less: somewhat buggy applet, but nice. Muchly reduced
authorDenis Vlasenko <vda.linux@googlemail.com>
Wed, 20 Dec 2006 02:46:48 +0000 (02:46 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Wed, 20 Dec 2006 02:46:48 +0000 (02:46 -0000)
xstrdup'ing and memory consumption. Made linewrap saner.
regex matching code was awful - still buggy, but not as
leaky as before. Made buffer size configurable. Killed
several static and on-stack buffers. Hopefully eliminated
staircase effect on Ctrl-C (unable to reproduce).

libbb/get_line_from_file.c
miscutils/Config.in
miscutils/less.c

index 3f2c609..a27693f 100644 (file)
@@ -13,7 +13,7 @@
 
 /* This function reads an entire line from a text file, up to a newline 
  * or NUL byte, inclusive.  It returns a malloc'ed char * which must be
- * stored and free'ed  by the caller.  If end is null '\n' isn't considered
+ * stored and free'ed by the caller.  If end is null '\n' isn't considered
  * end of line.  If end isn't null, length of the chunk read is stored in it. */
 
 char *bb_get_chunk_from_file(FILE * file, int *end)
@@ -62,7 +62,7 @@ char *xmalloc_getline(FILE * file)
        char *c = bb_get_chunk_from_file(file, &i);
 
        if (i && c[--i] == '\n')
-               c[i] = 0;
+               c[i] = '\0';
 
        return c;
 }
index 90e2b6f..01d1fa0 100644 (file)
@@ -133,6 +133,11 @@ config LESS
          'less' is a pager, meaning that it displays text files. It possesses
          a wide array of features, and is an improvement over 'more'.
 
+config FEATURE_LESS_MAXLINES
+       int "Max number of input lines less will try to eat"
+       default 9999999
+       depends on LESS
+
 config FEATURE_LESS_BRACKETS
        bool "Enable bracket searching"
        default y
index 03ffd78..7350067 100644 (file)
@@ -32,7 +32,7 @@
 
 #include "busybox.h"
 
-#ifdef CONFIG_FEATURE_LESS_REGEXP
+#if ENABLE_FEATURE_LESS_REGEXP
 #include "xregex.h"
 #endif
 
 /* The escape code to clear the screen */
 #define CLEAR "\033[H\033[J"
 
-/* Maximum number of lines in a file */
-#define MAXLINES 10000
+#define MAXLINES CONFIG_FEATURE_LESS_MAXLINES
 
 static int height;
 static int width;
 static char **files;
-static char filename[256];
+static char *filename;
 static char **buffer;
 static char **flines;
 static int current_file = 1;
@@ -79,24 +78,21 @@ static int num_flines;
 static int num_files = 1;
 
 /* Command line options */
-static unsigned flags;
 #define FLAG_E 1
 #define FLAG_M (1<<1)
 #define FLAG_m (1<<2)
 #define FLAG_N (1<<3)
 #define FLAG_TILDE (1<<4)
 /* hijack command line options variable for internal state vars */
-#define LESS_STATE_INP_STDIN (1<<5)
-#define LESS_STATE_PAST_EOF  (1<<6)
-#define LESS_STATE_MATCH_BACKWARDS (1<<7)
-/* INP_STDIN is used to change behaviour when input comes from stdin */
+#define LESS_STATE_PAST_EOF  (1<<5)
+#define LESS_STATE_MATCH_BACKWARDS (1<<6)
 
-#ifdef CONFIG_FEATURE_LESS_MARKS
+#if ENABLE_FEATURE_LESS_MARKS
 static int mark_lines[15][2];
 static int num_marks;
 #endif
 
-#ifdef CONFIG_FEATURE_LESS_REGEXP
+#if ENABLE_FEATURE_LESS_REGEXP
 static int match_found;
 static int *match_lines;
 static int match_pos;
@@ -143,7 +139,7 @@ static int tless_getch(void)
           them accordingly */
 
        if (input == '\033' && getc(inp) == '[') {
-               unsigned int i;
+               unsigned i;
                input = getc(inp);
                set_tty_cooked();
 
@@ -152,13 +148,12 @@ static int tless_getch(void)
                        return 20 + i;
                else if ((i = input - REAL_PAGE_UP) < 4)
                        return 24 + i;
+               else
+                       return 0; /* ?? */
        }
        /* The input is a normal ASCII value */
-       else {
-               set_tty_cooked();
-               return input;
-       }
-       return 0;
+       set_tty_cooked();
+       return input;
 }
 
 /* Move the cursor to a position (x,y), where (0,0) is the
@@ -174,51 +169,62 @@ static void clear_line(void)
        printf("\033[K");
 }
 
-/* This adds line numbers to every line, as the -N flag necessitates */
-static void add_linenumbers(void)
-{
-       int i;
-
-       for (i = 0; i <= num_flines; i++) {
-               char *new = xasprintf("%5d %s", i + 1, flines[i]);
-               free(flines[i]);
-               flines[i] = new;
-       }
-}
-
 static void data_readlines(void)
 {
-       int i;
-       char current_line[256];
+       unsigned i;
+       unsigned n = 1;
+       int w = width;
+       char *last_nl = (char*)1; /* "not NULL" */
+       char *current_line;
        FILE *fp;
 
-       fp = (flags & LESS_STATE_INP_STDIN) ? stdin : xfopen(filename, "r");
+       fp = filename ? xfopen(filename, "r") : stdin;
        flines = NULL;
-       for (i = 0; (feof(fp)==0) && (i <= MAXLINES); i++) {
-               strcpy(current_line, "");
-               fgets(current_line, 256, fp);
+       if (option_mask32 & FLAG_N) {
+               w -= 6;
+               if (w < 1) w = 1; /* paranoia */
+       }
+       for (i = 0; !feof(fp) && i <= MAXLINES; i++) {
+               flines = xrealloc(flines, (i+1) * sizeof(char *));
+
+               current_line = xmalloc(w);
+ again:
+               current_line[0] = '\0';
+               fgets(current_line, w, fp);
                if (fp != stdin)
                        die_if_ferror(fp, filename);
-               flines = xrealloc(flines, (i+1) * sizeof(char *));
-               flines[i] = xstrdup(current_line);
+
+               /* Corner case: linewrap with only '\n' wrapping */
+               /* Looks ugly on screen, so we handle it specially */
+               if (!last_nl && current_line[0] == '\n') {
+                       last_nl = (char*)1; /* "not NULL" */
+                       n++;
+                       goto again;
+               }
+               last_nl = last_char_is(current_line, '\n');
+               if (last_nl)
+                       *last_nl = '\0';
+               if (option_mask32 & FLAG_N) {
+                       flines[i] = xasprintf((n <= 99999) ? "%5u %s" : "%05u %s",
+                                               n % 100000, current_line);
+                       free(current_line);
+                       if (last_nl)
+                               n++;
+               } else {
+                       flines[i] = xrealloc(current_line, strlen(current_line)+1);
+               }
        }
        num_flines = i - 2;
 
        /* Reset variables for a new file */
 
        line_pos = 0;
-       flags &= ~LESS_STATE_PAST_EOF;
+       option_mask32 &= ~LESS_STATE_PAST_EOF;
 
        fclose(fp);
-
-       if (inp == NULL)
-               inp = (flags & LESS_STATE_INP_STDIN) ? xfopen(CURRENT_TTY, "r") : stdin;
-
-       if (flags & FLAG_N)
-               add_linenumbers();
 }
 
-#ifdef CONFIG_FEATURE_LESS_FLAGS
+#if ENABLE_FEATURE_LESS_FLAGS
 
 /* Interestingly, writing calc_percent as a function and not a prototype saves around 32 bytes
  * on my build. */
@@ -232,19 +238,18 @@ static void m_status_print(void)
 {
        int percentage;
 
-       if (!(flags & LESS_STATE_PAST_EOF)) {
+       if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
                if (!line_pos) {
-                       if (num_files > 1)
+                       if (num_files > 1) {
                                printf("%s%s %s%i%s%i%s%i-%i/%i ", HIGHLIGHT,
                                        filename, "(file ", current_file, " of ", num_files, ") lines ",
                                        line_pos + 1, line_pos + height - 1, num_flines + 1);
-                       else {
+                       else {
                                printf("%s%s lines %i-%i/%i ", HIGHLIGHT,
                                        filename, line_pos + 1, line_pos + height - 1,
                                        num_flines + 1);
                        }
-               }
-               else {
+               } else {
                        printf("%s %s lines %i-%i/%i ", HIGHLIGHT, filename,
                                line_pos + 1, line_pos + height - 1, num_flines + 1);
                }
@@ -253,13 +258,11 @@ static void m_status_print(void)
                        printf("(END) %s", NORMAL);
                        if ((num_files > 1) && (current_file != num_files))
                                printf("%s- Next: %s%s", HIGHLIGHT, files[current_file], NORMAL);
-               }
-               else {
+               } else {
                        percentage = calc_percent();
                        printf("%i%% %s", percentage, NORMAL);
                }
-       }
-       else {
+       } else {
                printf("%s%s lines %i-%i/%i (END) ", HIGHLIGHT, filename,
                                line_pos + 1, num_flines + 1, num_flines + 1);
                if ((num_files > 1) && (current_file != num_files))
@@ -287,10 +290,10 @@ static void medium_status_print(void)
 static void status_print(void)
 {
        /* Change the status if flags have been set */
-#ifdef CONFIG_FEATURE_LESS_FLAGS
-       if (flags & FLAG_M)
+#if ENABLE_FEATURE_LESS_FLAGS
+       if (option_mask32 & FLAG_M)
                m_status_print();
-       else if (flags & FLAG_m)
+       else if (option_mask32 & FLAG_m)
                medium_status_print();
        /* No flags set */
        else {
@@ -300,16 +303,14 @@ static void status_print(void)
                        if (num_files > 1)
                                printf("%s%s%i%s%i%s%s", HIGHLIGHT, "(file ",
                                        current_file, " of ", num_files, ")", NORMAL);
-               }
-               else if (line_pos == num_flines - height + 2) {
+               } else if (line_pos == num_flines - height + 2) {
                        printf("%s%s %s", HIGHLIGHT, "(END)", NORMAL);
                        if ((num_files > 1) && (current_file != num_files))
                                printf("%s%s%s%s", HIGHLIGHT, "- Next: ", files[current_file], NORMAL);
-               }
-               else {
+               } else {
                        putchar(':');
                }
-#ifdef CONFIG_FEATURE_LESS_FLAGS
+#if ENABLE_FEATURE_LESS_FLAGS
        }
 #endif
 }
@@ -322,13 +323,12 @@ static void buffer_print(void)
        printf("%s", CLEAR);
        if (num_flines >= height - 2) {
                for (i = 0; i < height - 1; i++)
-                       printf("%s", buffer[i]);
-       }
-       else {
+                       printf("%.*s\n", width, buffer[i]);
+       } else {
                for (i = 1; i < (height - 1 - num_flines); i++)
                        putchar('\n');
                for (i = 0; i < height - 1; i++)
-                       printf("%s", buffer[i]);
+                       printf("%.*s\n", width, buffer[i]);
        }
 
        status_print();
@@ -341,21 +341,18 @@ static void buffer_init(void)
 
        if (buffer == NULL) {
                /* malloc the number of lines needed for the buffer */
-               buffer = xrealloc(buffer, height * sizeof(char *));
-       } else {
-               for (i = 0; i < (height - 1); i++)
-                       free(buffer[i]);
+               buffer = xmalloc(height * sizeof(char *));
        }
 
        /* Fill the buffer until the end of the file or the
           end of the buffer is reached */
        for (i = 0; (i < (height - 1)) && (i <= num_flines); i++) {
-               buffer[i] = xstrdup(flines[i]);
+               buffer[i] = flines[i];
        }
 
        /* If the buffer still isn't full, fill it with blank lines */
        for (; i < (height - 1); i++) {
-               buffer[i] = xstrdup("");
+               buffer[i] = "";
        }
 }
 
@@ -364,28 +361,25 @@ static void buffer_down(int nlines)
 {
        int i;
 
-       if (!(flags & LESS_STATE_PAST_EOF)) {
+       if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
                if (line_pos + (height - 3) + nlines < num_flines) {
                        line_pos += nlines;
                        for (i = 0; i < (height - 1); i++) {
-                               free(buffer[i]);
-                               buffer[i] = xstrdup(flines[line_pos + i]);
+                               buffer[i] = flines[line_pos + i];
                        }
-               }
-               else {
+               } else {
                        /* As the number of lines requested was too large, we just move
                        to the end of the file */
                        while (line_pos + (height - 3) + 1 < num_flines) {
                                line_pos += 1;
                                for (i = 0; i < (height - 1); i++) {
-                                       free(buffer[i]);
-                                       buffer[i] = xstrdup(flines[line_pos + i]);
+                                       buffer[i] = flines[line_pos + i];
                                }
                        }
                }
 
                /* We exit if the -E flag has been set */
-               if ((flags & FLAG_E) && (line_pos + (height - 2) == num_flines))
+               if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines))
                        tless_exit(0);
        }
 }
@@ -395,22 +389,19 @@ static void buffer_up(int nlines)
        int i;
        int tilde_line;
 
-       if (!(flags & LESS_STATE_PAST_EOF)) {
+       if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
                if (line_pos - nlines >= 0) {
                        line_pos -= nlines;
                        for (i = 0; i < (height - 1); i++) {
-                               free(buffer[i]);
-                               buffer[i] = xstrdup(flines[line_pos + i]);
+                               buffer[i] = flines[line_pos + i];
                        }
-               }
-               else {
+               } else {
                /* As the requested number of lines to move was too large, we
                   move one line up at a time until we can't. */
                        while (line_pos != 0) {
                                line_pos -= 1;
                                for (i = 0; i < (height - 1); i++) {
-                                       free(buffer[i]);
-                                       buffer[i] = xstrdup(flines[line_pos + i]);
+                                       buffer[i] = flines[line_pos + i];
                                }
                        }
                }
@@ -423,19 +414,17 @@ static void buffer_up(int nlines)
                /* Going backwards nlines lines has taken us to a point where
                   nothing is past the EOF, so we revert to normal. */
                if (line_pos < num_flines - height + 3) {
-                       flags &= ~LESS_STATE_PAST_EOF;
+                       option_mask32 &= ~LESS_STATE_PAST_EOF;
                        buffer_up(nlines);
-               }
-               else {
+               } else {
                        /* We only move part of the buffer, as the rest
                        is past the EOF */
                        for (i = 0; i < (height - 1); i++) {
-                               free(buffer[i]);
-                               if (i < tilde_line - nlines + 1)
-                                       buffer[i] = xstrdup(flines[line_pos + i]);
-                               else {
+                               if (i < tilde_line - nlines + 1) {
+                                       buffer[i] = flines[line_pos + i];
+                               } else {
                                        if (line_pos >= num_flines - height + 2)
-                                               buffer[i] = xstrdup("~\n");
+                                               buffer[i] = "~";
                                }
                        }
                }
@@ -445,7 +434,7 @@ static void buffer_up(int nlines)
 static void buffer_line(int linenum)
 {
        int i;
-       flags &= ~LESS_STATE_PAST_EOF;
+       option_mask32 &= ~LESS_STATE_PAST_EOF;
 
        if (linenum < 0 || linenum > num_flines) {
                clear_line();
@@ -453,23 +442,20 @@ static void buffer_line(int linenum)
        }
        else if (linenum < (num_flines - height - 2)) {
                for (i = 0; i < (height - 1); i++) {
-                       free(buffer[i]);
-                       buffer[i] = xstrdup(flines[linenum + i]);
+                       buffer[i] = flines[linenum + i];
                }
                line_pos = linenum;
                buffer_print();
-       }
-       else {
+       } else {
                for (i = 0; i < (height - 1); i++) {
-                       free(buffer[i]);
                        if (linenum + i < num_flines + 2)
-                               buffer[i] = xstrdup(flines[linenum + i]);
+                               buffer[i] = flines[linenum + i];
                        else
-                               buffer[i] = xstrdup((flags & FLAG_TILDE) ? "\n" : "~\n");
+                               buffer[i] = (option_mask32 & FLAG_TILDE) ? "" : "~";
                }
                line_pos = linenum;
                /* Set past_eof so buffer_down and buffer_up act differently */
-               flags |= LESS_STATE_PAST_EOF;
+               option_mask32 |= LESS_STATE_PAST_EOF;
                buffer_print();
        }
 }
@@ -490,22 +476,13 @@ static void reinitialise(void)
 
 static void examine_file(void)
 {
-       int newline_offset;
-
        clear_line();
        printf("Examine: ");
-       fgets(filename, 256, inp);
-
-       /* As fgets adds a newline to the end of an input string, we
-          need to remove it */
-       newline_offset = strlen(filename) - 1;
-       filename[newline_offset] = '\0';
-
-       files[num_files] = xstrdup(filename);
+       free(filename);
+       filename = xmalloc_getline(inp);
+       files[num_files] = filename;
        current_file = num_files + 1;
        num_files++;
-
-       flags &= ~LESS_STATE_INP_STDIN;
        reinitialise();
 }
 
@@ -518,10 +495,10 @@ static void change_file(int direction)
 {
        if (current_file != ((direction > 0) ? num_files : 1)) {
                current_file = direction ? current_file + direction : 1;
-               strcpy(filename, files[current_file - 1]);
+               free(filename);
+               filename = xstrdup(files[current_file - 1]);
                reinitialise();
-       }
-       else {
+       } else {
                clear_line();
                printf("%s%s%s", HIGHLIGHT, (direction > 0) ? "No next file" : "No previous file", NORMAL);
        }
@@ -537,8 +514,7 @@ static void remove_current_file(void)
                        files[i - 2] = files[i - 1];
                num_files--;
                buffer_print();
-       }
-       else {
+       } else {
                change_file(1);
                for (i = 2; i <= num_files; i++)
                        files[i - 2] = files[i - 1];
@@ -564,7 +540,7 @@ static void colon_process(void)
                case 'e':
                        examine_file();
                        break;
-#ifdef CONFIG_FEATURE_LESS_FLAGS
+#if ENABLE_FEATURE_LESS_FLAGS
                case 'f':
                        clear_line();
                        m_status_print();
@@ -587,7 +563,7 @@ static void colon_process(void)
        }
 }
 
-#ifdef CONFIG_FEATURE_LESS_REGEXP
+#if ENABLE_FEATURE_LESS_REGEXP
 /* The below two regular expression handler functions NEED development. */
 
 /* Get a regular expression from the user, and then go through the current
@@ -595,48 +571,50 @@ static void colon_process(void)
 
 static char *process_regex_on_line(char *line, regex_t *pattern, int action)
 {
+/* UNTESTED. LOOKED BUGGY AND LEAKY AS HELL. */
+/* FIXED. NEED TESTING. */
+       /* 'line' should be either returned or free()ed */
+
        /* This function takes the regex and applies it to the line.
           Each part of the line that matches has the HIGHLIGHT
           and NORMAL escape sequences placed around it by
           insert_highlights if action = 1, or has the escape sequences
           removed if action = 0, and then the line is returned. */
        int match_status;
-       char *line2 = xmalloc((sizeof(char) * (strlen(line) + 1)) + 64);
-       char *growline = "";
+       char *line2 = line;
+       char *growline = xstrdup("");
+       char *ng;
        regmatch_t match_structs;
 
-       line2 = xstrdup(line);
-
        match_found = 0;
        match_status = regexec(pattern, line2, 1, &match_structs, 0);
 
        while (match_status == 0) {
-               if (match_found == 0)
-                       match_found = 1;
-
+               match_found = 1;
                if (action) {
-                       growline = xasprintf("%s%.*s%s%.*s%s", growline,
+                       ng = xasprintf("%s%.*s%s%.*s%s", growline,
                                match_structs.rm_so, line2, HIGHLIGHT,
                                match_structs.rm_eo - match_structs.rm_so,
                                line2 + match_structs.rm_so, NORMAL);
-               }
-               else {
-                       growline = xasprintf("%s%.*s%.*s", growline,
+               } else {
+                       ng = xasprintf("%s%.*s%.*s", growline,
                                match_structs.rm_so - 4, line2,
                                match_structs.rm_eo - match_structs.rm_so,
                                line2 + match_structs.rm_so);
                }
-
+               free(growline); growline = ng;
                line2 += match_structs.rm_eo;
                match_status = regexec(pattern, line2, 1, &match_structs, REG_NOTBOL);
        }
 
-       growline = xasprintf("%s%s", growline, line2);
-
-       return (match_found ? growline : line);
-
+       if (match_found) {
+               ng = xasprintf("%s%s", growline, line2);
+               free(line);
+       } else {
+               ng = line;
+       }
        free(growline);
-       free(line2);
+       return ng;
 }
 
 static void goto_match(int match)
@@ -651,35 +629,33 @@ static void goto_match(int match)
 
 static void regex_process(void)
 {
-       char uncomp_regex[100];
-       char *current_line;
+       char *uncomp_regex;
        int i;
        int j = 0;
        regex_t pattern;
+
        /* Get the uncompiled regular expression from the user */
        clear_line();
-       putchar((flags & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
-       uncomp_regex[0] = 0;
-       fgets(uncomp_regex, sizeof(uncomp_regex), inp);
-
-       if (strlen(uncomp_regex) == 1) {
+       putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
+       uncomp_regex = xmalloc_getline(inp);
+       if (!uncomp_regex || !uncomp_regex[0]) {
+               free(uncomp_regex);
                if (num_matches)
-                       goto_match((flags & LESS_STATE_MATCH_BACKWARDS)
+                       goto_match((option_mask32 & LESS_STATE_MATCH_BACKWARDS)
                                                ? match_pos - 1 : match_pos + 1);
                else
                        buffer_print();
                return;
        }
-       uncomp_regex[strlen(uncomp_regex) - 1] = '\0';
 
        /* Compile the regex and check for errors */
        xregcomp(&pattern, uncomp_regex, 0);
+       free(uncomp_regex);
 
        if (num_matches) {
                /* Get rid of all the highlights we added previously */
                for (i = 0; i <= num_flines; i++) {
-                       current_line = process_regex_on_line(flines[i], &old_pattern, 0);
-                       flines[i] = xstrdup(current_line);
+                       flines[i] = process_regex_on_line(flines[i], &old_pattern, 0);
                }
        }
        old_pattern = pattern;
@@ -692,8 +668,7 @@ static void regex_process(void)
        match_found = 0;
        /* Run the regex on each line of the current file here */
        for (i = 0; i <= num_flines; i++) {
-               current_line = process_regex_on_line(flines[i], &pattern, 1);
-               flines[i] = xstrdup(current_line);
+               flines[i] = process_regex_on_line(flines[i], &pattern, 1);
                if (match_found) {
                        match_lines = xrealloc(match_lines, (j + 1) * sizeof(int));
                        match_lines[j] = i;
@@ -703,7 +678,7 @@ static void regex_process(void)
 
        num_matches = j;
        if ((match_lines[0] != -1) && (num_flines > height - 2)) {
-               if (flags & LESS_STATE_MATCH_BACKWARDS) {
+               if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) {
                        for (i = 0; i < num_matches; i++) {
                                if (match_lines[i] > line_pos) {
                                        match_pos = i - 1;
@@ -711,11 +686,9 @@ static void regex_process(void)
                                        break;
                                }
                        }
-               }
-               else
+               } else
                        buffer_line(match_lines[0]);
-       }
-       else
+       } else
                buffer_init();
 }
 #endif
@@ -724,9 +697,8 @@ static void number_process(int first_digit)
 {
        int i = 1;
        int num;
-       char num_input[80];
+       char num_input[sizeof(int)*4]; /* more than enough */
        char keypress;
-       char *endptr;
 
        num_input[0] = first_digit;
 
@@ -734,8 +706,11 @@ static void number_process(int first_digit)
        clear_line();
        printf(":%c", first_digit);
 
-       /* Receive input until a letter is given (max 80 chars)*/
-       while((i < 80) && (num_input[i] = tless_getch()) && isdigit(num_input[i])) {
+       /* Receive input until a letter is given */
+       while (i < sizeof(num_input)-1) {
+               num_input[i] = tless_getch();
+               if (!num_input[i] || !isdigit(num_input[i]))
+                       break;
                putchar(num_input[i]);
                i++;
        }
@@ -743,8 +718,9 @@ static void number_process(int first_digit)
        /* Take the final letter out of the digits string */
        keypress = num_input[i];
        num_input[i] = '\0';
-       num = strtol(num_input, &endptr, 10);
-       if (endptr==num_input || *endptr!='\0' || num < 1 || num > MAXLINES) {
+       num = bb_strtou(num_input, NULL, 10);
+       /* on format error, num == -1 */
+       if (num < 1 || num > MAXLINES) {
                buffer_print();
                return;
        }
@@ -764,16 +740,16 @@ static void number_process(int first_digit)
                case 'p': case '%':
                        buffer_line(((num / 100) * num_flines) - 1);
                        break;
-#ifdef CONFIG_FEATURE_LESS_REGEXP
+#if ENABLE_FEATURE_LESS_REGEXP
                case 'n':
                        goto_match(match_pos + num);
                        break;
                case '/':
-                       flags &= ~LESS_STATE_MATCH_BACKWARDS;
+                       option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
                        regex_process();
                        break;
                case '?':
-                       flags |= LESS_STATE_MATCH_BACKWARDS;
+                       option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
                        regex_process();
                        break;
 #endif
@@ -782,7 +758,7 @@ static void number_process(int first_digit)
        }
 }
 
-#ifdef CONFIG_FEATURE_LESS_FLAGCS
+#if ENABLE_FEATURE_LESS_FLAGCS
 static void flag_change(void)
 {
        int keypress;
@@ -793,16 +769,16 @@ static void flag_change(void)
 
        switch (keypress) {
                case 'M':
-                       flags ^= FLAG_M;
+                       option_mask32 ^= FLAG_M;
                        break;
                case 'm':
-                       flags ^= FLAG_m;
+                       option_mask32 ^= FLAG_m;
                        break;
                case 'E':
-                       flags ^= FLAG_E;
+                       option_mask32 ^= FLAG_E;
                        break;
                case '~':
-                       flags ^= FLAG_TILDE;
+                       option_mask32 ^= FLAG_TILDE;
                        break;
                default:
                        break;
@@ -820,19 +796,19 @@ static void show_flag_status(void)
 
        switch (keypress) {
                case 'M':
-                       flag_val = flags & FLAG_M;
+                       flag_val = option_mask32 & FLAG_M;
                        break;
                case 'm':
-                       flag_val = flags & FLAG_m;
+                       flag_val = option_mask32 & FLAG_m;
                        break;
                case '~':
-                       flag_val = flags & FLAG_TILDE;
+                       flag_val = option_mask32 & FLAG_TILDE;
                        break;
                case 'N':
-                       flag_val = flags & FLAG_N;
+                       flag_val = option_mask32 & FLAG_N;
                        break;
                case 'E':
-                       flag_val = flags & FLAG_E;
+                       flag_val = option_mask32 & FLAG_E;
                        break;
                default:
                        flag_val = 0;
@@ -855,26 +831,31 @@ static void full_repaint(void)
 
 static void save_input_to_file(void)
 {
-       char current_line[256];
+       char *current_line;
        int i;
        FILE *fp;
 
        clear_line();
        printf("Log file: ");
-       fgets(current_line, 256, inp);
-       current_line[strlen(current_line) - 1] = '\0';
-       if (strlen(current_line) > 1) {
-               fp = xfopen(current_line, "w");
+       current_line = xmalloc_getline(inp);
+       if (strlen(current_line) > 0) {
+               fp = fopen(current_line, "w");
+               free(current_line);
+               if (!fp) {
+                       printf("%s%s%s", HIGHLIGHT, "Error opening log file", NORMAL);
+                       return;
+               }
                for (i = 0; i < num_flines; i++)
-                       fprintf(fp, "%s", flines[i]);
+                       fprintf(fp, "%s\n", flines[i]);
                fclose(fp);
                buffer_print();
+               return;
        }
-       else
-               printf("%s%s%s", HIGHLIGHT, "No log file", NORMAL);
+       free(current_line);
+       printf("%s%s%s", HIGHLIGHT, "No log file", NORMAL);
 }
 
-#ifdef CONFIG_FEATURE_LESS_MARKS
+#if ENABLE_FEATURE_LESS_MARKS
 static void add_mark(void)
 {
        int letter;
@@ -892,8 +873,7 @@ static void add_mark(void)
                mark_lines[num_marks][0] = letter;
                mark_lines[num_marks][1] = line_pos;
                num_marks++;
-       }
-       else {
+       } else {
                clear_line();
                printf("%s%s%s", HIGHLIGHT, "Invalid mark letter", NORMAL);
        }
@@ -917,14 +897,13 @@ static void goto_mark(void)
                        }
                if ((num_marks == 14) && (letter != mark_lines[14][0]))
                        printf("%s%s%s", HIGHLIGHT, "Mark not set", NORMAL);
-       }
-       else
+       } else
                printf("%s%s%s", HIGHLIGHT, "Invalid mark letter", NORMAL);
 }
 #endif
 
 
-#ifdef CONFIG_FEATURE_LESS_BRACKETS
+#if ENABLE_FEATURE_LESS_BRACKETS
 
 static char opp_bracket(char bracket)
 {
@@ -977,8 +956,7 @@ static void match_left_bracket(char bracket)
                printf("%s%s%s", HIGHLIGHT, "No bracket in bottom line", NORMAL);
                printf("%s", flines[line_pos + height]);
                sleep(4);
-       }
-       else {
+       } else {
                for (i = line_pos + height - 2; i >= 0; i--) {
                        if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
                                bracket_line = i;
@@ -993,7 +971,7 @@ static void match_left_bracket(char bracket)
        }
 }
 
-#endif  /* CONFIG_FEATURE_LESS_BRACKETS */
+#endif  /* FEATURE_LESS_BRACKETS */
 
 static void keypress_process(int keypress)
 {
@@ -1031,7 +1009,7 @@ static void keypress_process(int keypress)
                case 'q': case 'Q':
                        tless_exit(0);
                        break;
-#ifdef CONFIG_FEATURE_LESS_MARKS
+#if ENABLE_FEATURE_LESS_MARKS
                case 'm':
                        add_mark();
                        buffer_print();
@@ -1048,21 +1026,20 @@ static void keypress_process(int keypress)
                        full_repaint();
                        break;
                case 's':
-                       if (flags & LESS_STATE_INP_STDIN)
-                               save_input_to_file();
+                       save_input_to_file();
                        break;
                case 'E':
                        examine_file();
                        break;
-#ifdef CONFIG_FEATURE_LESS_FLAGS
+#if ENABLE_FEATURE_LESS_FLAGS
                case '=':
                        clear_line();
                        m_status_print();
                        break;
 #endif
-#ifdef CONFIG_FEATURE_LESS_REGEXP
+#if ENABLE_FEATURE_LESS_REGEXP
                case '/':
-                       flags &= ~LESS_STATE_MATCH_BACKWARDS;
+                       option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
                        regex_process();
                        break;
                case 'n':
@@ -1072,11 +1049,11 @@ static void keypress_process(int keypress)
                        goto_match(match_pos - 1);
                        break;
                case '?':
-                       flags |= LESS_STATE_MATCH_BACKWARDS;
+                       option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
                        regex_process();
                        break;
 #endif
-#ifdef CONFIG_FEATURE_LESS_FLAGCS
+#if ENABLE_FEATURE_LESS_FLAGCS
                case '-':
                        flag_change();
                        buffer_print();
@@ -1085,7 +1062,7 @@ static void keypress_process(int keypress)
                        show_flag_status();
                        break;
 #endif
-#ifdef CONFIG_FEATURE_LESS_BRACKETS
+#if ENABLE_FEATURE_LESS_BRACKETS
                case '{': case '(': case '[':
                        match_right_bracket(keypress);
                        break;
@@ -1104,30 +1081,42 @@ static void keypress_process(int keypress)
                number_process(keypress);
 }
 
-int less_main(int argc, char **argv) {
+static void sig_catcher(int sig ATTRIBUTE_UNUSED)
+{
+       set_tty_cooked();
+       exit(1);
+}
 
+int less_main(int argc, char **argv)
+{
        int keypress;
 
-       flags = getopt32(argc, argv, "EMmN~");
-
+       getopt32(argc, argv, "EMmN~");
        argc -= optind;
        argv += optind;
        files = argv;
        num_files = argc;
 
        if (!num_files) {
-               if (ttyname(STDIN_FILENO) == NULL)
-                       flags |= LESS_STATE_INP_STDIN;
-               else {
+               if (isatty(STDIN_FILENO)) {
+                       /* Just "less"? No file and no redirection? */
                        bb_error_msg("missing filename");
                        bb_show_usage();
                }
-       }
+       } else
+               filename = xstrdup(files[0]);
+
+       /* FIXME: another popular pager, most, detects when stdout
+        * is not a tty and turns into cat */
+       inp = xfopen(CURRENT_TTY, "r");
 
-       strcpy(filename, (flags & LESS_STATE_INP_STDIN) ? bb_msg_standard_input : files[0]);
-       get_terminal_width_height(0, &width, &height);
+       get_terminal_width_height(fileno(inp), &width, &height);
        data_readlines();
+
+       signal(SIGTERM, sig_catcher);
+       signal(SIGINT, sig_catcher);
        tcgetattr(fileno(inp), &term_orig);
+
        term_vi = term_orig;
        term_vi.c_lflag &= (~ICANON & ~ECHO);
        term_vi.c_iflag &= (~IXON & ~ICRNL);