*: shrink by using [f]open_or_warn_stdin where appropriate

function                                             old     new   delta
lsattr_main                                           62     143     +81
open_or_warn_stdin                                     -      36     +36
fclose_if_not_stdin                                   20      47     +27
xfopen_stdin                                           -      20     +20
tac_main                                             336     356     +20
cksum_main                                           249     259     +10
bb_argv_dash                                           -       8      +8
su_main                                              448     455      +7
cmp_main                                             630     633      +3
passwd_main                                         1072    1074      +2
uudecode_main                                        317     315      -2
text_yank                                            110     108      -2
handle_incoming_and_exit                            2653    2651      -2
flags                                                  5       1      -4
write_leases                                         235     230      -5
fopen_or_warn_stdin                                   48      42      -6
fold_main                                            648     642      -6
static.argv_dash                                       8       -      -8
sum_main                                             142     128     -14
tail_main                                           1237    1221     -16
sed_main                                             711     695     -16
cmp_xfopen_input                                      17       -     -17
bb_cat                                               113      96     -17
catv_main                                            328     306     -22
strings_main                                         457     434     -23
hash_file                                            298     274     -24
sum_file                                             353     325     -28
sort_main                                            904     859     -45
expand_main                                          736     686     -50
cut_main                                            1116    1065     -51
md5_sha1_sum_main                                    549     493     -56
lsattr_args                                           90       -     -90
read_stduu                                           408     255    -153
------------------------------------------------------------------------------
(add/remove: 3/3 grow/shrink: 7/20 up/down: 214/-657)        Total: -443 bytes
   text    data     bss     dec     hex filename
 797417     658    7428  805503   c4a7f busybox_old
 796973     658    7428  805059   c48c3 busybox_unstripped

26 files changed, 214 insertions, 219 deletions

diff --git a/coreutils/cat.c b/coreutils/cat.c
index 181d96a2c..989147b39 100644
--- a/coreutils/cat.c
+++ b/coreutils/cat.c
@@ -17,18 +17,14 @@
 
 int bb_cat(char **argv)
 {
-	static const char *const argv_dash[] = { "-", NULL };
-
 	int fd;
 	int retval = EXIT_SUCCESS;
 
 	if (!*argv)
-		argv = (char**) &argv_dash;
+		argv = (char**) &bb_argv_dash;
 
 	do {
-		fd = STDIN_FILENO;
-		if (!LONE_DASH(*argv))
-			fd = open_or_warn(*argv, O_RDONLY);
+		fd = open_or_warn_stdin(*argv);
 		if (fd >= 0) {
 			/* This is not a xfunc - never exits */
 			off_t r = bb_copyfd_eof(fd, STDOUT_FILENO);
diff --git a/coreutils/catv.c b/coreutils/catv.c
index a5ee534e2..b87740ec9 100644
--- a/coreutils/catv.c
+++ b/coreutils/catv.c
@@ -27,18 +27,14 @@ int catv_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	argv += optind;
 
 	/* Read from stdin if there's nothing else to do. */
-	fd = 0;
-	if (!argv[0]) {
-		argv--;
-		goto jump_in;
-	}
+	if (!argv[0])
+		*--argv = (char*)"-";
 	do {
-		fd = open_or_warn(*argv, O_RDONLY);
+		fd = open_or_warn_stdin(*argv);
 		if (fd < 0) {
 			retval = EXIT_FAILURE;
 			continue;
 		}
- jump_in:
 		for (;;) {
 			int i, res;
 
diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index dd274afc2..6512ccc17 100644
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -9,46 +9,48 @@
 #include "libbb.h"
 
 int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int cksum_main(int argc, char **argv)
+int cksum_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	uint32_t *crc32_table = crc32_filltable(NULL, 1);
-
-	FILE *fp;
 	uint32_t crc;
 	long length, filesize;
 	int bytes_read;
-	char *cp;
+	uint8_t *cp;
 
-	int inp_stdin = (argc == optind) ? 1 : 0;
+#if ENABLE_DESKTOP
+	getopt32(argv, ""); /* coreutils 6.9 compat */
+	argv += optind;
+#else
+	argv++;
+#endif
 
 	do {
-		fp = fopen_or_warn_stdin((inp_stdin) ? bb_msg_standard_input : *++argv);
+		int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
 
+		if (fd < 0)
+			continue;
 		crc = 0;
 		length = 0;
 
 #define read_buf bb_common_bufsiz1
-		while ((bytes_read = fread(read_buf, 1, BUFSIZ, fp)) > 0) {
+		while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
 			cp = read_buf;
 			length += bytes_read;
-			while (bytes_read--)
-				crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ (*cp++)) & 0xffL];
+			do {
+				crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
+			} while (--bytes_read);
 		}
+		close(fd);
 
 		filesize = length;
 
 		for (; length; length >>= 8)
-			crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xffL];
+			crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ length) & 0xff];
 		crc ^= 0xffffffffL;
 
-		if (inp_stdin) {
-			printf("%" PRIu32 " %li\n", crc, filesize);
-			break;
-		}
-
-		printf("%" PRIu32 " %li %s\n", crc, filesize, *argv);
-		fclose(fp);
-	} while (*(argv + 1));
+		printf((*argv ? "%" PRIu32 " %li %s\n" : "%" PRIu32 " %li\n"),
+				crc, filesize, *argv);
+	} while (*argv && *++argv);
 
 	fflush_stdout_and_exit(EXIT_SUCCESS);
 }
diff --git a/coreutils/cut.c b/coreutils/cut.c
index ed6f8f608..e617ef28f 100644
--- a/coreutils/cut.c
+++ b/coreutils/cut.c
@@ -205,7 +205,7 @@ int cut_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		char *ntok;
 		int s = 0, e = 0;
 
-		/* take apart the lists, one by one (they are separated with commas */
+		/* take apart the lists, one by one (they are separated with commas) */
 		while ((ltok = strsep(&sopt, ",")) != NULL) {
 
 			/* it's actually legal to pass an empty list */
@@ -258,25 +258,18 @@ int cut_main(int argc ATTRIBUTE_UNUSED, char **argv)
 
 	{
 		int retval = EXIT_SUCCESS;
-		FILE *file = stdin;
 
-		if (!*argv) {
-			argv--;
-			goto jump_in;
-		}
+		if (!*argv)
+			*--argv = (char *)"-";
 
 		do {
-			file = stdin;
-			if (NOT_LONE_DASH(*argv))
-				file = fopen_or_warn(*argv, "r");
+			FILE *file = fopen_or_warn_stdin(*argv);
 			if (!file) {
 				retval = EXIT_FAILURE;
 				continue;
 			}
- jump_in:
 			cut_file(file, delim);
-			if (NOT_LONE_DASH(*argv))
-				fclose(file);
+			fclose_if_not_stdin(file);
 		} while (*++argv);
 
 		if (ENABLE_FEATURE_CLEAN_UP)
diff --git a/coreutils/expand.c b/coreutils/expand.c
index c0133956f..a7ac8ea84 100644
--- a/coreutils/expand.c
+++ b/coreutils/expand.c
@@ -154,7 +154,7 @@ int expand_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
 		USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
 		opt = getopt32(argv, "it:", &opt_t);
-	} else if (ENABLE_UNEXPAND) {
+	} else {
 		USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
 		/* -t NUM sets also -a */
 		opt_complementary = "ta";
@@ -166,32 +166,23 @@ int expand_main(int argc ATTRIBUTE_UNUSED, char **argv)
 
 	argv += optind;
 
-	/* If no args are given, read from stdin */
 	if (!*argv) {
 		*--argv = (char*)bb_msg_standard_input;
-		goto use_stdin;
 	}
-
 	do {
-		if (NOT_LONE_CHAR(*argv, '-')) {
-			file = fopen_or_warn(*argv, "r");
-			if (!file) {
-				exit_status = EXIT_FAILURE;
-				continue;
-			}
-		} else {
- use_stdin:
-			file = stdin;
+		file = fopen_or_warn_stdin(*argv);
+		if (!file) {
+			exit_status = EXIT_FAILURE;
+			continue;
 		}
 
 		if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
 			USE_EXPAND(expand(file, tab_size, opt));
-		else if (ENABLE_UNEXPAND)
+		else
 			USE_UNEXPAND(unexpand(file, tab_size, opt));
 
 		/* Check and close the file */
-		/* We do want all of them to execute, thus | instead of || */
-		if (ferror(file) | fclose_if_not_stdin(file)) {
+		if (fclose_if_not_stdin(file)) {
 			bb_simple_perror_msg(*argv);
 			exit_status = EXIT_FAILURE;
 		}
diff --git a/coreutils/fold.c b/coreutils/fold.c
index ed484edf0..e2a30d5d4 100644
--- a/coreutils/fold.c
+++ b/coreutils/fold.c
@@ -12,18 +12,17 @@
 
 #include "libbb.h"
 
-static unsigned long flags;
-#define FLAG_COUNT_BYTES	1
-#define FLAG_BREAK_SPACES	2
-#define FLAG_WIDTH			4
+/* Must match getopt32 call */
+#define FLAG_COUNT_BYTES        1
+#define FLAG_BREAK_SPACES       2
+#define FLAG_WIDTH              4
 
 /* Assuming the current column is COLUMN, return the column that
    printing C will move the cursor to.
    The first column is 0. */
-
 static int adjust_column(int column, char c)
 {
-	if (!(flags & FLAG_COUNT_BYTES)) {
+	if (!(option_mask32 & FLAG_COUNT_BYTES)) {
 		if (c == '\b') {
 			if (column > 0)
 				column--;
@@ -54,29 +53,27 @@ int fold_main(int argc, char **argv)
 			char const *a = argv[i];
 
 			if (*a++ == '-') {
-				if (*a == '-' && !a[1])
+				if (*a == '-' && !a[1]) /* "--" */
 					break;
-				if (isdigit(*a)) {
+				if (isdigit(*a))
 					argv[i] = xasprintf("-w%s", a);
-				}
 			}
 		}
 	}
 
-	flags = getopt32(argv, "bsw:", &w_opt);
-	if (flags & FLAG_WIDTH)
+	getopt32(argv, "bsw:", &w_opt);
+	if (option_mask32 & FLAG_WIDTH)
 		width = xatoul_range(w_opt, 1, 10000);
 
 	argv += optind;
-	if (!*argv) {
+	if (!*argv)
 		*--argv = (char*)"-";
-	}
 
 	do {
 		FILE *istream = fopen_or_warn_stdin(*argv);
 		int c;
 		int column = 0;		/* Screen column where next char will go. */
-		int offset_out = 0;	/* Index in `line_out' for next char. */
+		int offset_out = 0;	/* Index in 'line_out' for next char. */
 
 		if (istream == NULL) {
 			errs |= EXIT_FAILURE;
@@ -102,7 +99,7 @@ int fold_main(int argc, char **argv)
 				/* This character would make the line too long.
 				   Print the line plus a newline, and make this character
 				   start the next line. */
-				if (flags & FLAG_BREAK_SPACES) {
+				if (option_mask32 & FLAG_BREAK_SPACES) {
 					/* Look for the last blank. */
 					int logical_end;
 
@@ -144,7 +141,7 @@ int fold_main(int argc, char **argv)
 			fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
 		}
 
-		if (ferror(istream) || fclose_if_not_stdin(istream)) {
+		if (fclose_if_not_stdin(istream)) {
 			bb_simple_perror_msg(*argv);	/* Avoid multibyte problems. */
 			errs |= EXIT_FAILURE;
 		}
diff --git a/coreutils/head.c b/coreutils/head.c
index 629307719..570f140b1 100644
--- a/coreutils/head.c
+++ b/coreutils/head.c
@@ -91,19 +91,19 @@ int head_main(int argc, char **argv)
 		}
 	}
 
+	argc -= optind;
 	argv += optind;
-	if (!*argv) {
+	if (!*argv)
 		*--argv = (char*)"-";
-	}
 
 	fmt = header_fmt_str + 1;
 #if ENABLE_FEATURE_FANCY_HEAD
-	if (argc - optind <= header_threshhold) {
+	if (argc <= header_threshhold) {
 		header_threshhold = 0;
 	}
 #else
-	if (argc <= optind + 1) {
-		fmt += 11;
+	if (argc <= 1) {
+		fmt += 11; /* "" */
 	}
 	/* Now define some things here to avoid #ifdefs in the code below.
 	 * These should optimize out of the if conditions below. */
diff --git a/coreutils/md5_sha1_sum.c b/coreutils/md5_sha1_sum.c
index e94f2ceb1..080eac5f4 100644
--- a/coreutils/md5_sha1_sum.c
+++ b/coreutils/md5_sha1_sum.c
@@ -36,12 +36,9 @@ static uint8_t *hash_file(const char *filename, hash_algo_t hash_algo)
 	void (*update)(const void*, size_t, void*);
 	void (*final)(void*, void*);
 
-	src_fd = STDIN_FILENO;
-	if (NOT_LONE_DASH(filename)) {
-		src_fd = open_or_warn(filename, O_RDONLY);
-		if (src_fd < 0) {
-			return NULL;
-		}
+	src_fd = open_or_warn_stdin(filename);
+	if (src_fd < 0) {
+		return NULL;
 	}
 
 	/* figure specific hash algorithims */
@@ -78,7 +75,7 @@ static uint8_t *hash_file(const char *filename, hash_algo_t hash_algo)
 }
 
 int md5_sha1_sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int md5_sha1_sum_main(int argc, char **argv)
+int md5_sha1_sum_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	int return_value = EXIT_SUCCESS;
 	uint8_t *hash_value;
@@ -90,6 +87,10 @@ int md5_sha1_sum_main(int argc, char **argv)
 	if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK)
 		flags = getopt32(argv, "scw");
 	else optind = 1;
+	argv += optind;
+	//argc -= optind;
+	if (!*argv)
+		*--argv = (char*)"-";
 
 	if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && !(flags & FLAG_CHECK)) {
 		if (flags & FLAG_SILENT) {
@@ -101,26 +102,18 @@ int md5_sha1_sum_main(int argc, char **argv)
 		}
 	}
 
-	if (argc == optind) {
-		argv[argc++] = (char*)"-";
-	}
-
 	if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && (flags & FLAG_CHECK)) {
 		FILE *pre_computed_stream;
 		int count_total = 0;
 		int count_failed = 0;
-		char *file_ptr = argv[optind];
 		char *line;
 
-		if (optind + 1 != argc) {
+		if (argv[1]) {
 			bb_error_msg_and_die
 				("only one argument may be specified when using -c");
 		}
 
-		pre_computed_stream = stdin;
-		if (NOT_LONE_DASH(file_ptr)) {
-			pre_computed_stream = xfopen(file_ptr, "r");
-		}
+		pre_computed_stream = xfopen_stdin(argv[0]);
 
 		while ((line = xmalloc_getline(pre_computed_stream)) != NULL) {
 			char *filename_ptr;
@@ -168,17 +161,15 @@ int md5_sha1_sum_main(int argc, char **argv)
 		}
 		*/
 	} else {
-		while (optind < argc) {
-			char *file_ptr = argv[optind++];
-
-			hash_value = hash_file(file_ptr, hash_algo);
+		do {
+			hash_value = hash_file(*argv, hash_algo);
 			if (hash_value == NULL) {
 				return_value = EXIT_FAILURE;
 			} else {
-				printf("%s  %s\n", hash_value, file_ptr);
+				printf("%s  %s\n", hash_value, *argv);
 				free(hash_value);
 			}
-		}
+		} while (*++argv);
 	}
 	return return_value;
 }
diff --git a/coreutils/sort.c b/coreutils/sort.c
index 510f7a235..15566ce2b 100644
--- a/coreutils/sort.c
+++ b/coreutils/sort.c
@@ -351,10 +351,13 @@ int sort_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	if (option_mask32 & FLAG_b) option_mask32 |= FLAG_bb;
 
 	/* Open input files and read data */
-	for (i = argv[optind] ? optind : optind-1; argv[i]; i++) {
-		fp = stdin;
-		if (i >= optind && NOT_LONE_DASH(argv[i]))
-			fp = xfopen(argv[i], "r");
+	argv += optind;
+	if (!*argv)
+		*--argv = (char*)"-";
+	do {
+		/* coreutils 6.9 compat: abort on first open error,
+		 * do not continue to next file: */
+		fp = xfopen_stdin(*argv);
 		for (;;) {
 			line = GET_LINE(fp);
 			if (!line) break;
@@ -362,8 +365,9 @@ int sort_main(int argc ATTRIBUTE_UNUSED, char **argv)
 				lines = xrealloc(lines, sizeof(char *) * (linecount + 64));
 			lines[linecount++] = line;
 		}
-		fclose(fp);
-	}
+		fclose_if_not_stdin(fp);
+	} while (*++argv);
+
 #if ENABLE_FEATURE_SORT_BIG
 	/* if no key, perform alphabetic sort */
 	if (!key_list)
diff --git a/coreutils/sum.c b/coreutils/sum.c
index 65478b0a1..e6cfbfd80 100644
--- a/coreutils/sum.c
+++ b/coreutils/sum.c
@@ -21,20 +21,17 @@ enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
    The checksum varies depending on sizeof (int). */
 /* SYSV: calculate and print the checksum and the size in 512-byte blocks */
 /* Return 1 if successful.  */
-static unsigned sum_file(const char *file, const unsigned type)
+static unsigned sum_file(const char *file, unsigned type)
 {
 #define buf bb_common_bufsiz1
 	unsigned long long total_bytes = 0;
-	int fd = 0, r;
-
+	int fd, r;
 	/* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
 	unsigned s = 0;
 
-	if (NOT_LONE_DASH(file)) {
-		fd = open(file, O_RDONLY);
-		if (fd == -1)
-			goto ret_bad;
-	}
+	fd = open_or_warn_stdin(file);
+	if (fd == -1)
+		return 0;
 
 	while (1) {
 		size_t bytes_read = safe_read(fd, buf, BUFSIZ);
@@ -44,7 +41,6 @@ static unsigned sum_file(const char *file, const unsigned type)
 			if (!bytes_read && !r)
 				/* no error */
 				break;
- ret_bad:
 			bb_perror_msg(file);
 			return 0;
 		}
@@ -75,26 +71,29 @@ static unsigned sum_file(const char *file, const unsigned type)
 }
 
 int sum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int sum_main(int argc, char **argv)
+int sum_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	unsigned n;
 	unsigned type = SUM_BSD;
 
 	n = getopt32(argv, "sr");
+	argv += optind;
 	if (n & 1) type = SUM_SYSV;
 	/* give the bsd priority over sysv func */
 	if (n & 2) type = SUM_BSD;
 
-	if (argc == optind) {
+	if (!argv[0]) {
 		/* Do not print the name */
 		n = sum_file("-", type);
 	} else {
 		/* Need to print the name if either
 		   - more than one file given
 		   - doing sysv */
-		type += argc - 1 > optind || type == SUM_SYSV;
-		for (n = 1; optind < argc; optind++)
-			n &= sum_file(argv[optind], type);
+		type += (argv[1] || type == SUM_SYSV);
+		n = 1;
+		do {
+			n &= sum_file(*argv, type);
+		} while (*++argv);
 	}
 	return !n;
 }
diff --git a/coreutils/tac.c b/coreutils/tac.c
index ddadcc7bc..af70f3092 100644
--- a/coreutils/tac.c
+++ b/coreutils/tac.c
@@ -22,7 +22,7 @@
 
 struct lstring {
 	int size;
-	char buf[];
+	char buf[1];
 };
 
 int tac_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -34,7 +34,21 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	llist_t *list = NULL;
 	int retval = EXIT_SUCCESS;
 
+#if ENABLE_DESKTOP
+/* tac from coreutils 6.9 supports:
+       -b, --before
+              attach the separator before instead of after
+       -r, --regex
+              interpret the separator as a regular expression
+       -s, --separator=STRING
+              use STRING as the separator instead of newline
+We support none, but at least we will complain or handle "--":
+*/
+	getopt32(argv, "");
+	argv += optind;
+#else
 	argv++;
+#endif
 	if (!*argv)
 		*--argv = (char *)"-";
 	/* We will read from last file to first */
@@ -48,6 +62,7 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		name--;
 		f = fopen_or_warn_stdin(*name);
 		if (f == NULL) {
+			/* error message is printed by fopen_or_warn_stdin */
 			retval = EXIT_FAILURE;
 			continue;
 		}
@@ -61,7 +76,7 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
 					line = xrealloc(line, i + 0x7f + sizeof(int) + 1);
 				line->buf[i++] = ch;
 			}
-			if ((ch == '\n' || ch == EOF) && i) {
+			if (ch == '\n' || (ch == EOF && i != 0)) {
 				line = xrealloc(line, i + sizeof(int));
 				line->size = i;
 				llist_add_to(&list, line);
@@ -69,9 +84,8 @@ int tac_main(int argc ATTRIBUTE_UNUSED, char **argv)
 				i = 0;
 			}
 		} while (ch != EOF);
-		/* fgetc sets errno to ENOENT on EOF, but     */
-		/* fopen_or_warn_stdin would catch this error */
-		/* so we can filter it out here.              */
+		/* fgetc sets errno to ENOENT on EOF, we don't want
+		 * to warn on this non-error! */
 		if (errno && errno != ENOENT) {
 			bb_simple_perror_msg(*name);
 			retval = EXIT_FAILURE;
diff --git a/coreutils/tail.c b/coreutils/tail.c
index 340697f88..52aa8f69e 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -101,16 +101,12 @@ int tail_main(int argc, char **argv)
 
 #if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
 	/* Allow legacy syntax of an initial numeric option without -n. */
-	if (argc >= 2 && (argv[1][0] == '+' || argv[1][0] == '-')
+	if (argv[1] && (argv[1][0] == '+' || argv[1][0] == '-')
 	 && isdigit(argv[1][1])
 	) {
-		/* replacing arg[0] with "-n" can segfault, so... */
-		argv[1] = xasprintf("-n%s", argv[1]);
-#if 0 /* If we ever decide to make tail NOFORK */
-		char *s = alloca(strlen(argv[1]) + 3);
-		sprintf(s, "-n%s", argv[1]);
-		argv[1] = s;
-#endif
+		count = eat_num(&argv[1][1]);
+		argv++;
+		argc--;
 	}
 #endif
 
@@ -133,8 +129,7 @@ int tail_main(int argc, char **argv)
 
 	/* open all the files */
 	fds = xmalloc(sizeof(int) * (argc + 1));
-	nfiles = i = 0;
-	if (argc == 0) {
+	if (!argv[0]) {
 		struct stat statbuf;
 
 		if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
@@ -142,13 +137,14 @@ int tail_main(int argc, char **argv)
 		}
 		*argv = (char *) bb_msg_standard_input;
 	}
+	nfiles = i = 0;
 	do {
-		FILE* fil = fopen_or_warn_stdin(argv[i]);
-		if (!fil) {
+		int fd = open_or_warn_stdin(argv[i]);
+		if (fd < 0) {
 			G.status = EXIT_FAILURE;
 			continue;
 		}
-		fds[nfiles] = fileno(fil);
+		fds[nfiles] = fd;
 		argv[nfiles++] = argv[i];
 	} while (++i < argc);
 
diff --git a/coreutils/uudecode.c b/coreutils/uudecode.c
index 34a22398c..4c619dec5 100644
--- a/coreutils/uudecode.c
+++ b/coreutils/uudecode.c
@@ -19,48 +19,57 @@ static void read_stduu(FILE *src_stream, FILE *dst_stream)
 	char *line;
 
 	while ((line = xmalloc_getline(src_stream)) != NULL) {
-		int length;
-		char *line_ptr = line;
+		int encoded_len, str_len;
+		char *line_ptr, *dst;
 
 		if (strcmp(line, "end") == 0) {
-			return;
+			return; /* the only non-error exit */
 		}
-		length = ((*line_ptr - 0x20) & 0x3f)* 4 / 3;
 
-		if (length <= 0) {
+		line_ptr = line;
+		while (*line_ptr) {
+			*line_ptr = (*line_ptr - 0x20) & 0x3f;
+			line_ptr++;
+		}
+		str_len = line_ptr - line;
+
+		encoded_len = line[0] * 4 / 3;
+		/* Check that line is not too short. (we tolerate
+		 * overly _long_ line to accomodate possible extra '`').
+		 * Empty line case is also caught here. */
+		if (str_len <= encoded_len) {
+			break; /* go to bb_error_msg_and_die("short file"); */
+		}
+		if (encoded_len <= 0) {
 			/* Ignore the "`\n" line, why is it even in the encode file ? */
+			free(line);
 			continue;
 		}
-		if (length > 60) {
+		if (encoded_len > 60) {
 			bb_error_msg_and_die("line too long");
 		}
 
-		line_ptr++;
-		/* Tolerate an overly long line to accomodate a possible exta '`' */
-		if (strlen(line_ptr) < (size_t)length) {
-			bb_error_msg_and_die("short file");
-		}
-
-		while (length > 0) {
+		dst = line;
+		line_ptr = line + 1;
+		do {
 			/* Merge four 6 bit chars to three 8 bit chars */
-			fputc(((line_ptr[0] - 0x20) & 077) << 2 | ((line_ptr[1] - 0x20) & 077) >> 4, dst_stream);
-			line_ptr++;
-			length--;
-			if (length == 0) {
+			*dst++ = line_ptr[0] << 2 | line_ptr[1] >> 4;
+			encoded_len--;
+			if (encoded_len == 0) {
 				break;
 			}
 
-			fputc(((line_ptr[0] - 0x20) & 077) << 4 | ((line_ptr[1] - 0x20) & 077) >> 2, dst_stream);
-			line_ptr++;
-			length--;
-			if (length == 0) {
+			*dst++ = line_ptr[1] << 4 | line_ptr[2] >> 2;
+			encoded_len--;
+			if (encoded_len == 0) {
 				break;
 			}
 
-			fputc(((line_ptr[0] - 0x20) & 077) << 6 | ((line_ptr[1] - 0x20) & 077), dst_stream);
-			line_ptr += 2;
-			length -= 2;
-		}
+			*dst++ = line_ptr[2] << 6 | line_ptr[3];
+			line_ptr += 4;
+			encoded_len -= 2;
+		} while (encoded_len > 0);
+		fwrite(line, 1, dst - line, dst_stream);
 		free(line);
 	}
 	bb_error_msg_and_die("short file");
@@ -129,7 +138,7 @@ static void read_base64(FILE *src_stream, FILE *dst_stream)
 int uudecode_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int uudecode_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
-	FILE *src_stream = stdin;
+	FILE *src_stream;
 	char *outname = NULL;
 	char *line;
 
@@ -137,8 +146,9 @@ int uudecode_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	getopt32(argv, "o:", &outname);
 	argv += optind;
 
-	if (argv[0])
-		src_stream = xfopen(argv[0], "r");
+	if (!*argv)
+		*--argv = (char*)"-";
+	src_stream = xfopen_stdin(*argv);
 
 	/* Search for the start of the encoding */
 	while ((line = xmalloc_getline(src_stream)) != NULL) {
@@ -159,7 +169,7 @@ int uudecode_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		}
 
 		/* begin line found. decode and exit */
-		mode = strtoul(line_ptr, NULL, 8);
+		mode = bb_strtou(line_ptr, NULL, 8);
 		if (outname == NULL) {
 			outname = strchr(line_ptr, ' ');
 			if ((outname == NULL) || (*outname == '\0')) {
@@ -170,7 +180,7 @@ int uudecode_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		dst_stream = stdout;
 		if (NOT_LONE_DASH(outname)) {
 			dst_stream = xfopen(outname, "w");
-			chmod(outname, mode & (S_IRWXU | S_IRWXG | S_IRWXO));
+			fchmod(fileno(dst_stream), mode & (S_IRWXU | S_IRWXG | S_IRWXO));
 		}
 		free(line);
 		decode_fn_ptr(src_stream, dst_stream);
diff --git a/coreutils/yes.c b/coreutils/yes.c
index 269d2a0c2..9d3f67550 100644
--- a/coreutils/yes.c
+++ b/coreutils/yes.c
@@ -21,22 +21,21 @@
 int yes_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int yes_main(int argc, char **argv)
 {
-	char **first_arg;
+	char **pp;
 
 	argv[0] = (char*)"y";
 	if (argc != 1) {
 		++argv;
 	}
 
-	first_arg = argv;
 	do {
+		pp = argv;
 		while (1) {
-			fputs(*argv, stdout);
-			if (!*++argv)
+			fputs(*pp, stdout);
+			if (!*++pp)
 				break;
 			putchar(' ');
 		}
-		argv = first_arg;
 	} while (putchar('\n') != EOF);
 
 	bb_perror_nomsg_and_die();
diff --git a/e2fsprogs/lsattr.c b/e2fsprogs/lsattr.c
index c58948698..13eeb35f5 100644
--- a/e2fsprogs/lsattr.c
+++ b/e2fsprogs/lsattr.c
@@ -102,10 +102,8 @@ int lsattr_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	argv += optind;
 
 	if (!*argv)
-		lsattr_args(".");
-	else {
-		do lsattr_args(*argv++); while (*argv);
-	}
+		*--argv = (char*)".";
+	do lsattr_args(*argv++); while (*argv);
 
 	return EXIT_SUCCESS;
 }
diff --git a/editors/cmp.c b/editors/cmp.c
index 9189b3150..b211adf9f 100644
--- a/editors/cmp.c
+++ b/editors/cmp.c
@@ -23,16 +23,6 @@
 
 #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[] ALIGN1 = "cmp: EOF on %s\n";
 static const char fmt_differ[] ALIGN1 = "%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"
@@ -65,7 +55,7 @@ int cmp_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	argv += optind;
 
 	filename1 = *argv;
-	fp1 = cmp_xfopen_input(filename1);
+	fp1 = xfopen_stdin(filename1);
 
 	if (*++argv) {
 		filename2 = *argv;
@@ -79,7 +69,7 @@ int cmp_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #endif
 	}
 
-	fp2 = cmp_xfopen_input(filename2);
+	fp2 = xfopen_stdin(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
diff --git a/editors/sed.c b/editors/sed.c
index a0994aec0..32911f8f9 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -1231,7 +1231,7 @@ static void add_cmd_block(char *cmdstr)
 }
 
 int sed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int sed_main(int argc, char **argv)
+int sed_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	enum {
 		OPT_in_place = 1 << 0,
@@ -1246,7 +1246,7 @@ int sed_main(int argc, char **argv)
 	if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff);
 
 	/* Lie to autoconf when it starts asking stupid questions. */
-	if (argc == 2 && !strcmp(argv[1], "--version")) {
+	if (argv[1] && !strcmp(argv[1], "--version")) {
 		puts("This is not GNU sed version 4.0");
 		return 0;
 	}
@@ -1257,7 +1257,7 @@ int sed_main(int argc, char **argv)
 	                    "nn"; /* count -n */
 	opt = getopt32(argv, "irne:f:", &opt_e, &opt_f,
 			    &G.be_quiet); /* counter for -n */
-	argc -= optind;
+	//argc -= optind;
 	argv += optind;
 	if (opt & OPT_in_place) { // -i
 		atexit(cleanup_outname);
@@ -1283,10 +1283,9 @@ int sed_main(int argc, char **argv)
 	}
 	/* if we didn't get a pattern from -e or -f, use argv[0] */
 	if (!(opt & 0x18)) {
-		if (!argc)
+		if (!*argv)
 			bb_show_usage();
 		add_cmd_block(*argv++);
-		argc--;
 	}
 	/* Flush any unfinished commands. */
 	add_cmd("");
@@ -1306,7 +1305,7 @@ int sed_main(int argc, char **argv)
 		int i;
 		FILE *file;
 
-		for (i = 0; i < argc; i++) {
+		for (i = 0; argv[i]; i++) {
 			struct stat statbuf;
 			int nonstdoutfd;
 
diff --git a/include/libbb.h b/include/libbb.h
index c6c2be244..99d681dbe 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -333,6 +333,7 @@ int xopen(const char *pathname, int flags);
 int xopen3(const char *pathname, int flags, int mode);
 int open_or_warn(const char *pathname, int flags);
 int open3_or_warn(const char *pathname, int flags, int mode);
+int open_or_warn_stdin(const char *pathname);
 void xrename(const char *oldpath, const char *newpath);
 int rename_or_warn(const char *oldpath, const char *newpath);
 off_t xlseek(int fd, off_t offset, int whence);
@@ -559,6 +560,7 @@ extern FILE *xfopen(const char *filename, const char *mode);
 /* Prints warning to stderr and returns NULL on failure: */
 extern FILE *fopen_or_warn(const char *filename, const char *mode);
 /* "Opens" stdin if filename is special, else just opens file: */
+extern FILE *xfopen_stdin(const char *filename);
 extern FILE *fopen_or_warn_stdin(const char *filename);
 
 int bb_pstrcmp(const void *a, const void *b);
@@ -741,6 +743,7 @@ void bb_sanitize_stdio(void);
 int sanitize_env_if_suid(void);
 
 
+extern const char *const bb_argv_dash[]; /* "-", NULL */
 extern const char *opt_complementary;
 #if ENABLE_GETOPT_LONG
 #define No_argument "\0"
diff --git a/libbb/fclose_nonstdin.c b/libbb/fclose_nonstdin.c
index 88e8474f2..768ee946d 100644
--- a/libbb/fclose_nonstdin.c
+++ b/libbb/fclose_nonstdin.c
@@ -16,8 +16,10 @@
 
 int fclose_if_not_stdin(FILE *f)
 {
-	if (f != stdin) {
-		return fclose(f);
-	}
-	return 0;
+	/* Some more paranoid applets want ferror() check too */
+	int r = ferror(f); /* NB: does NOT set errno! */
+	if (r) errno = EIO; /* so we'll help it */
+	if (f != stdin)
+		return (r | fclose(f)); /* fclose does set errno on error */
+	return r;
 }
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index f48ccaa6a..9e53dfd08 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -281,6 +281,8 @@ Special characters:
 
 /* Code here assumes that 'unsigned' is at least 32 bits wide */
 
+const char *const bb_argv_dash[] = { "-", NULL };
+
 const char *opt_complementary;
 
 enum {
diff --git a/libbb/wfopen_input.c b/libbb/wfopen_input.c
index 1b4928e1f..a7c1c32f5 100644
--- a/libbb/wfopen_input.c
+++ b/libbb/wfopen_input.c
@@ -10,8 +10,6 @@
 /* A number of applets need to open a file for reading, where the filename
  * is a command line arg.  Since often that arg is '-' (meaning stdin),
  * we avoid testing everywhere by consolidating things in this routine.
- *
- * Note: we also consider "" to mean stdin (for 'cmp' at least).
  */
 
 #include "libbb.h"
@@ -21,11 +19,30 @@ FILE *fopen_or_warn_stdin(const char *filename)
 	FILE *fp = stdin;
 
 	if (filename != bb_msg_standard_input
-	 && filename[0]
 	 && NOT_LONE_DASH(filename)
 	) {
 		fp = fopen_or_warn(filename, "r");
 	}
-
 	return fp;
 }
+
+FILE *xfopen_stdin(const char *filename)
+{
+	FILE *fp = fopen_or_warn_stdin(filename);
+	if (fp)
+		return fp;
+	xfunc_die();	/* We already output an error message. */
+}
+
+int open_or_warn_stdin(const char *filename)
+{
+	int fd = STDIN_FILENO;
+
+	if (filename != bb_msg_standard_input
+	 && NOT_LONE_DASH(filename)
+	) {
+		fd = open_or_warn(filename, O_RDONLY);
+	}
+
+	return fd;
+}
diff --git a/loginutils/su.c b/loginutils/su.c
index afb9843f8..1a35f0e4f 100644
--- a/loginutils/su.c
+++ b/loginutils/su.c
@@ -12,7 +12,7 @@
 #define SU_OPT_l (4)
 
 int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int su_main(int argc, char **argv)
+int su_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
 	unsigned flags;
 	char *opt_shell = NULL;
@@ -24,19 +24,17 @@ int su_main(int argc, char **argv)
 	char *old_user;
 
 	flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
-	argc -= optind;
+	//argc -= optind;
 	argv += optind;
 
-	if (argc && LONE_DASH(argv[0])) {
+	if (argv[0] && LONE_DASH(argv[0])) {
 		flags |= SU_OPT_l;
-		argc--;
 		argv++;
 	}
 
 	/* get user if specified */
-	if (argc) {
+	if (argv[0]) {
 		opt_username = argv[0];
-		//argc--; - not used below anyway
 		argv++;
 	}
 
diff --git a/miscutils/strings.c b/miscutils/strings.c
index 57a2c0a17..5efbabf6f 100644
--- a/miscutils/strings.c
+++ b/miscutils/strings.c
@@ -23,7 +23,7 @@ int strings_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	unsigned opt;
 	unsigned count;
 	off_t offset;
-	FILE *file = stdin;
+	FILE *file;
 	char *string;
 	const char *fmt = "%s: ";
 	const char *n_arg = "4";
@@ -40,16 +40,14 @@ int strings_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	if (!*argv) {
 		fmt = "{%s}: ";
 		*--argv = (char *)bb_msg_standard_input;
-		goto PIPE;
 	}
 
 	do {
-		file = fopen_or_warn(*argv, "r");
+		file = fopen_or_warn_stdin(*argv);
 		if (!file) {
 			status = EXIT_FAILURE;
 			continue;
 		}
- PIPE:
 		offset = 0;
 		count = 0;
 		do {
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 5bf1a491c..ca0c6cb20 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -377,7 +377,7 @@ void write_leases(void)
 	time_t curr = time(0);
 	unsigned long tmp_time;
 
-	fp = open3_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC, 0666);
+	fp = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
 	if (fp < 0) {
 		return;
 	}
diff --git a/shell/lash_unused.c b/shell/lash_unused.c
index 10a9120e2..d57f584b2 100644
--- a/shell/lash_unused.c
+++ b/shell/lash_unused.c
@@ -566,7 +566,7 @@ static int setup_redirects(struct child_prog *prog, int squirrel[])
 			break;
 		}
 
-		openfd = open3_or_warn(redir->filename, mode, 0666);
+		openfd = open_or_warn(redir->filename, mode);
 		if (openfd < 0) {
 			/* this could get lost if stderr has been redirected, but
 			   bash and ash both lose it as well (though zsh doesn't!) */
diff --git a/util-linux/hexdump.c b/util-linux/hexdump.c
index 670867054..cdb17ca3b 100644
--- a/util-linux/hexdump.c
+++ b/util-linux/hexdump.c
@@ -73,7 +73,7 @@ int hexdump_main(int argc, char **argv)
 	}
 
 	/* We cannot use getopt32: in hexdump options are cumulative.
-	 * E.g. hexdump -C -C file should dump each line twice */
+	 * E.g. "hexdump -C -C file" should dump each line twice */
 	while ((ch = getopt(argc, argv, hexdump_opts)) > 0) {
 		p = strchr(hexdump_opts, ch);
 		if (!p)