cut: stop using static data. This alone removed ~70 bytes of code.
 + some optimizations

function                                             old     new   delta
nlists                                                 4       -      -4
cut_lists                                              4       -      -4
cut_main                                            1041     960     -81

diff --git a/coreutils/cut.c b/coreutils/cut.c
index 3bac151..0d95ff8 100644
--- a/coreutils/cut.c
+++ b/coreutils/cut.c
@@ -33,11 +33,6 @@
 	NON_RANGE = -1
 };
 
-/* growable array holding a series of lists */
-static struct cut_list *cut_lists;
-static unsigned int nlists;	/* number of elements in above list */
-
-
 static int cmpfunc(const void *a, const void *b)
 {
 	return (((struct cut_list *) a)->startpos -
@@ -45,18 +40,19 @@
 
 }
 
-static void cut_file(FILE *file, char delim)
+static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists)
 {
-	char *line = NULL;
-	unsigned int linenum = 0;	/* keep these zero-based to be consistent */
+	char *line;
+	unsigned linenum = 0;	/* keep these zero-based to be consistent */
 
 	/* go through every line in the file */
 	while ((line = xmalloc_fgetline(file)) != NULL) {
 
 		/* set up a list so we can keep track of what's been printed */
-		char * printed = xzalloc(strlen(line) * sizeof(char));
-		char * orig_line = line;
-		unsigned int cl_pos = 0;
+		int linelen = strlen(line);
+		char *printed = xzalloc(linelen * sizeof(char));
+		char *orig_line = line;
+		unsigned cl_pos = 0;
 		int spos;
 
 		/* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
@@ -64,15 +60,19 @@
 			/* print the chars specified in each cut list */
 			for (; cl_pos < nlists; cl_pos++) {
 				spos = cut_lists[cl_pos].startpos;
-				while (spos < (int)strlen(line)) {
+				while (spos < linelen) {
 					if (!printed[spos]) {
 						printed[spos] = 'X';
 						putchar(line[spos]);
 					}
 					spos++;
 					if (spos > cut_lists[cl_pos].endpos
-						|| cut_lists[cl_pos].endpos == NON_RANGE)
+					/* NON_RANGE is -1, so if below is true,
+					 * the above was true too (spos is >= 0) */
+					/* || cut_lists[cl_pos].endpos == NON_RANGE */
+					) {
 						break;
+					}
 				}
 			}
 		} else if (delim == '\n') {	/* cut by lines */
@@ -89,7 +89,8 @@
 				spos++;
 				/* go to the next list if we're at the end of this one */
 				if (spos > cut_lists[cl_pos].endpos
-					|| cut_lists[cl_pos].endpos == NON_RANGE) {
+				 || cut_lists[cl_pos].endpos == NON_RANGE
+				) {
 					cl_pos++;
 					/* get out if there's no more lists to process */
 					if (cl_pos >= nlists)
@@ -148,7 +149,7 @@
 					 * this is a list, and we're not at the end of that
 					 * list */
 				} while (spos <= cut_lists[cl_pos].endpos && line
-						 && cut_lists[cl_pos].endpos != NON_RANGE);
+						&& cut_lists[cl_pos].endpos != NON_RANGE);
 			}
 		}
 		/* if we printed anything at all, we need to finish it with a
@@ -164,17 +165,21 @@
 int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int cut_main(int argc UNUSED_PARAM, char **argv)
 {
+	/* growable array holding a series of lists */
+	struct cut_list *cut_lists = NULL;
+	unsigned nlists = 0;	/* number of elements in above list */
 	char delim = '\t';	/* delimiter, default is tab */
 	char *sopt, *ltok;
+	unsigned opt;
 
 	opt_complementary = "b--bcf:c--bcf:f--bcf";
-	getopt32(argv, optstring, &sopt, &sopt, &sopt, &ltok);
+	opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, &ltok);
 //	argc -= optind;
 	argv += optind;
-	if (!(option_mask32 & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
+	if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
 		bb_error_msg_and_die("expected a list of bytes, characters, or fields");
 
-	if (option_mask32 & CUT_OPT_DELIM_FLGS) {
+	if (opt & CUT_OPT_DELIM_FLGS) {
 		if (ltok[0] && ltok[1]) { /* more than 1 char? */
 			bb_error_msg_and_die("the delimiter must be a single character");
 		}
@@ -182,10 +187,10 @@
 	}
 
 	/*  non-field (char or byte) cutting has some special handling */
-	if (!(option_mask32 & CUT_OPT_FIELDS_FLGS)) {
+	if (!(opt & CUT_OPT_FIELDS_FLGS)) {
 		static const char _op_on_field[] ALIGN1 = " only when operating on fields";
 
-		if (option_mask32 & CUT_OPT_SUPPRESS_FLGS) {
+		if (opt & CUT_OPT_SUPPRESS_FLGS) {
 			bb_error_msg_and_die
 				("suppressing non-delimited lines makes sense%s",
 				 _op_on_field);
@@ -231,8 +236,8 @@
 				e = EOL;
 			} else {
 				e = xatoi_u(ltok);
-				/* if the user specified and end position of 0, that means "til the
-				 * end of the line */
+				/* if the user specified and end position of 0,
+				 * that means "til the end of the line" */
 				if (e == 0)
 					e = EOL;
 				e--;	/* again, arrays are zero based, lines are 1 based */
@@ -242,6 +247,8 @@
 
 			/* add the new list */
 			cut_lists = xrealloc_vector(cut_lists, 4, nlists);
+			/* NB: startpos is always >= 0,
+			 * while endpos may be = NON_RANGE (-1) */
 			cut_lists[nlists].startpos = s;
 			cut_lists[nlists].endpos = e;
 			nlists++;
@@ -269,7 +276,7 @@
 				retval = EXIT_FAILURE;
 				continue;
 			}
-			cut_file(file, delim);
+			cut_file(file, delim, cut_lists, nlists);
 			fclose_if_not_stdin(file);
 		} while (*++argv);