ed: large cleanup

function                                             old     new   delta
bad_nums                                               -      43     +43
skip_blank                                             -      24     +24
getNum                                               557     578     +21
insertLine                                           159     163      +4
setCurNum                                             31      33      +2
lastNum                                                4       -      -4
fileName                                               4       -      -4
dirty                                                  4       -      -4
curNum                                                 4       -      -4
curLine                                                4       -      -4
bufUsed                                                4       -      -4
bufSize                                                4       -      -4
bufPtr                                                 4       -      -4
bufBase                                                4       -      -4
printLines                                           357     345     -12
findLine                                             165     152     -13
lines                                                 16       -     -16
deleteLines                                          203     144     -59
readLines                                            538     473     -65
addLines                                             163      87     -76
marks                                                104       -    -104
termEdit                                             140       -    -140
ed_main                                             3125    2654    -471
------------------------------------------------------------------------------
(add/remove: 2/12 grow/shrink: 3/6 up/down: 94/-992)         Total: -898 bytes
   text    data     bss     dec     hex filename
 771142    1034   10564  782740   bf194 busybox_old
 770265    1034   10404  781703   bed87 busybox_unstripped

# size */ed.o
   text    data     bss     dec     hex filename
   6370       0     156    6526    197e editors.org/ed.o
   5505       0       0    5505    1581 editors/ed.o

1 files changed, 135 insertions, 305 deletions

diff --git a/editors/ed.c b/editors/ed.c
index e6576b4..f5b9c39 100644
--- a/editors/ed.c
+++ b/editors/ed.c
@@ -9,6 +9,14 @@
 
 #include "libbb.h"
 
+typedef struct LINE {
+	struct LINE *next;
+	struct LINE *prev;
+	int len;
+	char data[1];
+} LINE;
+
+
 #define searchString bb_common_bufsiz1
 
 enum {
@@ -17,64 +25,92 @@ enum {
 	INITBUF_SIZE = 1024, /* initial buffer size */
 };
 
-typedef struct LINE {
-	struct LINE *next;
-	struct LINE *prev;
-	int len;
-	char data[1];
-} LINE;
+struct globals {
+	int curNum;
+	int lastNum;
+	int bufUsed;
+	int bufSize;
+	LINE *curLine;
+	char *bufBase;
+	char *bufPtr;
+	char *fileName;
+	LINE lines;
+	smallint dirty;
+	int marks[26];
+};
+#define G (*ptr_to_globals)
+#define curLine            (G.curLine           )
+#define bufBase            (G.bufBase           )
+#define bufPtr             (G.bufPtr            )
+#define fileName           (G.fileName          )
+#define curNum             (G.curNum            )
+#define lastNum            (G.lastNum           )
+#define bufUsed            (G.bufUsed           )
+#define bufSize            (G.bufSize           )
+#define dirty              (G.dirty             )
+#define lines              (G.lines             )
+#define marks              (G.marks             )
+#define INIT_G() do { \
+	PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+} while (0)
 
-static LINE lines, *curLine;
-static int curNum, lastNum, marks[26], dirty;
-static char *bufBase, *bufPtr, *fileName;
-static int bufUsed, bufSize;
 
 static void doCommands(void);
 static void subCommand(const char *cmd, int num1, int num2);
-static int getNum(const char **retcp, int *retHaveNum, int *retNum);
+static int getNum(const char **retcp, smallint *retHaveNum, int *retNum);
 static int setCurNum(int num);
-static int initEdit(void);
-static void termEdit(void);
 static void addLines(int num);
 static int insertLine(int num, const char *data, int len);
-static int deleteLines(int num1, int num2);
+static void deleteLines(int num1, int num2);
 static int printLines(int num1, int num2, int expandFlag);
 static int writeLines(const char *file, int num1, int num2);
 static int readLines(const char *file, int num);
 static int searchLines(const char *str, int num1, int num2);
 static LINE *findLine(int num);
-
 static int findString(const LINE *lp, const char * str, int len, int offset);
 
+
+static int bad_nums(int num1, int num2, const char *for_what)
+{
+	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
+		bb_error_msg("bad line range for %s", for_what);
+		return 1;
+	}
+	return 0;
+}
+
+
+static char *skip_blank(const char *cp)
+{
+// NB: fix comment in skip_whitespace!
+	while (isblank(*cp))
+		cp++;
+	return (char *)cp;
+}
+
+
 int ed_main(int argc, char **argv);
 int ed_main(int argc, char **argv)
 {
-	if (!initEdit())
-		return EXIT_FAILURE;
-
-	if (argc > 1) {
-		fileName = strdup(argv[1]);
+	INIT_G();
 
-		if (fileName == NULL) {
-			bb_error_msg("no memory");
-			termEdit();
-			return EXIT_SUCCESS;
-		}
+	bufSize = INITBUF_SIZE;
+	bufBase = xmalloc(bufSize);
+	bufPtr = bufBase;
+	lines.next = &lines;
+	lines.prev = &lines;
 
+	if (argc > 1) {
+		fileName = xstrdup(argv[1]);
 		if (!readLines(fileName, 1)) {
-			termEdit();
 			return EXIT_SUCCESS;
 		}
-
 		if (lastNum)
 			setCurNum(1);
-
 		dirty = FALSE;
 	}
 
 	doCommands();
-
-	termEdit();
 	return EXIT_SUCCESS;
 }
 
@@ -85,42 +121,25 @@ static void doCommands(void)
 {
 	const char *cp;
 	char *endbuf, *newname, buf[USERSIZE];
-	int len, num1, num2, have1, have2;
+	int len, num1, num2;
+	smallint have1, have2;
 
 	while (TRUE) {
-		printf(": ");
-		fflush(stdout);
-
-		if (fgets(buf, sizeof(buf), stdin) == NULL)
-			return;
-
-		len = strlen(buf);
-
-		if (len == 0)
+// NB: fix comment in lineedit.c!
+		/* Returns:
+		 * -1 on read errors or EOF, or on bare Ctrl-D.
+		 * 0  on ctrl-C,
+		 * >0 length of input string, including terminating '\n'
+		 */
+		len = read_line_input(": ", buf, sizeof(buf), NULL);
+		if (len <= 0)
 			return;
-
 		endbuf = &buf[len - 1];
-
-		if (*endbuf != '\n') {
-			bb_error_msg("command line too long");
-
-			do {
-				len = fgetc(stdin);
-			} while ((len != EOF) && (len != '\n'));
-
-			continue;
-		}
-
 		while ((endbuf > buf) && isblank(endbuf[-1]))
 			endbuf--;
-
 		*endbuf = '\0';
 
-		cp = buf;
-
-		while (isblank(*cp))
-			cp++;
-
+		cp = skip_blank(buf);
 		have1 = FALSE;
 		have2 = FALSE;
 
@@ -132,28 +151,21 @@ static void doCommands(void)
 		if (!getNum(&cp, &have1, &num1))
 			continue;
 
-		while (isblank(*cp))
-			cp++;
+		cp = skip_blank(cp);
 
 		if (*cp == ',') {
 			cp++;
-
 			if (!getNum(&cp, &have2, &num2))
 				continue;
-
 			if (!have1)
 				num1 = 1;
-
 			if (!have2)
 				num2 = lastNum;
-
 			have1 = TRUE;
 			have2 = TRUE;
 		}
-
 		if (!have1)
 			num1 = curNum;
-
 		if (!have2)
 			num2 = num1;
 
@@ -176,10 +188,7 @@ static void doCommands(void)
 					bb_error_msg("bad file command");
 					break;
 				}
-
-				while (isblank(*cp))
-					cp++;
-
+				cp = skip_blank(cp);
 				if (*cp == '\0') {
 					if (fileName)
 						printf("\"%s\"\n", fileName);
@@ -187,17 +196,12 @@ static void doCommands(void)
 						printf("No file name\n");
 					break;
 				}
-
 				newname = strdup(cp);
-
 				if (newname == NULL) {
 					bb_error_msg("no memory for file name");
 					break;
 				}
-
-				if (fileName)
-					free(fileName);
-
+				free(fileName);
 				fileName = newname;
 				break;
 
@@ -206,14 +210,11 @@ static void doCommands(void)
 				break;
 
 			case 'k':
-				while (isblank(*cp))
-					cp++;
-
-				if ((*cp < 'a') || (*cp > 'a') || cp[1]) {
+				cp = skip_blank(cp);
+				if ((*cp < 'a') || (*cp > 'z') || cp[1]) {
 					bb_error_msg("bad mark name");
 					break;
 				}
-
 				marks[*cp - 'a'] = num2;
 				break;
 
@@ -226,30 +227,20 @@ static void doCommands(void)
 				break;
 
 			case 'q':
-				while (isblank(*cp))
-					cp++;
-
+				cp = skip_blank(cp);
 				if (have1 || *cp) {
 					bb_error_msg("bad quit command");
 					break;
 				}
-
 				if (!dirty)
 					return;
-
-				printf("Really quit? ");
-				fflush(stdout);
-
-				buf[0] = '\0';
-				fgets(buf, sizeof(buf), stdin);
-				cp = buf;
-
-				while (isblank(*cp))
-					cp++;
-
-				if ((*cp == 'y') || (*cp == 'Y'))
+				len = read_line_input("Really quit? ", buf, 16, NULL);
+				/* read error/EOF - no way to continue */
+				if (len < 0)
+					return;
+				cp = skip_blank(buf);
+				if ((*cp | 0x20) == 'y') /* Y or y */
 					return;
-
 				break;
 
 			case 'r':
@@ -257,24 +248,17 @@ static void doCommands(void)
 					bb_error_msg("bad read command");
 					break;
 				}
-
-				while (isblank(*cp))
-					cp++;
-
+				cp = skip_blank(cp);
 				if (*cp == '\0') {
 					bb_error_msg("no file name");
 					break;
 				}
-
 				if (!have1)
 					num1 = lastNum;
-
 				if (readLines(cp, num1 + 1))
 					break;
-
 				if (fileName == NULL)
 					fileName = strdup(cp);
-
 				break;
 
 			case 's':
@@ -286,36 +270,30 @@ static void doCommands(void)
 					bb_error_msg("bad write command");
 					break;
 				}
-
-				while (isblank(*cp))
-					cp++;
-
+				cp = skip_blank(cp);
 				if (!have1) {
 					num1 = 1;
 					num2 = lastNum;
 				}
-
 				if (*cp == '\0')
 					cp = fileName;
-
 				if (cp == NULL) {
 					bb_error_msg("no file name specified");
 					break;
 				}
-
 				writeLines(cp, num1, num2);
 				break;
 
 			case 'z':
 				switch (*cp) {
 				case '-':
-					printLines(curNum-21, curNum, FALSE);
+					printLines(curNum - 21, curNum, FALSE);
 					break;
 				case '.':
-					printLines(curNum-11, curNum+10, FALSE);
+					printLines(curNum - 11, curNum + 10, FALSE);
 					break;
 				default:
-					printLines(curNum, curNum+21, FALSE);
+					printLines(curNum, curNum + 21, FALSE);
 					break;
 				}
 				break;
@@ -325,29 +303,24 @@ static void doCommands(void)
 					bb_error_msg("no arguments allowed");
 					break;
 				}
-
 				printLines(curNum, curNum, FALSE);
 				break;
 
 			case '-':
 				if (setCurNum(curNum - 1))
 					printLines(curNum, curNum, FALSE);
-
 				break;
 
 			case '=':
 				printf("%d\n", num1);
 				break;
-
 			case '\0':
 				if (have1) {
 					printLines(num2, num2, FALSE);
 					break;
 				}
-
 				if (setCurNum(curNum + 1))
 					printLines(curNum, curNum, FALSE);
-
 				break;
 
 			default:
@@ -362,17 +335,15 @@ static void doCommands(void)
  * Do the substitute command.
  * The current line is set to the last substitution done.
  */
-static void subCommand(const char * cmd, int num1, int num2)
+static void subCommand(const char *cmd, int num1, int num2)
 {
 	char *cp, *oldStr, *newStr, buf[USERSIZE];
 	int delim, oldLen, newLen, deltaLen, offset;
 	LINE *lp, *nlp;
 	int globalFlag, printFlag, didSub, needPrint;
 
-	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
-		bb_error_msg("bad line range for substitute");
+	if (bad_nums(num1, num2, "substitute"))
 		return;
-	}
 
 	globalFlag = FALSE;
 	printFlag = FALSE;
@@ -394,7 +365,6 @@ static void subCommand(const char * cmd, int num1, int num2)
 	oldStr = cp;
 
 	cp = strchr(cp, delim);
-
 	if (cp == NULL) {
 		bb_error_msg("missing 2nd delimiter for substitute");
 		return;
@@ -414,11 +384,9 @@ static void subCommand(const char * cmd, int num1, int num2)
 		case 'g':
 			globalFlag = TRUE;
 			break;
-
 		case 'p':
 			printFlag = TRUE;
 			break;
-
 		default:
 			bb_error_msg("unknown option for substitute");
 			return;
@@ -429,7 +397,6 @@ static void subCommand(const char * cmd, int num1, int num2)
 			bb_error_msg("no previous search string");
 			return;
 		}
-
 		oldStr = searchString;
 	}
 
@@ -437,7 +404,6 @@ static void subCommand(const char * cmd, int num1, int num2)
 		strcpy(searchString, oldStr);
 
 	lp = findLine(num1);
-
 	if (lp == NULL)
 		return;
 
@@ -455,11 +421,9 @@ static void subCommand(const char * cmd, int num1, int num2)
 				printLines(num1, num1, FALSE);
 				needPrint = FALSE;
 			}
-
 			offset = 0;
 			lp = lp->next;
 			num1++;
-
 			continue;
 		}
 
@@ -473,7 +437,6 @@ static void subCommand(const char * cmd, int num1, int num2)
 		 */
 		if (deltaLen <= 0) {
 			memcpy(&lp->data[offset], newStr, newLen);
-
 			if (deltaLen) {
 				memcpy(&lp->data[offset + newLen],
 					&lp->data[offset + oldLen],
@@ -481,20 +444,15 @@ static void subCommand(const char * cmd, int num1, int num2)
 
 				lp->len += deltaLen;
 			}
-
 			offset += newLen;
-
 			if (globalFlag)
 				continue;
-
 			if (needPrint) {
 				printLines(num1, num1, FALSE);
 				needPrint = FALSE;
 			}
-
 			lp = lp->next;
 			num1++;
-
 			continue;
 		}
 
@@ -503,8 +461,7 @@ static void subCommand(const char * cmd, int num1, int num2)
 		 * structure and use that.  Link it in in place of
 		 * the old line structure.
 		 */
-		nlp = (LINE *) malloc(sizeof(LINE) + lp->len + deltaLen);
-
+		nlp = malloc(sizeof(LINE) + lp->len + deltaLen);
 		if (nlp == NULL) {
 			bb_error_msg("cannot get memory for line");
 			return;
@@ -513,9 +470,7 @@ static void subCommand(const char * cmd, int num1, int num2)
 		nlp->len = lp->len + deltaLen;
 
 		memcpy(nlp->data, lp->data, offset);
-
 		memcpy(&nlp->data[offset], newStr, newLen);
-
 		memcpy(&nlp->data[offset + newLen],
 			&lp->data[offset + oldLen],
 			lp->len - offset - oldLen);
@@ -554,7 +509,7 @@ static void subCommand(const char * cmd, int num1, int num2)
  * Search a line for the specified string starting at the specified
  * offset in the line.  Returns the offset of the found string, or -1.
  */
-static int findString( const LINE * lp, const char * str, int len, int offset)
+static int findString(const LINE *lp, const char *str, int len, int offset)
 {
 	int left;
 	const char *cp, *ncp;
@@ -564,20 +519,14 @@ static int findString( const LINE * lp, const char * str, int len, int offset)
 
 	while (left >= len) {
 		ncp = memchr(cp, *str, left);
-
 		if (ncp == NULL)
 			return -1;
-
 		left -= (ncp - cp);
-
 		if (left < len)
 			return -1;
-
 		cp = ncp;
-
 		if (memcmp(cp, str, len) == 0)
 			return (cp - lp->data);
-
 		cp++;
 		left--;
 	}
@@ -597,23 +546,20 @@ static void addLines(int num)
 	int len;
 	char buf[USERSIZE + 1];
 
-	while (fgets(buf, sizeof(buf), stdin)) {
-		if ((buf[0] == '.') && (buf[1] == '\n') && (buf[2] == '\0'))
-			return;
-
-		len = strlen(buf);
-
-		if (len == 0)
-			return;
-
-		if (buf[len - 1] != '\n') {
-			bb_error_msg("line too long");
-			do {
-				len = fgetc(stdin);
-			} while ((len != EOF) && (len != '\n'));
+	while (1) {
+		/* Returns:
+		 * -1 on read errors or EOF, or on bare Ctrl-D.
+		 * 0  on ctrl-C,
+		 * >0 length of input string, including terminating '\n'
+		 */
+		len = read_line_input("", buf, sizeof(buf), NULL);
+		if (len <= 0) {
+			/* Previously, ctrl-C was exiting to shell.
+			 * Now we exit to ed prompt. Is in important? */
 			return;
 		}
-
+		if ((buf[0] == '.') && (buf[1] == '\n') && (buf[2] == '\0'))
+			return;
 		if (!insertLine(num++, buf, len))
 			return;
 	}
@@ -628,20 +574,20 @@ static void addLines(int num)
  * Whether there was a number is returned indirectly, as is the number.
  * The character pointer which stopped the scan is also returned.
  */
-static int getNum(const char **retcp, int *retHaveNum, int *retNum)
+static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
 {
 	const char *cp;
 	char *endStr, str[USERSIZE];
-	int haveNum, value, num, sign;
+	int value, num;
+	smallint haveNum, minus;
 
 	cp = *retcp;
-	haveNum = FALSE;
 	value = 0;
-	sign = 1;
+	haveNum = FALSE;
+	minus = 0;
 
 	while (TRUE) {
-		while (isblank(*cp))
-			cp++;
+		cp = skip_blank(cp);
 
 		switch (*cp) {
 			case '.':
@@ -658,12 +604,10 @@ static int getNum(const char **retcp, int *retHaveNum, int *retNum)
 
 			case '\'':
 				cp++;
-
 				if ((*cp < 'a') || (*cp > 'z')) {
 					bb_error_msg("bad mark name");
 					return FALSE;
 				}
-
 				haveNum = TRUE;
 				num = marks[*cp++ - 'a'];
 				break;
@@ -671,19 +615,14 @@ static int getNum(const char **retcp, int *retHaveNum, int *retNum)
 			case '/':
 				strcpy(str, ++cp);
 				endStr = strchr(str, '/');
-
 				if (endStr) {
 					*endStr++ = '\0';
 					cp += (endStr - str);
-				}
-				else
+				} else
 					cp = "";
-
 				num = searchLines(str, curNum, lastNum);
-
 				if (num == 0)
 					return FALSE;
-
 				haveNum = TRUE;
 				break;
 
@@ -694,29 +633,25 @@ static int getNum(const char **retcp, int *retHaveNum, int *retNum)
 					*retNum = value;
 					return TRUE;
 				}
-
 				num = 0;
-
 				while (isdigit(*cp))
 					num = num * 10 + *cp++ - '0';
-
 				haveNum = TRUE;
 				break;
 		}
 
-		value += num * sign;
+		value += (minus ? -num : num);
 
-		while (isblank(*cp))
-			cp++;
+		cp = skip_blank(cp);
 
 		switch (*cp) {
 			case '-':
-				sign = -1;
+				minus = 1;
 				cp++;
 				break;
 
 			case '+':
-				sign = 1;
+				minus = 0;
 				cp++;
 				break;
 
@@ -731,74 +666,10 @@ static int getNum(const char **retcp, int *retHaveNum, int *retNum)
 
 
 /*
- * Initialize everything for editing.
- */
-static int initEdit(void)
-{
-	int i;
-
-	bufSize = INITBUF_SIZE;
-	bufBase = malloc(bufSize);
-
-	if (bufBase == NULL) {
-		bb_error_msg("no memory for buffer");
-		return FALSE;
-	}
-
-	bufPtr = bufBase;
-	bufUsed = 0;
-
-	lines.next = &lines;
-	lines.prev = &lines;
-
-	curLine = NULL;
-	curNum = 0;
-	lastNum = 0;
-	dirty = FALSE;
-	fileName = NULL;
-	searchString[0] = '\0';
-
-	for (i = 0; i < 26; i++)
-		marks[i] = 0;
-
-	return TRUE;
-}
-
-
-/*
- * Finish editing.
- */
-static void termEdit(void)
-{
-	if (bufBase)
-		free(bufBase);
-
-	bufBase = NULL;
-	bufPtr = NULL;
-	bufSize = 0;
-	bufUsed = 0;
-
-	if (fileName)
-		free(fileName);
-
-	fileName = NULL;
-
-	searchString[0] = '\0';
-
-	if (lastNum)
-		deleteLines(1, lastNum);
-
-	lastNum = 0;
-	curNum = 0;
-	curLine = NULL;
-}
-
-
-/*
  * Read lines from a file at the specified line number.
  * Returns TRUE if the file was successfully read.
  */
-static int readLines(const char * file, int num)
+static int readLines(const char *file, int num)
 {
 	int fd, cc;
 	int len, lineCount, charCount;
@@ -810,7 +681,6 @@ static int readLines(const char * file, int num)
 	}
 
 	fd = open(file, 0);
-
 	if (fd < 0) {
 		perror(file);
 		return FALSE;
@@ -830,18 +700,15 @@ static int readLines(const char * file, int num)
 
 		if (cp) {
 			len = (cp - bufPtr) + 1;
-
 			if (!insertLine(num, bufPtr, len)) {
 				close(fd);
 				return FALSE;
 			}
-
 			bufPtr += len;
 			bufUsed -= len;
 			charCount += len;
 			lineCount++;
 			num++;
-
 			continue;
 		}
 
@@ -853,19 +720,17 @@ static int readLines(const char * file, int num)
 		if (bufUsed >= bufSize) {
 			len = (bufSize * 3) / 2;
 			cp = realloc(bufBase, len);
-
 			if (cp == NULL) {
 				bb_error_msg("no memory for buffer");
 				close(fd);
 				return FALSE;
 			}
-
 			bufBase = cp;
 			bufPtr = bufBase + bufUsed;
 			bufSize = len;
 		}
 
-		cc = read(fd, bufPtr, bufSize - bufUsed);
+		cc = safe_read(fd, bufPtr, bufSize - bufUsed);
 		bufUsed += cc;
 		bufPtr = bufBase;
 
@@ -882,7 +747,6 @@ static int readLines(const char * file, int num)
 			close(fd);
 			return -1;
 		}
-
 		lineCount++;
 		charCount += bufUsed;
 	}
@@ -900,21 +764,18 @@ static int readLines(const char * file, int num)
  * Write the specified lines out to the specified file.
  * Returns TRUE if successful, or FALSE on an error with a message output.
  */
-static int writeLines(const char * file, int num1, int num2)
+static int writeLines(const char *file, int num1, int num2)
 {
 	LINE *lp;
 	int fd, lineCount, charCount;
 
-	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
-		bb_error_msg("bad line range for write");
+	if (bad_nums(num1, num2, "write"))
 		return FALSE;
-	}
 
 	lineCount = 0;
 	charCount = 0;
 
 	fd = creat(file, 0666);
-
 	if (fd < 0) {
 		perror(file);
 		return FALSE;
@@ -924,19 +785,17 @@ static int writeLines(const char * file, int num1, int num2)
 	fflush(stdout);
 
 	lp = findLine(num1);
-
 	if (lp == NULL) {
 		close(fd);
 		return FALSE;
 	}
 
 	while (num1++ <= num2) {
-		if (write(fd, lp->data, lp->len) != lp->len) {
+		if (full_write(fd, lp->data, lp->len) != lp->len) {
 			perror(file);
 			close(fd);
 			return FALSE;
 		}
-
 		charCount += lp->len;
 		lineCount++;
 		lp = lp->next;
@@ -964,13 +823,10 @@ static int printLines(int num1, int num2, int expandFlag)
 	const char *cp;
 	int ch, count;
 
-	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
-		bb_error_msg("bad line range for print");
+	if (bad_nums(num1, num2, "print"))
 		return FALSE;
-	}
 
 	lp = findLine(num1);
-
 	if (lp == NULL)
 		return FALSE;
 
@@ -979,7 +835,6 @@ static int printLines(int num1, int num2, int expandFlag)
 			write(1, lp->data, lp->len);
 			setCurNum(num1++);
 			lp = lp->next;
-
 			continue;
 		}
 
@@ -995,22 +850,18 @@ static int printLines(int num1, int num2, int expandFlag)
 
 		while (count-- > 0) {
 			ch = *cp++;
-
 			if (ch & 0x80) {
 				fputs("M-", stdout);
 				ch &= 0x7f;
 			}
-
 			if (ch < ' ') {
 				fputc('^', stdout);
 				ch += '@';
 			}
-
 			if (ch == 0x7f) {
 				fputc('^', stdout);
 				ch = '?';
 			}
-
 			fputc(ch, stdout);
 		}
 
@@ -1031,7 +882,7 @@ static int printLines(int num1, int num2, int expandFlag)
  * The inserted line is also set to become the current line.
  * Returns TRUE if successful.
  */
-static int insertLine(int num, const char * data, int len)
+static int insertLine(int num, const char *data, int len)
 {
 	LINE *newLp, *lp;
 
@@ -1041,7 +892,6 @@ static int insertLine(int num, const char * data, int len)
 	}
 
 	newLp = malloc(sizeof(LINE) + len - 1);
-
 	if (newLp == NULL) {
 		bb_error_msg("failed to allocate memory for line");
 		return FALSE;
@@ -1054,7 +904,6 @@ static int insertLine(int num, const char * data, int len)
 		lp = &lines;
 	else {
 		lp = findLine(num);
-
 		if (lp == NULL) {
 			free((char *) newLp);
 			return FALSE;
@@ -1075,20 +924,17 @@ static int insertLine(int num, const char * data, int len)
 /*
  * Delete lines from the given range.
  */
-static int deleteLines(int num1, int num2)
+static void deleteLines(int num1, int num2)
 {
 	LINE *lp, *nlp, *plp;
 	int count;
 
-	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
-		bb_error_msg("bad line numbers for delete");
-		return FALSE;
-	}
+	if (bad_nums(num1, num2, "delete"))
+		return;
 
 	lp = findLine(num1);
-
 	if (lp == NULL)
-		return FALSE;
+		return;
 
 	if ((curNum >= num1) && (curNum <= num2)) {
 		if (num2 < lastNum)
@@ -1100,10 +946,8 @@ static int deleteLines(int num1, int num2)
 	}
 
 	count = num2 - num1 + 1;
-
 	if (curNum > num2)
 		curNum -= count;
-
 	lastNum -= count;
 
 	while (count-- > 0) {
@@ -1111,22 +955,17 @@ static int deleteLines(int num1, int num2)
 		plp = lp->prev;
 		plp->next = nlp;
 		nlp->prev = plp;
-		lp->next = NULL;
-		lp->prev = NULL;
-		lp->len = 0;
 		free(lp);
 		lp = nlp;
 	}
 
 	dirty = TRUE;
-
-	return TRUE;
 }
 
 
 /*
  * Search for a line which contains the specified string.
- * If the string is NULL, then the previously searched for string
+ * If the string is "", then the previously searched for string
  * is used.  The currently searched for string is saved for future use.
  * Returns the line number which matches, or 0 if there was no match
  * with an error printed.
@@ -1136,17 +975,14 @@ static int searchLines(const char *str, int num1, int num2)
 	const LINE *lp;
 	int len;
 
-	if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
-		bb_error_msg("bad line numbers for search");
+	if (bad_nums(num1, num2, "search"))
 		return 0;
-	}
 
 	if (*str == '\0') {
 		if (searchString[0] == '\0') {
 			bb_error_msg("no previous search string");
 			return 0;
 		}
-
 		str = searchString;
 	}
 
@@ -1156,14 +992,12 @@ static int searchLines(const char *str, int num1, int num2)
 	len = strlen(str);
 
 	lp = findLine(num1);
-
 	if (lp == NULL)
 		return 0;
 
 	while (num1 <= num2) {
 		if (findString(lp, str, len, 0) >= 0)
 			return num1;
-
 		num1++;
 		lp = lp->next;
 	}
@@ -1196,12 +1030,10 @@ static LINE *findLine(int num)
 
 	lp = curLine;
 	lnum = curNum;
-
 	if (num < (curNum / 2)) {
 		lp = lines.next;
 		lnum = 1;
-	}
-	else if (num > ((curNum + lastNum) / 2)) {
+	} else if (num > ((curNum + lastNum) / 2)) {
 		lp = lines.prev;
 		lnum = lastNum;
 	}
@@ -1228,10 +1060,8 @@ static int setCurNum(int num)
 	LINE *lp;
 
 	lp = findLine(num);
-
 	if (lp == NULL)
 		return FALSE;
-
 	curNum = num;
 	curLine = lp;
 	return TRUE;