ed: large cleanup
[people/mcb30/busybox.git] / editors / ed.c
index e6576b4..f5b9c39 100644 (file)
@@ -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;
 
@@ -730,75 +665,11 @@ 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;