From c175c4664734e5a363d8cc8668c08f551eff1485 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 18 Apr 2010 22:09:30 -0700 Subject: [PATCH] vi: discover window size even on serial consoles. optional function old new delta edit_file 671 761 +90 wh_helper - 57 +57 query_screen_dimensions 54 63 +9 ar_main 533 542 +9 refresh 767 773 +6 vi_main 242 243 +1 text_yank 56 54 -2 get_terminal_width_height 180 135 -45 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 5/2 up/down: 172/-47) Total: 125 bytes Signed-off-by: Denys Vlasenko --- editors/Config.in | 12 +++++++++++ editors/vi.c | 23 +++++++++++++++++++- libbb/read_key.c | 2 +- libbb/xfuncs.c | 54 ++++++++++++++++++++++++++--------------------- 4 files changed, 65 insertions(+), 26 deletions(-) diff --git a/editors/Config.in b/editors/Config.in index e4fdd0f38..5f9566f0a 100644 --- a/editors/Config.in +++ b/editors/Config.in @@ -168,6 +168,18 @@ config FEATURE_VI_WIN_RESIZE help Make busybox vi behave nicely with terminals that get resized. +config FEATURE_VI_ASK_TERMINAL + bool "Use 'tell me cursor position' ESC sequence to measure window" + default n + depends on VI + help + If terminal size can't be retrieved and $LINES/$COLUMNS are not set, + this option makes vi perform a last-ditch effort to find it: + vi positions cursor to 999,999 and asks terminal to report real + cursor position using "ESC [ 6 n" escape sequence, then reads stdin. + + This is not clean but helps a lot on serial lines and such. + config FEATURE_VI_OPTIMIZE_CURSOR bool "Optimize cursor movement" default y diff --git a/editors/vi.c b/editors/vi.c index f925984ba..d3a35e781 100644 --- a/editors/vi.c +++ b/editors/vi.c @@ -138,6 +138,9 @@ struct globals { int save_argc; // how many file names on cmd line int cmdcnt; // repetition count unsigned rows, columns; // the terminal screen is this size +#if ENABLE_FEATURE_VI_ASK_TERMINAL + int get_rowcol_error; +#endif int crow, ccol; // cursor is on Crow x Ccol int offset; // chars scrolled off the screen to the left int have_status_msg; // is default edit status needed? @@ -503,7 +506,11 @@ static int init_text_buffer(char *fn) #if ENABLE_FEATURE_VI_WIN_RESIZE static void query_screen_dimensions(void) { - get_terminal_width_height(STDIN_FILENO, &columns, &rows); +# if ENABLE_FEATURE_VI_ASK_TERMINAL + if (!G.get_rowcol_error) + G.get_rowcol_error = +# endif + get_terminal_width_height(STDIN_FILENO, &columns, &rows); if (rows > MAX_SCR_ROWS) rows = MAX_SCR_ROWS; if (columns > MAX_SCR_COLS) @@ -530,6 +537,20 @@ static void edit_file(char *fn) columns = 80; size = 0; query_screen_dimensions(); +#if ENABLE_FEATURE_VI_ASK_TERMINAL + if (G.get_rowcol_error /* TODO? && no input on stdin */) { + uint64_t k; + write1("\033[999;999H" "\033[6n"); + fflush_all(); + k = read_key(STDIN_FILENO, readbuffer, /*timeout_ms:*/ 100); + if ((int32_t)k == KEYCODE_CURSOR_POS) { + uint32_t rc = (k >> 32); + columns = (rc & 0x7fff); + rows = ((rc >> 16) & 0x7fff); + } + query_screen_dimensions(); + } +#endif new_screen(rows, columns); // get memory for virtual screen init_text_buffer(fn); diff --git a/libbb/read_key.c b/libbb/read_key.c index 8422976c9..64557ab14 100644 --- a/libbb/read_key.c +++ b/libbb/read_key.c @@ -214,7 +214,7 @@ int64_t FAST_FUNC read_key(int fd, char *buffer, int timeout) } n++; /* Try to decipher "ESC [ NNN ; NNN R" sequence */ - if (ENABLE_FEATURE_EDITING_ASK_TERMINAL + if ((ENABLE_FEATURE_EDITING_ASK_TERMINAL || ENABLE_FEATURE_VI_ASK_TERMINAL) && n >= 5 && buffer[0] == '[' && buffer[n-1] == 'R' diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c index aec165f06..d93dd2af9 100644 --- a/libbb/xfuncs.c +++ b/libbb/xfuncs.c @@ -210,34 +210,40 @@ char* FAST_FUNC xmalloc_ttyname(int fd) return buf; } -/* It is perfectly ok to pass in a NULL for either width or for - * height, in which case that value will not be set. */ -int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height) +static int wh_helper(int value, int def_val, const char *env_name, int *err) { - struct winsize win = { 0, 0, 0, 0 }; - int ret = ioctl(fd, TIOCGWINSZ, &win); - - if (height) { - if (!win.ws_row) { - char *s = getenv("LINES"); - if (s) win.ws_row = atoi(s); - } - if (win.ws_row <= 1 || win.ws_row >= 30000) - win.ws_row = 24; - *height = (int) win.ws_row; - } - - if (width) { - if (!win.ws_col) { - char *s = getenv("COLUMNS"); - if (s) win.ws_col = atoi(s); + if (value == 0) { + char *s = getenv(env_name); + if (s) { + value = atoi(s); + /* If LINES/COLUMNS are set, pretent that there is + * no error getting w/h, this prevents some ugly + * cursor tricks by our callers */ + *err = 0; } - if (win.ws_col <= 1 || win.ws_col >= 30000) - win.ws_col = 80; - *width = (int) win.ws_col; } + if (value <= 1 || value >= 30000) + value = def_val; + return value; +} - return ret; +/* It is perfectly ok to pass in a NULL for either width or for + * height, in which case that value will not be set. */ +int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height) +{ + struct winsize win; + int err; + + win.ws_row = 0; + win.ws_col = 0; + /* I've seen ioctl returning 0, but row/col is (still?) 0. + * We treat that as an error too. */ + err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0; + if (height) + *height = wh_helper(win.ws_row, 24, "LINES", &err); + if (width) + *width = wh_helper(win.ws_col, 80, "COLUMNS", &err); + return err; } int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp) -- 2.25.1