From 193ba408a4fd3313b1dc2eb5eb25885cfa4363f6 Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Tue, 21 Jul 2015 22:28:09 +0200 Subject: less: improvements to verbose status messages Make verbose status messages (-m/-M flags) behave more like the real `less` command: - fix display of line numbers so they're correct whether lines are being truncated (-S flag) or wrapped. - don't display total lines or percentage when lines are read from stdin: we don't have that information until we reach EOF. When we do reach EOF the additional information is displayed. - when lines are read from a file count the total number of lines so that we can display percentages. Counting lines is avoided until the information is actually needed. If the user pages to EOF the separate read pass can be avoided entirely. Fixes Bug 7586 function old new delta m_status_print 195 382 +187 safe_lineno - 35 +35 reinitialize 172 182 +10 read_lines 675 685 +10 buffer_fill_and_print 178 169 -9 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 3/1 up/down: 242/-9) Total: 233 bytes Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- miscutils/less.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 69 insertions(+), 14 deletions(-) diff --git a/miscutils/less.c b/miscutils/less.c index 90c1038..dd932c5 100644 --- a/miscutils/less.c +++ b/miscutils/less.c @@ -165,6 +165,11 @@ enum { enum { pattern_valid = 0 }; #endif +enum { + READING_FILE = -1, + READING_STDIN = -2 +}; + struct globals { int cur_fline; /* signed */ int kbd_fd; /* fd to get input from */ @@ -188,6 +193,9 @@ struct globals { unsigned current_file; char *filename; char **files; +#if ENABLE_FEATURE_LESS_FLAGS + int num_lines; /* input source if < 0, line count if >= 0 */ +#endif #if ENABLE_FEATURE_LESS_MARKS unsigned num_marks; unsigned mark_lines[15][2]; @@ -229,6 +237,7 @@ struct globals { #define current_file (G.current_file ) #define filename (G.filename ) #define files (G.files ) +#define num_lines (G.num_lines ) #define num_marks (G.num_marks ) #define mark_lines (G.mark_lines ) #if ENABLE_FEATURE_LESS_REGEXP @@ -574,6 +583,10 @@ static void read_lines(void) print_statusline(bb_msg_read_error); } } +#if ENABLE_FEATURE_LESS_FLAGS + else if (eof_error == 0) + num_lines = max_lineno; +#endif fill_match_lines(old_max_fline); #if ENABLE_FEATURE_LESS_REGEXP @@ -584,18 +597,23 @@ static void read_lines(void) } #if ENABLE_FEATURE_LESS_FLAGS -/* Interestingly, writing calc_percent as a function saves around 32 bytes - * on my build. */ -static int calc_percent(void) +static int safe_lineno(int fline) { - unsigned p = (100 * (cur_fline+max_displayed_line+1) + max_fline/2) / (max_fline+1); - return p <= 100 ? p : 100; + if (fline >= max_fline) + fline = max_fline - 1; + + /* also catches empty file (max_fline == 0) */ + if (fline < 0) + return 0; + + return LINENO(flines[fline]) + 1; } /* Print a status line if -M was specified */ static void m_status_print(void) { - int percentage; + int first, last; + unsigned percent; if (less_gets_pos >= 0) /* don't touch statusline while input is done! */ return; @@ -604,17 +622,51 @@ static void m_status_print(void) printf(HIGHLIGHT"%s", filename); if (num_files > 1) printf(" (file %i of %i)", current_file, num_files); - printf(" lines %i-%i/%i ", - cur_fline + 1, cur_fline + max_displayed_line + 1, - max_fline + 1); + + first = safe_lineno(cur_fline); + last = (option_mask32 & FLAG_S) + ? MIN(first + max_displayed_line, max_lineno) + : safe_lineno(cur_fline + max_displayed_line); + printf(" lines %i-%i", first, last); + + if (num_lines == READING_FILE) { + int count, fd; + ssize_t len, i; + char buf[4096]; + struct stat stbuf; + + /* count number of lines in file */ + count = 0; + fd = open(filename, O_RDONLY); + if (fd < 0) + goto skip; + if (fstat(fd, &stbuf) != 0 || !S_ISREG(stbuf.st_mode)) + goto do_close; + while ((len = safe_read(fd, buf, sizeof(buf))) > 0) { + for (i = 0; i < len; ++i) { + if (buf[i] == '\n' && ++count == MAXLINES) + goto done; + } + } + done: + num_lines = count; + do_close: + close(fd); + skip: ; + } + + if (num_lines >= 0) + printf("/%i", num_lines); + if (cur_fline >= (int)(max_fline - max_displayed_line)) { - printf("(END)"NORMAL); + printf(" (END)"); if (num_files > 1 && current_file != num_files) - printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]); - return; + printf(" - next: %s", files[current_file]); + } else if (num_lines > 0) { + percent = (100 * last + num_lines/2) / num_lines; + printf(" %i%%", percent <= 100 ? percent : 100); } - percentage = calc_percent(); - printf("%i%%"NORMAL, percentage); + printf(NORMAL); } #endif @@ -915,6 +967,9 @@ static void reinitialize(void) max_fline = -1; cur_fline = 0; max_lineno = 0; +#if ENABLE_FEATURE_LESS_FLAGS + num_lines = filename ? READING_FILE : READING_STDIN; +#endif open_file_and_read_lines(); #if ENABLE_FEATURE_LESS_ASK_TERMINAL if (G.winsize_err) -- cgit v1.1