less: implement waiting for input using select(). Rather tricky business.
authorDenis Vlasenko <vda.linux@googlemail.com>
Sun, 24 Dec 2006 07:14:17 +0000 (07:14 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Sun, 24 Dec 2006 07:14:17 +0000 (07:14 -0000)
But we do not read entire input anymore up-front.

miscutils/less.c
shell/ash.c

index 03b93973f5c4ecea8b54592ebc9d6f6e37391ffb..66158899dc09449202469d65000d2f60c97b31b8 100644 (file)
 #include "xregex.h"
 #endif
 
-
-/* These are the escape sequences corresponding to special keys */
-#define REAL_KEY_UP 'A'
-#define REAL_KEY_DOWN 'B'
-#define REAL_KEY_RIGHT 'C'
-#define REAL_KEY_LEFT 'D'
-#define REAL_PAGE_UP '5'
-#define REAL_PAGE_DOWN '6'
-#define REAL_KEY_HOME '7'
-#define REAL_KEY_END '8'
-
-/* These are the special codes assigned by this program to the special keys */
-#define KEY_UP 20
-#define KEY_DOWN 21
-#define KEY_RIGHT 22
-#define KEY_LEFT 23
-#define PAGE_UP 24
-#define PAGE_DOWN 25
-#define KEY_HOME 26
-#define KEY_END 27
+/* FIXME: currently doesn't work right */
+#undef ENABLE_FEATURE_LESS_FLAGCS
+#define ENABLE_FEATURE_LESS_FLAGCS 0
 
 /* The escape codes for highlighted and normal text */
 #define HIGHLIGHT "\033[7m"
 /* The escape code to clear to end of line */
 #define CLEAR_2_EOL "\033[K"
 
-#define MAXLINES CONFIG_FEATURE_LESS_MAXLINES
+/* These are the escape sequences corresponding to special keys */
+enum {
+       REAL_KEY_UP = 'A',
+       REAL_KEY_DOWN = 'B',
+       REAL_KEY_RIGHT = 'C',
+       REAL_KEY_LEFT = 'D',
+       REAL_PAGE_UP = '5',
+       REAL_PAGE_DOWN = '6',
+       REAL_KEY_HOME = '7',
+       REAL_KEY_END = '8',
+
+/* These are the special codes assigned by this program to the special keys */
+       KEY_UP = 20,
+       KEY_DOWN = 21,
+       KEY_RIGHT = 22,
+       KEY_LEFT = 23,
+       PAGE_UP = 24,
+       PAGE_DOWN = 25,
+       KEY_HOME = 26,
+       KEY_END = 27,
+
+/* Absolute max of lines eaten */
+       MAXLINES = CONFIG_FEATURE_LESS_MAXLINES,
+
+/* This many "after the end" lines we will show (at max) */
+       TILDES = 1,
+};
+
+static unsigned max_displayed_line;
+static unsigned width;
+static const char *empty_line_marker = "~";
 
-static int height;
-static int width;
-static char **files;
 static char *filename;
+static char **files;
+static unsigned num_files = 1;
+static unsigned current_file = 1;
 static const char **buffer;
-static char **flines;
-static int current_file = 1;
-static int line_pos;
-static int num_flines;
-static int num_files = 1;
-static const char *empty_line_marker = "~";
+static const char **flines;
+static int cur_fline; /* signed */
+static unsigned max_fline;
+static unsigned max_lineno; /* this one tracks linewrap */
+
+static ssize_t eof_error = 1; /* eof if 0, error if < 0 */
+static char terminated = 1;
+static size_t readpos;
+static size_t readeof;
+/* last position in last line, taking into account tabs */
+static size_t linepos;
 
 /* Command line options */
-#define FLAG_E 1
-#define FLAG_M (1<<1)
-#define FLAG_m (1<<2)
-#define FLAG_N (1<<3)
-#define FLAG_TILDE (1<<4)
+enum {
+       FLAG_E = 1,
+       FLAG_M = 1 << 1,
+       FLAG_m = 1 << 2,
+       FLAG_N = 1 << 3,
+       FLAG_TILDE = 1 << 4,
 /* hijack command line options variable for internal state vars */
-#define LESS_STATE_MATCH_BACKWARDS (1<<6)
+       LESS_STATE_MATCH_BACKWARDS = 1 << 15,
+};
 
 #if ENABLE_FEATURE_LESS_MARKS
-static int mark_lines[15][2];
-static int num_marks;
+static unsigned mark_lines[15][2];
+static unsigned num_marks;
 #endif
 
 #if ENABLE_FEATURE_LESS_REGEXP
-static int *match_lines;
-static int match_pos;
-static int num_matches;
+static unsigned *match_lines;
+static int match_pos; /* signed! */
+static unsigned num_matches;
 static regex_t pattern;
-static int pattern_valid;
+static unsigned pattern_valid;
 #endif
 
-/* Needed termios structures */
 static struct termios term_orig, term_vi;
 
 /* File pointer to get input from */
-static FILE *inp;
+static int kbd_fd;
 
 /* Reset terminal input to normal */
 static void set_tty_cooked(void)
 {
        fflush(stdout);
-       tcsetattr(fileno(inp), TCSANOW, &term_orig);
+       tcsetattr(kbd_fd, TCSANOW, &term_orig);
 }
 
 /* Exit the program gracefully */
-static void tless_exit(int code)
+static void less_exit(int code)
 {
        /* TODO: We really should save the terminal state when we start,
-                and restore it when we exit. Less does this with the
-                "ti" and "te" termcap commands; can this be done with
-                only termios.h? */
+        * and restore it when we exit. Less does this with the
+        * "ti" and "te" termcap commands; can this be done with
+        * only termios.h? */
 
        putchar('\n');
        fflush_stdout_and_exit(code);
 }
 
-/* Grab a character from input without requiring the return key. If the
-   character is ASCII \033, get more characters and assign certain sequences
-   special return codes. Note that this function works best with raw input. */
-static int tless_getch(void)
-{
-       int input;
-       /* Set terminal input to raw mode (taken from vi.c) */
-       tcsetattr(fileno(inp), TCSANOW, &term_vi);
- again:
-       input = getc(inp);
-       /* Detect escape sequences (i.e. arrow keys) and handle
-          them accordingly */
-
-       if (input == '\033' && getc(inp) == '[') {
-               unsigned i;
-               input = getc(inp);
-               set_tty_cooked();
-
-               i = input - REAL_KEY_UP;
-               if (i < 4)
-                       return 20 + i;
-               i = input - REAL_PAGE_UP;
-               if (i < 4)
-                       return 24 + i;
-               return 0; /* ?? */
-       }
-       /* Reject almost all control chars */
-       if (input < ' ' && input != 0x0d && input != 8) goto again;
-       set_tty_cooked();
-       return input;
-}
-
-static char* tless_gets(int sz)
-{
-       int c;
-       int i = 0;
-       char *result = xzalloc(1);
-       while (1) {
-               c = tless_getch();
-               if (c == 0x0d)
-                       return result;
-               if (c == 0x7f) c = 8;
-               if (c == 8 && i) {
-                       printf("\x8 \x8");
-                       i--;
-               }
-               if (c < ' ')
-                       continue;
-               if (i >= width - sz - 1)
-                       continue; /* len limit */
-               putchar(c);
-               result[i++] = c;
-               result = xrealloc(result, i+1);
-               result[i] = '\0';
-       }
-}
-
 /* Move the cursor to a position (x,y), where (0,0) is the
    top-left corner of the console */
 static void move_cursor(int line, int row)
@@ -182,7 +144,7 @@ static void move_cursor(int line, int row)
 
 static void clear_line(void)
 {
-       printf("\033[%u;0H" CLEAR_2_EOL, height);
+       printf("\033[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
 }
 
 static void print_hilite(const char *str)
@@ -193,90 +155,116 @@ static void print_hilite(const char *str)
 static void print_statusline(const char *str)
 {
        clear_line();
-       printf(HIGHLIGHT"%.*s"NORMAL, width-1, str);
+       printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
 }
 
-static void data_readlines(void)
+static void read_lines(void)
 {
-       unsigned i, pos;
-       unsigned lineno = 1;
-       int w = width;
-       char terminated, last_terminated = 1;
-       char *current_line, *p;
-       FILE *fp;
+       /* TODO: regexp match array should be updated too */
 
-       if (filename)
-               fp = xfopen(filename, "r");
-       else {
-               /* "less" with no arguments in argv[] */
-               fp = stdin;
-               /* For status line only */
-               filename = xstrdup(bb_msg_standard_input);
-       }
+#define readbuf bb_common_bufsiz1
+       char *current_line, *p;
+       int w = width;
+       char last_terminated = terminated;
 
-       flines = NULL;
-       if (option_mask32 & FLAG_N) {
+       if (option_mask32 & FLAG_N)
                w -= 8;
+
+       current_line = xmalloc(w);
+       p = current_line;
+       max_fline += last_terminated;
+       if (!last_terminated) {
+               const char *cp = flines[max_fline];
+               if (option_mask32 & FLAG_N)
+                       cp += 8;
+               strcpy(current_line, cp);
+               p += strlen(current_line);
        }
-       for (i = 0; !feof(fp) && i <= MAXLINES; i++) {
-               flines = xrealloc(flines, (i+1) * sizeof(char *));
-               current_line = xmalloc(w);
+
+       while (1) {
  again:
-               p = current_line;
-               pos = 0;
+               *p = '\0';
                terminated = 0;
                while (1) {
-                       int c = getc(fp);
-                       if (c == '\t') pos += (pos^7) & 7;
-                       pos++;
-                       if (pos >= w) { ungetc(c, fp); break; }
-                       if (c == EOF) break;
+                       char c;
+                       if (readpos >= readeof) {
+ndelay_on(0);
+                               eof_error = safe_read(0, readbuf, sizeof(readbuf));
+ndelay_off(0);
+                               readpos = 0;
+                               readeof = eof_error;
+                               if (eof_error < 0) {
+                                       readeof = 0;
+                                       if (errno != EAGAIN)
+                                               print_statusline("read error");
+                               }
+                               if (eof_error <= 0) {
+                                       goto reached_eof;
+                               }
+                       }
+                       c = readbuf[readpos];
+                       if (c == '\t')
+                               linepos += (linepos^7) & 7;
+                       linepos++;
+                       if (linepos >= w)
+                               break;
+                       readpos++;
                        if (c == '\n') { terminated = 1; break; }
                        /* NUL is substituted by '\n'! */
                        if (c == '\0') c = '\n';
                        *p++ = c;
+                       *p = '\0';
                }
-               *p = '\0';
-               if (fp != stdin)
-                       die_if_ferror(fp, filename);
-
                /* Corner case: linewrap with only "" wrapping to next line */
                /* Looks ugly on screen, so we do not store this empty line */
                if (!last_terminated && !current_line[0]) {
                        last_terminated = 1;
-                       lineno++;
+                       max_lineno++;
                        goto again;
                }
-
+ reached_eof:
                last_terminated = terminated;
+               flines = xrealloc(flines, (max_fline+1) * sizeof(char *));
                if (option_mask32 & FLAG_N) {
                        /* Width of 7 preserves tab spacing in the text */
-                       flines[i] = xasprintf(
-                               (lineno <= 9999999) ? "%7u %s" : "%07u %s",
-                               lineno % 10000000, current_line);
+                       flines[max_fline] = xasprintf(
+                               (max_lineno <= 9999999) ? "%7u %s" : "%07u %s",
+                               max_lineno % 10000000, current_line);
                        free(current_line);
                        if (terminated)
-                               lineno++;
+                               max_lineno++;
                } else {
-                       flines[i] = xrealloc(current_line, strlen(current_line)+1);
+                       flines[max_fline] = xrealloc(current_line, strlen(current_line)+1);
                }
+               if (max_fline >= MAXLINES)
+                       break;
+               if (max_fline > cur_fline + max_displayed_line)
+                       break;
+               if (eof_error <= 0) {
+                       if (eof_error < 0 && errno == EAGAIN) {
+                               /* not yet eof or error, reset flag (or else
+                                * we will hog CPU - select() will return
+                                * immediately */
+                               eof_error = 1;
+                       }
+                       break;
+               }
+               max_fline++;
+               current_line = xmalloc(w);
+               p = current_line;
+               linepos = 0;
        }
-       num_flines = i - 1; /* buggie: 'num_flines' must be 'max_fline' */
-
-       /* Reset variables for a new file */
-
-       line_pos = 0;
-
-       fclose(fp);
+#undef readbuf
 }
 
 #if ENABLE_FEATURE_LESS_FLAGS
 
-/* Interestingly, writing calc_percent as a function and not a prototype saves around 32 bytes
+/* Interestingly, writing calc_percent as a function saves around 32 bytes
  * on my build. */
 static int calc_percent(void)
 {
-       return ((100 * (line_pos + height - 2) / num_flines) + 1);
+       unsigned p = 100 * (cur_fline + max_displayed_line) / (max_fline + 1);
+       return p <= 100 ? p : 100;
 }
 
 /* Print a status line if -M was specified */
@@ -289,16 +277,16 @@ static void m_status_print(void)
        if (num_files > 1)
                printf(" (file %i of %i)", current_file, num_files);
        printf(" lines %i-%i/%i ",
-                       line_pos + 1, line_pos + height - 1,
-                       num_flines + 1);
-       if (line_pos >= num_flines - height + 2) {
+                       cur_fline + 1, cur_fline + max_displayed_line + 1,
+                       max_fline + 1);
+       if (cur_fline >= max_fline - max_displayed_line) {
                printf("(END)"NORMAL);
                if (num_files > 1 && current_file != num_files)
-                       printf(HIGHLIGHT" - next: %s "NORMAL, files[current_file]);
+                       printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]);
                return;
        }
        percentage = calc_percent();
-       printf("%i%% "NORMAL, percentage);
+       printf("%i%%"NORMAL, percentage);
 }
 
 #endif
@@ -318,15 +306,15 @@ static void status_print(void)
 #endif
 
        clear_line();
-       if (line_pos && line_pos < num_flines - height + 2) {
+       if (cur_fline && cur_fline < max_fline - max_displayed_line) {
                putchar(':');
                return;
        }
        p = "(END)";
-       if (!line_pos)
+       if (!cur_fline)
                p = filename;
        if (num_files > 1) {
-               printf(HIGHLIGHT"%s (file %i of %i) "NORMAL,
+               printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
                                p, current_file, num_files);
                return;
        }
@@ -423,7 +411,7 @@ static void print_ascii(const char *str)
                do {
                        if (*str == 0x7f)
                                *p++ = '?';
-                       else if (*str == 0x9b)
+                       else if (*str == (char)0x9b)
                        /* VT100's CSI, aka Meta-ESC. Who's inventor? */
                        /* I want to know who committed this sin */
                                *p++ = '{';
@@ -443,7 +431,7 @@ static void buffer_print(void)
        int i;
 
        move_cursor(0, 0);
-       for (i = 0; i < height - 1; i++)
+       for (i = 0; i <= max_displayed_line; i++)
                if (pattern_valid)
                        print_found(buffer[i]);
                else
@@ -451,111 +439,194 @@ static void buffer_print(void)
        status_print();
 }
 
-/* Initialise the buffer */
-static void buffer_init(void)
+static void buffer_fill_and_print(void)
 {
        int i;
-
-       /* 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] = flines[i];
+       for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
+               buffer[i] = flines[cur_fline + i];
        }
-
-       /* If the buffer still isn't full, fill it with blank lines */
-       for (; i < height - 1; i++) {
+       for (; i <= max_displayed_line; i++) {
                buffer[i] = empty_line_marker;
        }
+       buffer_print();
 }
 
 /* Move the buffer up and down in the file in order to scroll */
 static void buffer_down(int nlines)
 {
-       int i;
+       int diff;
+       cur_fline += nlines;
+       read_lines();
 
-       if (line_pos + (height - 3) + nlines < num_flines) {
-               line_pos += nlines;
-               for (i = 0; i < (height - 1); i++) {
-                       buffer[i] = flines[line_pos + i];
-               }
-       } else {
+       if (cur_fline + max_displayed_line > max_fline + TILDES) {
+               cur_fline -= nlines;
+               diff = max_fline - (cur_fline + max_displayed_line) + TILDES;
                /* 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++) {
-                               buffer[i] = flines[line_pos + i];
-                       }
-               }
+               if (diff > 0)
+                       cur_fline += diff;
        }
-
-       /* We exit if the -E flag has been set */
-       if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines))
-               tless_exit(0);
+       buffer_fill_and_print();
 }
 
 static void buffer_up(int nlines)
 {
-       int i;
+       cur_fline -= nlines;
+       if (cur_fline < 0) cur_fline = 0;
+       read_lines();
+       buffer_fill_and_print();
+}
 
-       line_pos -= nlines;
-       if (line_pos < 0) line_pos = 0;
-       for (i = 0; i < height - 1; i++) {
-               if (line_pos + i <= num_flines) {
-                       buffer[i] = flines[line_pos + i];
-               } else {
-                       buffer[i] = empty_line_marker;
-               }
+static void buffer_line(int linenum)
+{
+       if (linenum + max_displayed_line > max_fline)
+               linenum = max_fline - max_displayed_line + TILDES;
+       if (linenum < 0) linenum = 0;
+       cur_fline = linenum;
+       buffer_fill_and_print();
+}
+
+static void open_file_and_read_lines(void)
+{
+       if (filename) {
+               int fd = xopen(filename, O_RDONLY);
+               dup2(fd, 0);
+               if (fd) close(fd);
+       } else {
+               /* "less" with no arguments in argv[] */
+               /* For status line only */
+               filename = xstrdup(bb_msg_standard_input);
        }
+       readpos = 0;
+       readeof = 0;
+       linepos = 0;
+       terminated = 1;
+       read_lines();
 }
 
-static void buffer_line(int linenum)
+/* Reinitialize everything for a new file - free the memory and start over */
+static void reinitialize(void)
 {
        int i;
 
-       if (linenum < 0 || linenum > num_flines) {
-               clear_line();
-               printf(HIGHLIGHT"%s%u"NORMAL, "Cannot seek to line ", linenum + 1);
-               return;
+       if (flines) {
+               for (i = 0; i <= max_fline; i++)
+                       free((void*)(flines[i]));
+               free(flines);
+               flines = NULL;
        }
 
-       for (i = 0; i < height - 1; i++) {
-               if (linenum + i <= num_flines)
-                       buffer[i] = flines[linenum + i];
-               else {
-                       buffer[i] = empty_line_marker;
-               }
+       max_fline = -1;
+       cur_fline = 0;
+       max_lineno = 0;
+       open_file_and_read_lines();
+       buffer_fill_and_print();
+}
+
+static char* getch_nowait(void)
+{
+       static char input[16];
+       ssize_t sz;
+       fd_set readfds;
+ again:
+       fflush(stdout);
+       FD_ZERO(&readfds);
+       if (max_fline <= cur_fline + max_displayed_line && eof_error > 0) {
+               /* We are interested in stdin */
+               FD_SET(0, &readfds);
        }
-       line_pos = linenum;
-       buffer_print();
+       FD_SET(kbd_fd, &readfds);
+       tcsetattr(kbd_fd, TCSANOW, &term_vi);
+       select(kbd_fd + 1, &readfds, NULL, NULL, NULL);
+
+       input[0] = '\0';
+       ndelay_on(kbd_fd);
+       sz = read(kbd_fd, input, sizeof(input));
+       ndelay_off(kbd_fd);
+       if (sz < 0) {
+               /* No keyboard input, but we have input on stdin! */
+               if (errno != EAGAIN) /* Huh?? */
+                       return input;
+               read_lines();
+               buffer_fill_and_print();
+               goto again;
+       }
+       return input;
 }
 
-/* Reinitialise everything for a new file - free the memory and start over */
-static void reinitialise(void)
+/* Grab a character from input without requiring the return key. If the
+   character is ASCII \033, get more characters and assign certain sequences
+   special return codes. Note that this function works best with raw input. */
+static int less_getch(void)
 {
-       int i;
+       char *input;
+       unsigned i;
+ again:
+       input = getch_nowait();
+       /* Detect escape sequences (i.e. arrow keys) and handle
+        * them accordingly */
 
-       for (i = 0; i <= num_flines; i++)
-               free(flines[i]);
-       free(flines);
+       if (input[0] == '\033' && input[1] == '[') {
+               set_tty_cooked();
+               i = input[2] - REAL_KEY_UP;
+               if (i < 4)
+                       return 20 + i;
+               i = input[2] - REAL_PAGE_UP;
+               if (i < 4)
+                       return 24 + i;
+               return 0;
+       }
+       /* Reject almost all control chars */
+       i = input[0];
+       if (i < ' ' && i != 0x0d && i != 8) goto again;
+       set_tty_cooked();
+       return i;
+}
 
-       data_readlines();
-       buffer_init();
-       buffer_print();
+static char* less_gets(int sz)
+{
+       char c;
+       int i = 0;
+       char *result = xzalloc(1);
+       while (1) {
+               fflush(stdout);
+
+               /* I be damned if I know why is it needed *repeatedly*,
+                * but it is needed. Is it because of stdio? */
+               tcsetattr(kbd_fd, TCSANOW, &term_vi);
+
+               read(kbd_fd, &c, 1);
+               if (c == 0x0d)
+                       return result;
+               if (c == 0x7f)
+                       c = 8;
+               if (c == 8 && i) {
+                       printf("\x8 \x8");
+                       i--;
+               }
+               if (c < ' ')
+                       continue;
+               if (i >= width - sz - 1)
+                       continue; /* len limit */
+               putchar(c);
+               result[i++] = c;
+               result = xrealloc(result, i+1);
+               result[i] = '\0';
+       }
 }
 
 static void examine_file(void)
 {
        print_statusline("Examine: ");
        free(filename);
-       filename = tless_gets(sizeof("Examine: ")-1);
+       filename = less_gets(sizeof("Examine: ")-1);
        /* files start by = argv. why we assume that argv is infinitely long??
        files[num_files] = filename;
        current_file = num_files + 1;
        num_files++; */
        files[0] = filename;
        num_files = current_file = 1;
-       reinitialise();
+       reinitialize();
 }
 
 /* This function changes the file currently being paged. direction can be one of the following:
@@ -569,7 +640,7 @@ static void change_file(int direction)
                current_file = direction ? current_file + direction : 1;
                free(filename);
                filename = xstrdup(files[current_file - 1]);
-               reinitialise();
+               reinitialize();
        } else {
                print_statusline(direction > 0 ? "No next file" : "No previous file");
        }
@@ -579,19 +650,20 @@ static void remove_current_file(void)
 {
        int i;
 
+       if (num_files < 2)
+               return;
+
        if (current_file != 1) {
                change_file(-1);
                for (i = 3; i <= num_files; i++)
                        files[i - 2] = files[i - 1];
                num_files--;
-               buffer_print();
        } else {
                change_file(1);
                for (i = 2; i <= num_files; i++)
                        files[i - 2] = files[i - 1];
                num_files--;
                current_file--;
-               buffer_print();
        }
 }
 
@@ -602,33 +674,31 @@ static void colon_process(void)
        /* Clear the current line and print a prompt */
        print_statusline(" :");
 
-       keypress = tless_getch();
+       keypress = less_getch();
        switch (keypress) {
-               case 'd':
-                       remove_current_file();
-                       break;
-               case 'e':
-                       examine_file();
-                       break;
+       case 'd':
+               remove_current_file();
+               break;
+       case 'e':
+               examine_file();
+               break;
 #if ENABLE_FEATURE_LESS_FLAGS
-               case 'f':
-                       m_status_print();
-                       break;
+       case 'f':
+               m_status_print();
+               break;
 #endif
-               case 'n':
-                       change_file(1);
-                       break;
-               case 'p':
-                       change_file(-1);
-                       break;
-               case 'q':
-                       tless_exit(0);
-                       break;
-               case 'x':
-                       change_file(0);
-                       break;
-               default:
-                       break;
+       case 'n':
+               change_file(1);
+               break;
+       case 'p':
+               change_file(-1);
+               break;
+       case 'q':
+               less_exit(0);
+               break;
+       case 'x':
+               change_file(0);
+               break;
        }
 }
 
@@ -638,7 +708,7 @@ static int normalize_match_pos(int match)
        if (match >= num_matches)
                match_pos = num_matches - 1;
        if (match < 0)
-               return (match_pos = 0);
+               match_pos = 0;
        return match_pos;
 }
 
@@ -654,8 +724,8 @@ static void regex_process(void)
        char *uncomp_regex, *err;
 
        /* Reset variables */
-       match_lines = xrealloc(match_lines, sizeof(int));
-       match_lines[0] = -1;
+       free(match_lines);
+       match_lines = NULL;
        match_pos = 0;
        num_matches = 0;
        if (pattern_valid) {
@@ -666,8 +736,8 @@ static void regex_process(void)
        /* Get the uncompiled regular expression from the user */
        clear_line();
        putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
-       uncomp_regex = tless_gets(1);
-       if (/*!uncomp_regex ||*/ !uncomp_regex[0]) {
+       uncomp_regex = less_gets(1);
+       if (!uncomp_regex[0]) {
                free(uncomp_regex);
                buffer_print();
                return;
@@ -684,19 +754,19 @@ static void regex_process(void)
        pattern_valid = 1;
 
        /* Run the regex on each line of the current file */
-       for (match_pos = 0; match_pos <= num_flines; match_pos++) {
+       for (match_pos = 0; match_pos <= max_fline; match_pos++) {
                if (regexec(&pattern, flines[match_pos], 0, NULL, 0) == 0) {
                        match_lines = xrealloc(match_lines, (num_matches+1) * sizeof(int));
                        match_lines[num_matches++] = match_pos;
                }
        }
 
-       if (num_matches == 0 || num_flines <= height - 2) {
+       if (num_matches == 0 || max_fline <= max_displayed_line) {
                buffer_print();
                return;
        }
        for (match_pos = 0; match_pos < num_matches; match_pos++) {
-               if (match_lines[match_pos] > line_pos)
+               if (match_lines[match_pos] > cur_fline)
                        break;
        }
        if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) match_pos--;
@@ -719,7 +789,7 @@ static void number_process(int first_digit)
 
        /* Receive input until a letter is given */
        while (i < sizeof(num_input)-1) {
-               num_input[i] = tless_getch();
+               num_input[i] = less_getch();
                if (!num_input[i] || !isdigit(num_input[i]))
                        break;
                putchar(num_input[i]);
@@ -738,34 +808,38 @@ static void number_process(int first_digit)
 
        /* We now know the number and the letter entered, so we process them */
        switch (keypress) {
-               case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
-                       buffer_down(num);
-                       break;
-               case KEY_UP: case 'b': case 'w': case 'y': case 'u':
-                       buffer_up(num);
-                       break;
-               case 'g': case '<': case 'G': case '>':
-                       if (num_flines >= height - 2)
-                               buffer_line(num - 1);
-                       break;
-               case 'p': case '%':
-                       buffer_line(((num / 100) * num_flines) - 1);
-                       break;
+       case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
+               buffer_down(num);
+               buffer_print();
+               break;
+       case KEY_UP: case 'b': case 'w': case 'y': case 'u':
+               buffer_up(num);
+               buffer_print();
+               break;
+       case 'g': case '<': case 'G': case '>':
+               cur_fline = num + max_displayed_line;
+               read_lines();
+               buffer_line(num - 1);
+               break;
+       case 'p': case '%':
+               num = num * (max_fline / 100); /* + max_fline / 2; */
+               cur_fline = num + max_displayed_line;
+               read_lines();
+               buffer_line(num);
+               break;
 #if ENABLE_FEATURE_LESS_REGEXP
-               case 'n':
-                       goto_match(match_pos + num);
-                       break;
-               case '/':
-                       option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
-                       regex_process();
-                       break;
-               case '?':
-                       option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
-                       regex_process();
-                       break;
+       case 'n':
+               goto_match(match_pos + num);
+               break;
+       case '/':
+               option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
+               regex_process();
+               break;
+       case '?':
+               option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
+               regex_process();
+               break;
 #endif
-               default:
-                       break;
        }
 }
 
@@ -776,23 +850,21 @@ static void flag_change(void)
 
        clear_line();
        putchar('-');
-       keypress = tless_getch();
+       keypress = less_getch();
 
        switch (keypress) {
-               case 'M':
-                       option_mask32 ^= FLAG_M;
-                       break;
-               case 'm':
-                       option_mask32 ^= FLAG_m;
-                       break;
-               case 'E':
-                       option_mask32 ^= FLAG_E;
-                       break;
-               case '~':
-                       option_mask32 ^= FLAG_TILDE;
-                       break;
-               default:
-                       break;
+       case 'M':
+               option_mask32 ^= FLAG_M;
+               break;
+       case 'm':
+               option_mask32 ^= FLAG_m;
+               break;
+       case 'E':
+               option_mask32 ^= FLAG_E;
+               break;
+       case '~':
+               option_mask32 ^= FLAG_TILDE;
+               break;
        }
 }
 
@@ -803,27 +875,27 @@ static void show_flag_status(void)
 
        clear_line();
        putchar('_');
-       keypress = tless_getch();
+       keypress = less_getch();
 
        switch (keypress) {
-               case 'M':
-                       flag_val = option_mask32 & FLAG_M;
-                       break;
-               case 'm':
-                       flag_val = option_mask32 & FLAG_m;
-                       break;
-               case '~':
-                       flag_val = option_mask32 & FLAG_TILDE;
-                       break;
-               case 'N':
-                       flag_val = option_mask32 & FLAG_N;
-                       break;
-               case 'E':
-                       flag_val = option_mask32 & FLAG_E;
-                       break;
-               default:
-                       flag_val = 0;
-                       break;
+       case 'M':
+               flag_val = option_mask32 & FLAG_M;
+               break;
+       case 'm':
+               flag_val = option_mask32 & FLAG_m;
+               break;
+       case '~':
+               flag_val = option_mask32 & FLAG_TILDE;
+               break;
+       case 'N':
+               flag_val = option_mask32 & FLAG_N;
+               break;
+       case 'E':
+               flag_val = option_mask32 & FLAG_E;
+               break;
+       default:
+               flag_val = 0;
+               break;
        }
 
        clear_line();
@@ -831,15 +903,6 @@ static void show_flag_status(void)
 }
 #endif
 
-static void full_repaint(void)
-{
-       int temp_line_pos = line_pos;
-       data_readlines();
-       buffer_init();
-       buffer_line(temp_line_pos);
-}
-
-
 static void save_input_to_file(void)
 {
        char *current_line;
@@ -847,7 +910,7 @@ static void save_input_to_file(void)
        FILE *fp;
 
        print_statusline("Log file: ");
-       current_line = tless_gets(sizeof("Log file: ")-1);
+       current_line = less_gets(sizeof("Log file: ")-1);
        if (strlen(current_line) > 0) {
                fp = fopen(current_line, "w");
                free(current_line);
@@ -855,7 +918,7 @@ static void save_input_to_file(void)
                        print_statusline("Error opening log file");
                        return;
                }
-               for (i = 0; i < num_flines; i++)
+               for (i = 0; i < max_fline; i++)
                        fprintf(fp, "%s\n", flines[i]);
                fclose(fp);
                buffer_print();
@@ -871,16 +934,15 @@ static void add_mark(void)
        int letter;
 
        print_statusline("Mark: ");
-       letter = tless_getch();
+       letter = less_getch();
 
        if (isalpha(letter)) {
-
                /* If we exceed 15 marks, start overwriting previous ones */
                if (num_marks == 14)
                        num_marks = 0;
 
                mark_lines[num_marks][0] = letter;
-               mark_lines[num_marks][1] = line_pos;
+               mark_lines[num_marks][1] = cur_fline;
                num_marks++;
        } else {
                print_statusline("Invalid mark letter");
@@ -893,7 +955,7 @@ static void goto_mark(void)
        int i;
 
        print_statusline("Go to mark: ");
-       letter = tless_getch();
+       letter = less_getch();
        clear_line();
 
        if (isalpha(letter)) {
@@ -915,17 +977,16 @@ static void goto_mark(void)
 static char opp_bracket(char bracket)
 {
        switch (bracket) {
-               case '{': case '[':
-                       return bracket + 2;
-               case '(':
-                       return ')';
-               case '}': case ']':
-                       return bracket - 2;
-               case ')':
-                       return '(';
-               default:
-                       return 0;
+       case '{': case '[':
+               return bracket + 2;
+       case '(':
+               return ')';
+       case '}': case ']':
+               return bracket - 2;
+       case ')':
+               return '(';
        }
+       return 0;
 }
 
 static void match_right_bracket(char bracket)
@@ -933,11 +994,11 @@ static void match_right_bracket(char bracket)
        int bracket_line = -1;
        int i;
 
-       if (strchr(flines[line_pos], bracket) == NULL) {
+       if (strchr(flines[cur_fline], bracket) == NULL) {
                print_statusline("No bracket in top line");
                return;
        }
-       for (i = line_pos + 1; i < num_flines; i++) {
+       for (i = cur_fline + 1; i < max_fline; i++) {
                if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
                        bracket_line = i;
                        break;
@@ -945,7 +1006,7 @@ static void match_right_bracket(char bracket)
        }
        if (bracket_line == -1)
                print_statusline("No matching bracket found");
-       buffer_line(bracket_line - height + 2);
+       buffer_line(bracket_line - max_displayed_line);
 }
 
 static void match_left_bracket(char bracket)
@@ -953,12 +1014,12 @@ static void match_left_bracket(char bracket)
        int bracket_line = -1;
        int i;
 
-       if (strchr(flines[line_pos + height - 2], bracket) == NULL) {
+       if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) {
                print_statusline("No bracket in bottom line");
                return;
        }
 
-       for (i = line_pos + height - 2; i >= 0; i--) {
+       for (i = cur_fline + max_displayed_line; i >= 0; i--) {
                if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
                        bracket_line = i;
                        break;
@@ -974,105 +1035,104 @@ static void match_left_bracket(char bracket)
 static void keypress_process(int keypress)
 {
        switch (keypress) {
-               case KEY_DOWN: case 'e': case 'j': case 0x0d:
-                       buffer_down(1);
-                       buffer_print();
-                       break;
-               case KEY_UP: case 'y': case 'k':
-                       buffer_up(1);
-                       buffer_print();
-                       break;
-               case PAGE_DOWN: case ' ': case 'z':
-                       buffer_down(height - 1);
-                       buffer_print();
-                       break;
-               case PAGE_UP: case 'w': case 'b':
-                       buffer_up(height - 1);
-                       buffer_print();
-                       break;
-               case 'd':
-                       buffer_down((height - 1) / 2);
-                       buffer_print();
-                       break;
-               case 'u':
-                       buffer_up((height - 1) / 2);
-                       buffer_print();
-                       break;
-               case KEY_HOME: case 'g': case 'p': case '<': case '%':
-                       buffer_line(0);
-                       break;
-               case KEY_END: case 'G': case '>':
-                       buffer_line(num_flines - height + 2);
-                       break;
-               case 'q': case 'Q':
-                       tless_exit(0);
-                       break;
+       case KEY_DOWN: case 'e': case 'j': case 0x0d:
+               buffer_down(1);
+               buffer_print();
+               break;
+       case KEY_UP: case 'y': case 'k':
+               buffer_up(1);
+               buffer_print();
+               break;
+       case PAGE_DOWN: case ' ': case 'z':
+               buffer_down(max_displayed_line + 1);
+               buffer_print();
+               break;
+       case PAGE_UP: case 'w': case 'b':
+               buffer_up(max_displayed_line + 1);
+               buffer_print();
+               break;
+       case 'd':
+               buffer_down((max_displayed_line + 1) / 2);
+               buffer_print();
+               break;
+       case 'u':
+               buffer_up((max_displayed_line + 1) / 2);
+               buffer_print();
+               break;
+       case KEY_HOME: case 'g': case 'p': case '<': case '%':
+               buffer_line(0);
+               break;
+       case KEY_END: case 'G': case '>':
+               cur_fline = MAXLINES;
+               read_lines();
+               buffer_line(cur_fline);
+               break;
+       case 'q': case 'Q':
+               less_exit(0);
+               break;
 #if ENABLE_FEATURE_LESS_MARKS
-               case 'm':
-                       add_mark();
-                       buffer_print();
-                       break;
-               case '\'':
-                       goto_mark();
-                       buffer_print();
-                       break;
+       case 'm':
+               add_mark();
+               buffer_print();
+               break;
+       case '\'':
+               goto_mark();
+               buffer_print();
+               break;
 #endif
-               case 'r':
-                       buffer_print();
-                       break;
-               case 'R':
-                       full_repaint();
-                       break;
-               case 's':
-                       save_input_to_file();
-                       break;
-               case 'E':
-                       examine_file();
-                       break;
+       case 'r': case 'R':
+               buffer_print();
+               break;
+       /*case 'R':
+               full_repaint();
+               break;*/
+       case 's':
+               save_input_to_file();
+               break;
+       case 'E':
+               examine_file();
+               break;
 #if ENABLE_FEATURE_LESS_FLAGS
-               case '=':
-                       m_status_print();
-                       break;
+       case '=':
+               m_status_print();
+               break;
 #endif
 #if ENABLE_FEATURE_LESS_REGEXP
-               case '/':
-                       option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
-                       regex_process();
-                       break;
-               case 'n':
-//printf("HERE 3\n");sleep(1);
-                       goto_match(match_pos + 1);
-                       break;
-               case 'N':
-                       goto_match(match_pos - 1);
-                       break;
-               case '?':
-                       option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
-                       regex_process();
-                       break;
+       case '/':
+               option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
+               regex_process();
+               break;
+       case 'n':
+               goto_match(match_pos + 1);
+               break;
+       case 'N':
+               goto_match(match_pos - 1);
+               break;
+       case '?':
+               option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
+               regex_process();
+               break;
 #endif
 #if ENABLE_FEATURE_LESS_FLAGCS
-               case '-':
-                       flag_change();
-                       buffer_print();
-                       break;
-               case '_':
-                       show_flag_status();
-                       break;
+       case '-':
+               flag_change();
+               buffer_print();
+               break;
+       case '_':
+               show_flag_status();
+               break;
 #endif
 #if ENABLE_FEATURE_LESS_BRACKETS
-               case '{': case '(': case '[':
-                       match_right_bracket(keypress);
-                       break;
-               case '}': case ')': case ']':
-                       match_left_bracket(keypress);
-                       break;
+       case '{': case '(': case '[':
+               match_right_bracket(keypress);
+               break;
+       case '}': case ')': case ']':
+               match_left_bracket(keypress);
+               break;
 #endif
-               case ':':
-                       colon_process();
-                       break;
-               default:
-                       break;
+       case ':':
+               colon_process();
+               break;
        }
 
        if (isdigit(keypress))
@@ -1092,8 +1152,8 @@ int less_main(int argc, char **argv)
        getopt32(argc, argv, "EMmN~");
        argc -= optind;
        argv += optind;
-       files = argv;
        num_files = argc;
+       files = argv;
 
        /* Another popular pager, most, detects when stdout
         * is not a tty and turns into cat. This makes sense. */
@@ -1109,33 +1169,35 @@ int less_main(int argc, char **argv)
        } else
                filename = xstrdup(files[0]);
 
-       inp = xfopen(CURRENT_TTY, "r");
+       kbd_fd = xopen(CURRENT_TTY, O_RDONLY);
 
-       get_terminal_width_height(fileno(inp), &width, &height);
-       if (width < 10 || height < 3)
+       get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
+       /* 20: two tabstops + 4 */
+       if (width < 20 || max_displayed_line < 3)
                bb_error_msg_and_die("too narrow here");
+       max_displayed_line -= 2;
 
-       buffer = xmalloc(height * sizeof(char *));
+       buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
        if (option_mask32 & FLAG_TILDE)
                empty_line_marker = "";
 
-       data_readlines();
-
-       tcgetattr(fileno(inp), &term_orig);
+       tcgetattr(kbd_fd, &term_orig);
        signal(SIGTERM, sig_catcher);
        signal(SIGINT, sig_catcher);
        term_vi = term_orig;
-       term_vi.c_lflag &= (~ICANON & ~ECHO);
-       term_vi.c_iflag &= (~IXON & ~ICRNL);
-       term_vi.c_oflag &= (~ONLCR);
+       term_vi.c_lflag &= ~(ICANON | ECHO);
+       term_vi.c_iflag &= ~(IXON | ICRNL);
+       /*term_vi.c_oflag &= ~ONLCR;*/
        term_vi.c_cc[VMIN] = 1;
        term_vi.c_cc[VTIME] = 0;
 
-       buffer_init();
-       buffer_print();
+       /* Want to do it just once, but it doesn't work, */
+       /* so we are redoing it (see code above). Mystery... */
+       /*tcsetattr(kbd_fd, TCSANOW, &term_vi);*/
 
+       reinitialize();
        while (1) {
-               keypress = tless_getch();
+               keypress = less_getch();
                keypress_process(keypress);
        }
 }
index 591e0a658e3b0252d464a1a87178df2c654e0693..2de61dad926b1eaa1e5252c126873fd2737d7d89 100644 (file)
@@ -12693,7 +12693,7 @@ readcmd(int argc, char **argv)
                FD_ZERO (&set);
                FD_SET (0, &set);
 
-               i = select (FD_SETSIZE, &set, NULL, NULL, &ts);
+               i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
                if (!i) {
 #if defined(CONFIG_ASH_READ_NCHARS)
                        if (nch_flag)