Compatibility fixes:

grep: support -z
find: support --mindepth
  together +45 bytes
cpio: support -p (configurable, +230 bytes)
libbb: tweaks for cpio

TODO_config_nommu

@@ -110,6 +110,7 @@ CONFIG_BUNZIP2=y
 CONFIG_BZIP2=y
 CONFIG_CPIO=y
 CONFIG_FEATURE_CPIO_O=y
+CONFIG_FEATURE_CPIO_P=y
 CONFIG_DPKG=y
 CONFIG_DPKG_DEB=y
 CONFIG_FEATURE_DPKG_DEB_EXTRACT_ONLY=y

archival/Config.in

@@ -110,6 +110,13 @@ config FEATURE_CPIO_O
 	  This implementation of cpio can create cpio archives in the "newc"
 	  format only.
 
+config FEATURE_CPIO_P
+	bool "Support for passthrough mode"
+	default n
+	depends on FEATURE_CPIO_O
+	help
+	  Passthrough mode. Rarely used.
+
 config DPKG
 	bool "dpkg"
 	default n

archival/cpio.c

@@ -259,8 +259,9 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
 		CPIO_OPT_FILE               = (1 << 4),
 		CPIO_OPT_CREATE_LEADING_DIR = (1 << 5),
 		CPIO_OPT_PRESERVE_MTIME     = (1 << 6),
-		CPIO_OPT_CREATE             = (1 << 7),
+		CPIO_OPT_CREATE             = (1 << 7) * ENABLE_FEATURE_CPIO_O,
-		CPIO_OPT_FORMAT             = (1 << 8),
+		CPIO_OPT_FORMAT             = (1 << 8) * ENABLE_FEATURE_CPIO_O,
+		CPIO_OPT_PASSTHROUGH        = (1 << 9) * ENABLE_FEATURE_CPIO_P,
 	};
 
 #if ENABLE_GETOPT_LONG
@@ -270,21 +271,66 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_CPIO_O
 		"create\0"       No_argument       "o"
 		"format\0"       Required_argument "H"
+#if ENABLE_FEATURE_CPIO_P
+		"pass-through\0" No_argument       "p"
+#endif
 #endif
 		;
 #endif
 
-	/* Initialize */
+	/* As of now we do not enforce this: */
-	archive_handle = init_handle();
+	/* -i,-t,-o,-p are mutually exclusive */
-	archive_handle->src_fd = STDIN_FILENO;
+	/* -u,-d,-m make sense only with -i or -p */
-	archive_handle->seek = seek_by_read;
+	/* -F makes sense only with -o */
-	archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
+#if !ENABLE_FEATURE_CPIO_O
-
+	opt = getopt32(argv, "ituvF:dm", &cpio_filename);
-#if ENABLE_FEATURE_CPIO_O
+#else
-	opt = getopt32(argv, "ituvF:dmoH:", &cpio_filename, &cpio_fmt);
+	opt = getopt32(argv, "ituvF:dmoH:" USE_FEATURE_CPIO_P("p"), &cpio_filename, &cpio_fmt);
+	if (opt & CPIO_OPT_PASSTHROUGH) {
+		pid_t pid;
+		struct fd_pair pp;
 
+		if (argv[optind] == NULL)
+			bb_show_usage();
+		if (opt & CPIO_OPT_CREATE_LEADING_DIR)
+			mkdir(argv[optind], 0777);
+		/* Crude existence check:
+		 * close(xopen(argv[optind], O_RDONLY | O_DIRECTORY));
+		 * We can also xopen, fstat, IS_DIR, later fchdir.
+		 * This would check for existence earlier and cleaner.
+		 * As it stands now, if we fail xchdir later,
+		 * child dies on EPIPE, unless it caught
+		 * a diffrerent problem earlier.
+		 * This is good enough for now.
+		 */
+#if !BB_MMU
+		pp.rd = 3;
+		pp.wr = 4;
+		if (!re_execed) {
+			close(3);
+			close(4);
+			xpiped_pair(pp);
+		}
+#else
+		xpiped_pair(pp);
+#endif
+		pid = fork_or_rexec(argv);
+		if (pid == 0) { /* child */
+			close(pp.rd);
+			xmove_fd(pp.wr, STDOUT_FILENO);
+			goto dump;
+		}
+		/* parent */
+		xchdir(argv[optind++]);
+		close(pp.wr);
+		xmove_fd(pp.rd, STDIN_FILENO);
+		opt &= ~CPIO_OPT_PASSTHROUGH;
+		opt |= CPIO_OPT_EXTRACT;
+		goto skip;
+	}
+	/* -o */
 	if (opt & CPIO_OPT_CREATE) {
-		if (*cpio_fmt != 'n')
+		if (*cpio_fmt != 'n') /* we _require_ "-H newc" */
 			bb_show_usage();
 		if (opt & CPIO_OPT_FILE) {
 			fclose(stdout);
@@ -292,13 +338,18 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
 			/* Paranoia: I don't trust libc that much */
 			xdup2(fileno(stdout), STDOUT_FILENO);
 		}
+ dump:
 		return cpio_o();
 	}
-#else
+ skip:
-	opt = getopt32(argv, "ituvF:dm", &cpio_filename);
 #endif
 	argv += optind;
 
+	archive_handle = init_handle();
+	archive_handle->src_fd = STDIN_FILENO;
+	archive_handle->seek = seek_by_read;
+	archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
+
 	/* One of either extract or test options must be given */
 	if ((opt & (CPIO_OPT_TEST | CPIO_OPT_EXTRACT)) == 0) {
 		bb_show_usage();
@@ -306,9 +357,7 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
 
 	if (opt & CPIO_OPT_TEST) {
 		/* if both extract and test options are given, ignore extract option */
-		if (opt & CPIO_OPT_EXTRACT) {
 		opt &= ~CPIO_OPT_EXTRACT;
-		}
 		archive_handle->action_header = header_list;
 	}
 	if (opt & CPIO_OPT_EXTRACT) {

findutils/find.c

@@ -381,9 +381,11 @@ static int FAST_FUNC fileAction(const char *fileName,
 {
 	int i;
 #if ENABLE_FEATURE_FIND_MAXDEPTH
-	int maxdepth = (int)(ptrdiff_t)userData;
+#define minmaxdepth ((int*)userData)
 
-	if (depth > maxdepth) return SKIP;
+	if (depth < minmaxdepth[0]) return TRUE;
+	if (depth > minmaxdepth[1]) return SKIP;
+#undef minmaxdepth
 #endif
 
 #if ENABLE_FEATURE_FIND_XDEV
@@ -812,19 +814,21 @@ int find_main(int argc, char **argv)
 	static const char options[] ALIGN1 =
 	                  "-follow\0"
 USE_FEATURE_FIND_XDEV(    "-xdev\0"    )
-USE_FEATURE_FIND_MAXDEPTH("-maxdepth\0")
+USE_FEATURE_FIND_MAXDEPTH("-mindepth\0""-maxdepth\0")
 	                  ;
 	enum {
 	                  OPT_FOLLOW,
 USE_FEATURE_FIND_XDEV(    OPT_XDEV    ,)
-USE_FEATURE_FIND_MAXDEPTH(OPT_MAXDEPTH,)
+USE_FEATURE_FIND_MAXDEPTH(OPT_MINDEPTH,)
 	};
 
 	char *arg;
 	char **argp;
 	int i, firstopt, status = EXIT_SUCCESS;
 #if ENABLE_FEATURE_FIND_MAXDEPTH
-	int maxdepth = INT_MAX;
+	int minmaxdepth[2] = { 0, INT_MAX };
+#else
+#define minmaxdepth NULL
 #endif
 
 	for (firstopt = 1; firstopt < argc; firstopt++) {
@@ -875,10 +879,10 @@ USE_FEATURE_FIND_MAXDEPTH(OPT_MAXDEPTH,)
 		}
 #endif
 #if ENABLE_FEATURE_FIND_MAXDEPTH
-		if (opt == OPT_MAXDEPTH) {
+		if (opt == OPT_MINDEPTH || opt == OPT_MINDEPTH + 1) {
 			if (!argp[1])
 				bb_show_usage();
-			maxdepth = xatoi_u(argp[1]);
+			minmaxdepth[opt - OPT_MINDEPTH] = xatoi_u(argp[1]);
 			argp[0] = (char*)"-a";
 			argp[1] = (char*)"-a";
 			argp++;
@@ -895,9 +899,7 @@ USE_FEATURE_FIND_MAXDEPTH(OPT_MAXDEPTH,)
 				fileAction,     /* file action */
 				fileAction,     /* dir action */
 #if ENABLE_FEATURE_FIND_MAXDEPTH
-				/* double cast suppresses
+				minmaxdepth,    /* user data */
-				 * "cast to ptr from int of different size" */
-				(void*)(ptrdiff_t)maxdepth,/* user data */
 #else
 				NULL,           /* user data */
 #endif

findutils/grep.c

@@ -28,7 +28,9 @@
 	USE_FEATURE_GREP_CONTEXT("A:B:C:") \
 	USE_FEATURE_GREP_EGREP_ALIAS("E") \
 	USE_DESKTOP("w") \
+	USE_EXTRA_COMPAT("z") \
 	"aI"
+	
 /* ignored: -a "assume all files to be text" */
 /* ignored: -I "assume binary files have no matches" */
 
@@ -54,6 +56,7 @@ enum {
 	USE_FEATURE_GREP_CONTEXT(    OPTBIT_C ,) /* -C NUM: -A and -B combined */
 	USE_FEATURE_GREP_EGREP_ALIAS(OPTBIT_E ,) /* extended regexp */
 	USE_DESKTOP(                 OPTBIT_w ,) /* whole word match */
+	USE_EXTRA_COMPAT(            OPTBIT_z ,) /* input is NUL terminated */
 	OPT_l = 1 << OPTBIT_l,
 	OPT_n = 1 << OPTBIT_n,
 	OPT_q = 1 << OPTBIT_q,
@@ -75,6 +78,7 @@ enum {
 	OPT_C = USE_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_C)) + 0,
 	OPT_E = USE_FEATURE_GREP_EGREP_ALIAS((1 << OPTBIT_E)) + 0,
 	OPT_w = USE_DESKTOP(                 (1 << OPTBIT_w)) + 0,
+	OPT_z = USE_EXTRA_COMPAT(            (1 << OPTBIT_z)) + 0,
 };
 
 #define PRINT_FILES_WITH_MATCHES    (option_mask32 & OPT_l)
@@ -84,6 +88,7 @@ enum {
 #define PRINT_MATCH_COUNTS          (option_mask32 & OPT_c)
 #define FGREP_FLAG                  (option_mask32 & OPT_F)
 #define PRINT_FILES_WITHOUT_MATCHES (option_mask32 & OPT_L)
+#define NUL_DELIMITED               (option_mask32 & OPT_z)
 
 struct globals {
 	int max_matches;
@@ -186,7 +191,7 @@ static void print_line(const char *line, size_t line_len, int linenum, char deco
 		puts(line);
 #else
 		fwrite(line, 1, line_len, stdout);
-		putchar('\n');
+		putchar(NUL_DELIMITED ? '\0' : '\n');
 #endif
 	}
 }
@@ -197,12 +202,13 @@ static ssize_t FAST_FUNC bb_getline(char **line_ptr, size_t *line_alloc_len, FIL
 {
 	ssize_t res_sz;
 	char *line;
+	int delim = (NUL_DELIMITED ? '\0' : '\n');
 
-	res_sz = getline(line_ptr, line_alloc_len, file);
+	res_sz = getdelim(line_ptr, line_alloc_len, delim, file);
 	line = *line_ptr;
 
 	if (res_sz > 0) {
-		if (line[res_sz - 1] == '\n')
+		if (line[res_sz - 1] == delim)
 			line[--res_sz] = '\0';
 	} else {
 		free(line); /* uclibc allocates a buffer even on EOF. WTF? */
@@ -407,8 +413,11 @@ static int grep_file(FILE *file)
 #endif
 		/* Did we print all context after last requested match? */
 		if ((option_mask32 & OPT_m)
-		 && !print_n_lines_after && nmatches == max_matches)
+		 && !print_n_lines_after
+		 && nmatches == max_matches
+		) {
 			break;
+		}
 	} /* while (read line) */
 
 	/* special-case file post-processing for options where we don't print line

include/libbb.h

@@ -797,9 +797,9 @@ int run_nofork_applet_prime(struct nofork_save_area *old, int applet_no, char **
  * Both of the above will redirect fd 0,1,2 to /dev/null and drop ctty
  * (will do setsid()).
  *
- * forkexit_or_rexec(argv) = bare-bones "fork + parent exits" on MMU,
+ * fork_or_rexec(argv) = bare-bones "fork" on MMU,
  *      "vfork + re-exec ourself" on NOMMU. No fd redirection, no setsid().
- *      Currently used for setsid only. On MMU ignores argv.
+ *      On MMU ignores argv.
  *
  * Helper for network daemons in foreground mode:
  *
@@ -813,14 +813,14 @@ enum {
 	DAEMON_ONLY_SANITIZE = 8, /* internal use */
 };
 #if BB_MMU
-  void forkexit_or_rexec(void) FAST_FUNC;
+  pid_t fork_or_rexec(void) FAST_FUNC;
   enum { re_execed = 0 };
-# define forkexit_or_rexec(argv)            forkexit_or_rexec()
+# define fork_or_rexec(argv)                fork_or_rexec()
 # define bb_daemonize_or_rexec(flags, argv) bb_daemonize_or_rexec(flags)
 # define bb_daemonize(flags)                bb_daemonize_or_rexec(flags, bogus)
 #else
   void re_exec(char **argv) NORETURN FAST_FUNC;
-  void forkexit_or_rexec(char **argv) FAST_FUNC;
+  pid_t fork_or_rexec(char **argv) FAST_FUNC;
   extern bool re_execed;
   int  BUG_fork_is_unavailable_on_nommu(void) FAST_FUNC;
   int  BUG_daemon_is_unavailable_on_nommu(void) FAST_FUNC;

include/usage.h

@@ -531,24 +531,29 @@
      "\n	-l,-s	Create (sym)links" \
 
 #define cpio_trivial_usage \
-       "-[dim" USE_FEATURE_CPIO_O("o") "tuv][F cpiofile]" \
+       "-[ti" USE_FEATURE_CPIO_O("o") USE_FEATURE_CPIO_P("p") "dmvu] [-F FILE]" \
-       USE_FEATURE_CPIO_O( "[H newc]" )
+       USE_FEATURE_CPIO_O( " [-H newc]" )
 #define cpio_full_usage "\n\n" \
        "Extract or list files from a cpio archive" \
 	USE_FEATURE_CPIO_O( ", or create a cpio archive" ) \
-     "\n" \
+     "\nMain operation mode:" \
-       "Main operation mode:" \
+     "\n	-t	List" \
-     "\n	d	Make leading directories" \
+     "\n	-i	Extract" \
-     "\n	i	Extract" \
-     "\n	m	Preserve mtime" \
 	USE_FEATURE_CPIO_O( \
-     "\n	o	Create" \
+     "\n	-o	Create" \
-     "\n	H newc	Define format" \
+	) \
+	USE_FEATURE_CPIO_P( \
+     "\n	-p	Passthrough" \
+	) \
+     "\nOptions:" \
+     "\n	-d	Make leading directories" \
+     "\n	-m	Preserve mtime" \
+     "\n	-v	Verbose" \
+     "\n	-u	Overwrite" \
+     "\n	-F	Input file" \
+	USE_FEATURE_CPIO_O( \
+     "\n	-H	Define format" \
 	) \
-     "\n	t	List" \
-     "\n	v	Verbose" \
-     "\n	u	Unconditional overwrite" \
-     "\n	F	Input from file" \
 
 #define crond_trivial_usage \
        "-fbS -l N " USE_FEATURE_CROND_D("-d N ") "-L LOGFILE -c DIR"
@@ -1167,6 +1172,7 @@
 	USE_FEATURE_FIND_MAXDEPTH( \
      "\n	-maxdepth N	Descend at most N levels. -maxdepth 0 applies" \
      "\n			tests/actions to command line arguments only") \
+     "\n	-mindepth N	Do not act on first N levels" \
      "\n	-name PATTERN	File name (w/o directory name) matches PATTERN" \
      "\n	-iname PATTERN	Case insensitive -name" \
 	USE_FEATURE_FIND_PATH( \
@@ -1425,6 +1431,7 @@
        "eF" \
 	USE_FEATURE_GREP_EGREP_ALIAS("E") \
 	USE_FEATURE_GREP_CONTEXT("ABC") \
+	USE_EXTRA_COMPAT("z") \
        "] PATTERN [FILEs...]"
 #define grep_full_usage "\n\n" \
        "Search for PATTERN in each FILE or standard input\n" \
@@ -1453,6 +1460,8 @@
      "\n	-A	Print NUM lines of trailing context" \
      "\n	-B	Print NUM lines of leading context" \
      "\n	-C	Print NUM lines of output context") \
+	USE_EXTRA_COMPAT( \
+     "\n	-z	Input is NUL terminated") \
 
 #define grep_example_usage \
        "$ grep root /etc/passwd\n" \

libbb/vfork_daemon_rexec.c

@@ -251,35 +251,33 @@ void FAST_FUNC re_exec(char **argv)
 	bb_perror_msg_and_die("exec %s", bb_busybox_exec_path);
 }
 
-void FAST_FUNC forkexit_or_rexec(char **argv)
+pid_t FAST_FUNC fork_or_rexec(char **argv)
 {
 	pid_t pid;
 	/* Maybe we are already re-execed and come here again? */
 	if (re_execed)
-		return;
+		return 0; /* child */
 
 	pid = vfork();
 	if (pid < 0) /* wtf? */
 		bb_perror_msg_and_die("vfork");
 	if (pid) /* parent */
-		exit(EXIT_SUCCESS);
+		return pid;
 	/* child - re-exec ourself */
 	re_exec(argv);
 }
 #else
 /* Dance around (void)...*/
-#undef forkexit_or_rexec
+#undef fork_or_rexec
-void FAST_FUNC forkexit_or_rexec(void)
+pid_t FAST_FUNC fork_or_rexec(void)
 {
 	pid_t pid;
 	pid = fork();
 	if (pid < 0) /* wtf? */
 		bb_perror_msg_and_die("fork");
-	if (pid) /* parent */
+	return pid;
-		exit(EXIT_SUCCESS);
-	/* child */
 }
-#define forkexit_or_rexec(argv) forkexit_or_rexec()
+#define fork_or_rexec(argv) fork_or_rexec()
 #endif
 
 /* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
@@ -310,7 +308,8 @@ void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv)
 		fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
 
 	if (!(flags & DAEMON_ONLY_SANITIZE)) {
-		forkexit_or_rexec(argv);
+		if (fork_or_rexec(argv))
+			exit(EXIT_SUCCESS); /* parent */
 		/* if daemonizing, make sure we detach from stdio & ctty */
 		setsid();
 		dup2(fd, 0);

miscutils/setsid.c

@@ -26,7 +26,8 @@ int setsid_main(int argc UNUSED_PARAM, char **argv)
 	 * Otherwise our PID serves as PGID of some existing process group
 	 * and cannot be used as PGID of a new process group. */
 	if (getpgrp() == getpid())
-		forkexit_or_rexec(argv);
+		if (fork_or_rexec(argv))
+			exit(EXIT_SUCCESS); /* parent */
 
 	setsid();  /* no error possible */
 

scripts/defconfig

@@ -112,6 +112,7 @@ CONFIG_BUNZIP2=y
 CONFIG_BZIP2=y
 CONFIG_CPIO=y
 CONFIG_FEATURE_CPIO_O=y
+CONFIG_FEATURE_CPIO_P=y
 # CONFIG_DPKG is not set
 # CONFIG_DPKG_DEB is not set
 # CONFIG_FEATURE_DPKG_DEB_EXTRACT_ONLY is not set