diff options
Diffstat (limited to 'miscutils')
| -rw-r--r-- | miscutils/less.c | 484 |
1 files changed, 236 insertions, 248 deletions
diff --git a/miscutils/less.c b/miscutils/less.c index 7350067..6843ddd 100644 --- a/miscutils/less.c +++ b/miscutils/less.c @@ -8,30 +8,20 @@ */ /* - * This program needs a lot of development, so consider it in a beta stage - * at best. + * TODO: + * - Add more regular expression support - search modifiers, certain matches, etc. + * - Add more complex bracket searching - currently, nested brackets are + * not considered. + * - Add support for "F" as an input. This causes less to act in + * a similar way to tail -f. + * - Allow horizontal scrolling. * - * TODO: - * - Add more regular expression support - search modifiers, certain matches, etc. - * - Add more complex bracket searching - currently, nested brackets are - * not considered. - * - Add support for "F" as an input. This causes less to act in - * a similar way to tail -f. - * - Check for binary files, and prompt the user if a binary file - * is detected. - * - Allow horizontal scrolling. Currently, lines simply continue onto - * the next line, per the terminal's discretion - * - * Notes: - * - filename is an array and not a pointer because that avoids all sorts - * of complications involving the fact that something that is pointed to - * will be changed if the pointer is changed. - * - the inp file pointer is used so that keyboard input works after - * redirected input has been read from stdin -*/ + * Notes: + * - the inp file pointer is used so that keyboard input works after + * redirected input has been read from stdin + */ #include "busybox.h" - #if ENABLE_FEATURE_LESS_REGEXP #include "xregex.h" #endif @@ -70,12 +60,13 @@ static int height; static int width; static char **files; static char *filename; -static char **buffer; +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 = "~"; /* Command line options */ #define FLAG_E 1 @@ -84,7 +75,6 @@ static int num_files = 1; #define FLAG_N (1<<3) #define FLAG_TILDE (1<<4) /* hijack command line options variable for internal state vars */ -#define LESS_STATE_PAST_EOF (1<<5) #define LESS_STATE_MATCH_BACKWARDS (1<<6) #if ENABLE_FEATURE_LESS_MARKS @@ -93,11 +83,11 @@ static int num_marks; #endif #if ENABLE_FEATURE_LESS_REGEXP -static int match_found; static int *match_lines; static int match_pos; static int num_matches; -static regex_t old_pattern; +static regex_t pattern; +static int pattern_valid; #endif /* Needed termios structures */ @@ -174,52 +164,57 @@ static void data_readlines(void) unsigned i; unsigned n = 1; int w = width; - char *last_nl = (char*)1; /* "not NULL" */ - char *current_line; + /* "remained unused space" in a line (0 if line fills entire width) */ + int rem, last_rem = 1; /* "not 0" */ + char *current_line, *p; FILE *fp; fp = filename ? xfopen(filename, "r") : stdin; flines = NULL; 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); + p = current_line; + rem = w - 1; + do { + int c = getc(fp); + if (c == EOF) break; + if (c == '\n') break; + /* NUL is substituted by '\n'! */ + if (c == '\0') c = '\n'; + *p++ = c; + } while (--rem); + *p = '\0'; if (fp != stdin) die_if_ferror(fp, filename); - /* 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" */ + /* Corner case: linewrap with only "" wrapping to next line */ + /* Looks ugly on screen, so we do not store this empty line */ + if (!last_rem && !current_line[0]) { + last_rem = 1; /* "not 0" */ n++; goto again; } - last_nl = last_char_is(current_line, '\n'); - if (last_nl) - *last_nl = '\0'; + last_rem = rem; if (option_mask32 & FLAG_N) { flines[i] = xasprintf((n <= 99999) ? "%5u %s" : "%05u %s", n % 100000, current_line); free(current_line); - if (last_nl) + if (rem) n++; } else { flines[i] = xrealloc(current_line, strlen(current_line)+1); } } - num_flines = i - 2; + num_flines = i - 1; /* buggie: 'num_flines' must be 'max_fline' */ /* Reset variables for a new file */ line_pos = 0; - option_mask32 &= ~LESS_STATE_PAST_EOF; fclose(fp); } @@ -238,36 +233,28 @@ static void m_status_print(void) { int percentage; - if (!(option_mask32 & LESS_STATE_PAST_EOF)) { - if (!line_pos) { - 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 { - printf("%s%s lines %i-%i/%i ", HIGHLIGHT, - filename, line_pos + 1, line_pos + height - 1, - num_flines + 1); - } - } else { - printf("%s %s lines %i-%i/%i ", HIGHLIGHT, filename, + if (!line_pos) { + 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); - } - - if (line_pos == num_flines - height + 2) { - printf("(END) %s", NORMAL); - if ((num_files > 1) && (current_file != num_files)) - printf("%s- Next: %s%s", HIGHLIGHT, files[current_file], NORMAL); } else { - percentage = calc_percent(); - printf("%i%% %s", percentage, NORMAL); + printf("%s%s lines %i-%i/%i ", HIGHLIGHT, + filename, line_pos + 1, line_pos + height - 1, + num_flines + 1); } } else { - printf("%s%s lines %i-%i/%i (END) ", HIGHLIGHT, filename, - line_pos + 1, num_flines + 1, num_flines + 1); + printf("%s %s lines %i-%i/%i ", HIGHLIGHT, filename, + line_pos + 1, line_pos + height - 1, num_flines + 1); + } + + if (line_pos >= num_flines - height + 2) { + printf("(END) %s", NORMAL); if ((num_files > 1) && (current_file != num_files)) - printf("- Next: %s", files[current_file]); - printf("%s", NORMAL); + printf("%s- Next: %s%s", HIGHLIGHT, files[current_file], NORMAL); + } else { + percentage = calc_percent(); + printf("%i%% %s", percentage, NORMAL); } } @@ -315,22 +302,123 @@ static void status_print(void) #endif } +static char controls[] = + /**/"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" + "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" + "\x7f\x9b"; /* DEL and infamous Meta-ESC :( */ +static char ctrlconv[] = + /* Note that on input NUL is converted to '\n' ('\x0a') */ + /* Therefore we subst '\n' with '@', not 'J' */ + "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f" + "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f"; + +static void print_found(const char *line) +{ + int match_status; + int eflags; + char *growline; + regmatch_t match_structs; + + char buf[width]; + const char *str = line; + char *p = buf; + size_t n; + + while (*str) { + n = strcspn(str, controls); + if (n) { + if (!str[n]) break; + memcpy(p, str, n); + p += n; + str += n; + } + n = strspn(str, controls); + memset(p, '.', n); + p += n; + str += n; + /* + do { + if (*str == '\x7f') { *p++ = '?'; str++; } + else if (*str == '\x9b') { *p++ = '{'; str++; } + else *p++ = ctrlconv[(unsigned char)*str++]; + } while (--n); + */ + } + strcpy(p, str); + + /* buf[] holds quarantined version of str */ + + /* Each part of the line that matches has the HIGHLIGHT + and NORMAL escape sequences placed around it. + NB: we regex against line, but insert text + from quarantined copy (buf[]) */ + str = buf; + growline = NULL; + eflags = 0; + goto start; + + while (match_status == 0) { + char *new = xasprintf("%s" "%.*s" "%s" "%.*s" "%s", + growline ? : "", + match_structs.rm_so, str, + HIGHLIGHT, + match_structs.rm_eo - match_structs.rm_so, + str + match_structs.rm_so, + NORMAL); + free(growline); growline = new; + str += match_structs.rm_eo; + line += match_structs.rm_eo; + eflags = REG_NOTBOL; + start: + /* Most of the time doesn't find the regex, optimize for that */ + match_status = regexec(&pattern, line, 1, &match_structs, eflags); + } + + if (!growline) { + puts(str); + return; + } + printf("%s%s\n", growline, str); + free(growline); +} + +static void print_ascii(const char *str) +{ + char buf[width]; + char *p; + size_t n; + + while (*str) { + n = strcspn(str, controls); + if (n) { + if (!str[n]) break; + printf("%.*s", n, str); + str += n; + } + n = strspn(str, controls); + p = buf; + do { + if (*str == '\x7f') { *p++ = '?'; str++; } + else if (*str == '\x9b') { *p++ = '{'; str++; } + else *p++ = ctrlconv[(unsigned char)*str++]; + } while (--n); + *p = '\0'; + printf("%s%s%s", HIGHLIGHT, buf, NORMAL); + } + puts(str); +} + /* Print the buffer */ static void buffer_print(void) { int i; printf("%s", CLEAR); - if (num_flines >= height - 2) { - for (i = 0; i < height - 1; i++) - 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\n", width, buffer[i]); - } - + for (i = 0; i < height - 1; i++) + if (pattern_valid) + print_found(buffer[i]); + else + print_ascii(buffer[i]); status_print(); } @@ -339,20 +427,20 @@ static void buffer_init(void) { int i; - if (buffer == NULL) { + if (!buffer) { /* malloc the number of lines needed for the buffer */ 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++) { + for (i = 0; i < height - 1 && i <= num_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] = ""; + for (; i < height - 1; i++) { + buffer[i] = empty_line_marker; } } @@ -361,72 +449,38 @@ static void buffer_down(int nlines) { int i; - if (!(option_mask32 & LESS_STATE_PAST_EOF)) { - if (line_pos + (height - 3) + nlines < num_flines) { - line_pos += nlines; + 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 { + /* 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]; } - } 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++) { - buffer[i] = flines[line_pos + i]; - } - } } - - /* We exit if the -E flag has been set */ - if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines)) - tless_exit(0); } + + /* We exit if the -E flag has been set */ + if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines)) + tless_exit(0); } static void buffer_up(int nlines) { int i; - int tilde_line; - if (!(option_mask32 & LESS_STATE_PAST_EOF)) { - if (line_pos - nlines >= 0) { - line_pos -= nlines; - for (i = 0; i < (height - 1); i++) { - buffer[i] = flines[line_pos + i]; - } - } 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++) { - buffer[i] = flines[line_pos + i]; - } - } - } - } - else { - /* Work out where the tildes start */ - tilde_line = num_flines - line_pos + 3; - - line_pos -= 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) { - option_mask32 &= ~LESS_STATE_PAST_EOF; - buffer_up(nlines); + 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 { - /* We only move part of the buffer, as the rest - is past the EOF */ - for (i = 0; i < (height - 1); i++) { - if (i < tilde_line - nlines + 1) { - buffer[i] = flines[line_pos + i]; - } else { - if (line_pos >= num_flines - height + 2) - buffer[i] = "~"; - } - } + buffer[i] = empty_line_marker; } } } @@ -434,28 +488,19 @@ static void buffer_up(int nlines) static void buffer_line(int linenum) { int i; - option_mask32 &= ~LESS_STATE_PAST_EOF; if (linenum < 0 || linenum > num_flines) { clear_line(); printf("%s%s%i%s", HIGHLIGHT, "Cannot seek to line number ", linenum + 1, NORMAL); - } - else if (linenum < (num_flines - height - 2)) { - for (i = 0; i < (height - 1); i++) { - buffer[i] = flines[linenum + i]; - } - line_pos = linenum; - buffer_print(); } else { - for (i = 0; i < (height - 1); i++) { - if (linenum + i < num_flines + 2) + for (i = 0; i < height - 1; i++) { + if (linenum + i <= num_flines) buffer[i] = flines[linenum + i]; - else - buffer[i] = (option_mask32 & FLAG_TILDE) ? "" : "~"; + else { + buffer[i] = empty_line_marker; + } } line_pos = linenum; - /* Set past_eof so buffer_down and buffer_up act differently */ - option_mask32 |= LESS_STATE_PAST_EOF; buffer_print(); } } @@ -563,76 +608,37 @@ static void colon_process(void) } } -#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 - file line by line, running a processing regex function on each one. */ - -static char *process_regex_on_line(char *line, regex_t *pattern, int action) +static int normalize_match_pos(int match) { -/* 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 = line; - char *growline = xstrdup(""); - char *ng; - regmatch_t match_structs; - - match_found = 0; - match_status = regexec(pattern, line2, 1, &match_structs, 0); - - while (match_status == 0) { - match_found = 1; - if (action) { - 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 { - 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); - } - - if (match_found) { - ng = xasprintf("%s%s", growline, line2); - free(line); - } else { - ng = line; - } - free(growline); - return ng; + match_pos = match; + if (match < 0) + return (match_pos = 0); + if (match >= num_matches) +{ + match_pos = num_matches - 1; +} + return match_pos; } +#if ENABLE_FEATURE_LESS_REGEXP static void goto_match(int match) { - /* This goes to a specific match - all line positions of matches are - stored within the match_lines[] array. */ - if ((match < num_matches) && (match >= 0)) { - buffer_line(match_lines[match]); - match_pos = match; - } + buffer_line(match_lines[normalize_match_pos(match)]); } static void regex_process(void) { char *uncomp_regex; - int i; - int j = 0; - regex_t pattern; + + /* Reset variables */ + match_lines = xrealloc(match_lines, sizeof(int)); + match_lines[0] = -1; + match_pos = 0; + num_matches = 0; + if (pattern_valid) { + regfree(&pattern); + pattern_valid = 0; + } /* Get the uncompiled regular expression from the user */ clear_line(); @@ -640,56 +646,33 @@ static void regex_process(void) uncomp_regex = xmalloc_getline(inp); if (!uncomp_regex || !uncomp_regex[0]) { free(uncomp_regex); - if (num_matches) - goto_match((option_mask32 & LESS_STATE_MATCH_BACKWARDS) - ? match_pos - 1 : match_pos + 1); - else - buffer_print(); + buffer_print(); return; } /* Compile the regex and check for errors */ xregcomp(&pattern, uncomp_regex, 0); free(uncomp_regex); + pattern_valid = 1; - if (num_matches) { - /* Get rid of all the highlights we added previously */ - for (i = 0; i <= num_flines; i++) { - flines[i] = process_regex_on_line(flines[i], &old_pattern, 0); + /* Run the regex on each line of the current file */ + for (match_pos = 0; match_pos <= num_flines; 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; } } - old_pattern = pattern; - /* Reset variables */ - match_lines = xrealloc(match_lines, sizeof(int)); - match_lines[0] = -1; - match_pos = 0; - num_matches = 0; - match_found = 0; - /* Run the regex on each line of the current file here */ - for (i = 0; i <= num_flines; i++) { - 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; - j++; - } + if (num_matches == 0 || num_flines <= height - 2) { + buffer_print(); + return; } - - num_matches = j; - if ((match_lines[0] != -1) && (num_flines > height - 2)) { - if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) { - for (i = 0; i < num_matches; i++) { - if (match_lines[i] > line_pos) { - match_pos = i - 1; - buffer_line(match_lines[match_pos]); - break; - } - } - } else - buffer_line(match_lines[0]); - } else - buffer_init(); + for (match_pos = 0; match_pos < num_matches; match_pos++) { + if (match_lines[match_pos] > line_pos) + break; + } + if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) match_pos--; + buffer_line(match_lines[normalize_match_pos(match_pos)]); } #endif @@ -1111,11 +1094,16 @@ int less_main(int argc, char **argv) inp = xfopen(CURRENT_TTY, "r"); get_terminal_width_height(fileno(inp), &width, &height); + if (width < 10 || height < 3) + bb_error_msg_and_die("too narrow here"); + + if (option_mask32 & FLAG_TILDE) empty_line_marker = ""; + data_readlines(); + tcgetattr(fileno(inp), &term_orig); signal(SIGTERM, sig_catcher); signal(SIGINT, sig_catcher); - tcgetattr(fileno(inp), &term_orig); term_vi = term_orig; term_vi.c_lflag &= (~ICANON & ~ECHO); |