* If -S was set, find the starting point. */
-	if (start) {
-		while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
-			dirlist1++;
-		while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
-			dirlist2++;
-		if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
-			bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
-	}
-
-	/* Now that both dirlist1 and dirlist2 contain sorted directory
-	 * listings, we can start to go through dirlist1. If both listings
-	 * contain the same file, then do a normal diff. Otherwise, behaviour
-	 * is determined by whether the -N flag is set. */
-	while (*dirlist1 != NULL || *dirlist2 != NULL) {
-		dp1 = *dirlist1;
-		dp2 = *dirlist2;
-		pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
-		if (pos == 0) {
-			do_diff(p1, dp1, p2, dp2);
-			dirlist1++;
-			dirlist2++;
-		} else if (pos < 0) {
-			if (option_mask32 & FLAG_N)
-				do_diff(p1, dp1, p2, NULL);
-			else
-				print_only(p1, strlen(p1) + 1, dp1);
-			dirlist1++;
-		} else {
-			if (option_mask32 & FLAG_N)
-				do_diff(p1, NULL, p2, dp2);
-			else
-				print_only(p2, strlen(p2) + 1, dp2);
-			dirlist2++;
-		}
-	}
-}
-#endif
-
-
-int diff_main(int argc, char **argv);
-int diff_main(int argc, char **argv)
-{
-	bool gotstdin = 0;
-	char *U_opt;
-	char *f1, *f2;
-	llist_t *L_arg = NULL;
-
-	INIT_G();
-
-	/* exactly 2 params; collect multiple -L <label> */
-	opt_complementary = "=2:L::";
-	getopt32(argc, argv, "abdiL:NqrsS:tTU:wu"
-			"p" /* ignored (for compatibility) */,
-			&L_arg, &start, &U_opt);
-	/*argc -= optind;*/
-	argv += optind;
-	while (L_arg) {
-		if (label1 && label2)
-			bb_show_usage();
-		if (!label1)
-			label1 = L_arg->data;
-		else { /* then label2 is NULL */
-			label2 = label1;
-			label1 = L_arg->data;
-		}
-		/* we leak L_arg here... */
-		L_arg = L_arg->link;
-	}
-	if (option_mask32 & FLAG_U)
-		context = xatoi_u(U_opt);
-
-	/*
-	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
-	 * driver routine.  Both drivers use the contents of stb1 and stb2.
-	 */
-
-	f1 = argv[0];
-	f2 = argv[1];
-	if (LONE_DASH(f1)) {
-		fstat(STDIN_FILENO, &stb1);
-		gotstdin = 1;
-	} else
-		xstat(f1, &stb1);
-	if (LONE_DASH(f2)) {
-		fstat(STDIN_FILENO, &stb2);
-		gotstdin = 1;
-	} else
-		xstat(f2, &stb2);
-	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
-		bb_error_msg_and_die("can't compare - to a directory");
-	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
-#if ENABLE_FEATURE_DIFF_DIR
-		diffdir(f1, f2);
-#else
-		bb_error_msg_and_die("directory comparison not supported");
-#endif
-	} else {
-		if (S_ISDIR(stb1.st_mode)) {
-			f1 = concat_path_file(f1, f2);
-			xstat(f1, &stb1);
-		}
-		if (S_ISDIR(stb2.st_mode)) {
-			f2 = concat_path_file(f2, f1);
-			xstat(f2, &stb2);
-		}
-/* XXX: FIXME: */
-/* We can't diff e.g. stdin supplied by a pipe - we use rewind(), fseek().
- * This can be fixed (volunteers?) */
-		if (!S_ISREG(stb1.st_mode) || !S_ISREG(stb2.st_mode))
-			bb_error_msg_and_die("can't diff non-seekable stream");
-		print_status(diffreg(f1, f2, 0), f1, f2, NULL);
-	}
-	return status;
-}
diff --git a/coreutils/readlink.c b/coreutils/readlink.c
new file mode 100644
index 000000000..d454cbf19
--- /dev/null
+++ b/coreutils/readlink.c
@@ -0,0 +1,50 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini readlink implementation for busybox
+ *
+ * Copyright (C) 2000,2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
+ *
+ * Licensed under GPL v2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include <getopt.h>
+
+#include "libbb.h"
+
+int readlink_main(int argc, char **argv);
+int readlink_main(int argc, char **argv)
+{
+	char *buf;
+	char *fname;
+
+	USE_FEATURE_READLINK_FOLLOW(
+		unsigned opt;
+		/* We need exactly one non-option argument.  */
+		opt_complementary = "=1";
+		opt = getopt32(argc, argv, "f");
+		fname = argv[optind];
+	)
+	SKIP_FEATURE_READLINK_FOLLOW(
+		const unsigned opt = 0;
+		if (argc != 2) bb_show_usage();
+		fname = argv[1];
+	)
+
+	/* compat: coreutils readlink reports errors silently via exit code */
+	logmode = LOGMODE_NONE;
+
+	if (opt) {
+		buf = realpath(fname, bb_common_bufsiz1);
+	} else {
+		buf = xmalloc_readlink_or_warn(fname);
+	}
+
+	if (!buf)
+		return EXIT_FAILURE;
+	puts(buf);
+
+	if (ENABLE_FEATURE_CLEAN_UP && !opt)
+		free(buf);
+
+	fflush_stdout_and_exit(EXIT_SUCCESS);
+}
diff --git a/coreutils/watch.c b/coreutils/watch.c
deleted file mode 100644
index 2ad0564cd..000000000
--- a/coreutils/watch.c
+++ /dev/null
@@ -1,80 +0,0 @@
-/* vi: set sw=4 ts=4: */
-/*
- * Mini watch implementation for busybox
- *
- * Copyright (C) 2001 by Michael Habermann <mhabermann@gmx.de>
- * Copyrigjt (C) Mar 16, 2003 Manuel Novoa III   (mjn3@codepoet.org)
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
- */
-
-/* BB_AUDIT SUSv3 N/A */
-/* BB_AUDIT GNU defects -- only option -n is supported. */
-
-#include "libbb.h"
-
-// procps 2.0.18:
-// watch [-d] [-n seconds]
-//   [--differences[=cumulative]] [--interval=seconds] command
-//
-// procps-3.2.3:
-// watch [-dt] [-n seconds]
-//   [--differences[=cumulative]] [--interval=seconds] [--no-title] command
-//
-// (procps 3.x and procps 2.x are forks, not newer/older versions of the same)
-
-int watch_main(int argc, char **argv);
-int watch_main(int argc, char **argv)
-{
-	unsigned opt;
-	unsigned period = 2;
-	unsigned cmdlen = 1; // 1 for terminal NUL
-	char *header = NULL;
-	char *cmd;
-	char *tmp;
-	char **p;
-
-	opt_complementary = "-1"; // at least one param please
-	opt = getopt32(argc, argv, "+dtn:", &tmp);
-	//if (opt & 0x1) // -d (ignore)
-	//if (opt & 0x2) // -t
-	if (opt & 0x4) period = xatou(tmp);
-	argv += optind;
-
-	p = argv;
-	while (*p)
-		cmdlen += strlen(*p++) + 1;
-	tmp = cmd = xmalloc(cmdlen);
-	while (*argv) {
-		tmp += sprintf(tmp, " %s", *argv);
-		argv++;
-	}
-	cmd++; // skip initial space
-
-	while (1) {
-		printf("\033[H\033[J");
-		if (!(opt & 0x2)) { // no -t
-			int width, len;
-			char *thyme;
-			time_t t;
-
-			get_terminal_width_height(STDOUT_FILENO, &width, 0);
-			header = xrealloc(header, width--);
-			// '%-*s' pads header with spaces to the full width
-			snprintf(header, width, "Every %ds: %-*s", period, width, cmd);
-			time(&t);
-			thyme = ctime(&t);
-			len = strlen(thyme);
-			if (len < width)
-				strcpy(header + width - len, thyme);
-			puts(header);
-		}
-		fflush(stdout);
-		// TODO: 'real' watch pipes cmd's output to itself
-		// and does not allow it to overflow the screen
-		// (taking into account linewrap!)
-		system(cmd);
-		sleep(period);
-	}
-	return 0; // gcc thinks we can reach this :)
-}