diff options
| -rw-r--r-- | libbb/lineedit.c | 88 |
1 files changed, 64 insertions, 24 deletions
diff --git a/libbb/lineedit.c b/libbb/lineedit.c index 3a092ff..c0e35bb 100644 --- a/libbb/lineedit.c +++ b/libbb/lineedit.c @@ -37,11 +37,6 @@ * * Unicode in PS1 is not fully supported: prompt length calulation is wrong, * resulting in line wrap problems with long (multi-line) input. - * - * Multi-line PS1 (e.g. PS1="\n[\w]\n$ ") has problems with history - * browsing: up/down arrows result in scrolling. - * It stems from simplistic "cmdedit_y = cmdedit_prmt_len / cmdedit_termw" - * calculation of how many lines the prompt takes. */ #include "busybox.h" #include "NUM_APPLETS.h" @@ -133,7 +128,7 @@ struct lineedit_statics { unsigned cmdedit_x; /* real x (col) terminal position */ unsigned cmdedit_y; /* pseudoreal y (row) terminal position */ - unsigned cmdedit_prmt_len; /* length of prompt (without colors etc) */ + unsigned cmdedit_prmt_len; /* on-screen length of last/sole prompt line */ unsigned cursor; int command_len; /* must be signed */ @@ -143,6 +138,7 @@ struct lineedit_statics { CHAR_T *command_ps; const char *cmdedit_prompt; + const char *prompt_last_line; /* last/sole prompt line */ #if ENABLE_USERNAME_OR_HOMEDIR char *user_buf; @@ -185,6 +181,7 @@ extern struct lineedit_statics *const lineedit_ptr_to_statics; #define command_len (S.command_len ) #define command_ps (S.command_ps ) #define cmdedit_prompt (S.cmdedit_prompt ) +#define prompt_last_line (S.prompt_last_line) #define user_buf (S.user_buf ) #define home_pwd_buf (S.home_pwd_buf ) #define matches (S.matches ) @@ -437,14 +434,20 @@ static void beep(void) bb_putchar('\007'); } -static void put_prompt(void) +/* Full or last/sole prompt line, reset edit cursor, calculate terminal cursor. + * cmdedit_y is always calculated for the last/sole prompt line. + */ +static void put_prompt_custom(bool is_full) { - fputs(cmdedit_prompt, stdout); + fputs((is_full ? cmdedit_prompt : prompt_last_line), stdout); cursor = 0; cmdedit_y = cmdedit_prmt_len / cmdedit_termw; /* new quasireal y */ cmdedit_x = cmdedit_prmt_len % cmdedit_termw; } +#define put_prompt_last_line() put_prompt_custom(0) +#define put_prompt() put_prompt_custom(1) + /* Move back one character */ /* (optimized for slow terminals) */ static void input_backward(unsigned num) @@ -509,7 +512,7 @@ static void input_backward(unsigned num) printf("\r" ESC"[%uA", cmdedit_y); cmdedit_y = 0; sv_cursor = cursor; - put_prompt(); /* sets cursor to 0 */ + put_prompt_last_line(); /* sets cursor to 0 */ while (cursor < sv_cursor) put_cur_glyph_and_inc_cursor(); } else { @@ -530,18 +533,27 @@ static void input_backward(unsigned num) } } -/* draw prompt, editor line, and clear tail */ -static void redraw(int y, int back_cursor) +/* See redraw and draw_full below */ +static void draw_custom(int y, int back_cursor, bool is_full) { if (y > 0) /* up y lines */ printf(ESC"[%uA", y); bb_putchar('\r'); - put_prompt(); + put_prompt_custom(is_full); put_till_end_and_adv_cursor(); printf(SEQ_CLEAR_TILL_END_OF_SCREEN); input_backward(back_cursor); } +/* Move y lines up, draw last/sole prompt line, editor line[s], and clear tail. + * goal: redraw the prompt+input+cursor in-place, overwriting the previous */ +#define redraw(y, back_cursor) draw_custom((y), (back_cursor), 0) + +/* Like above, but without moving up, and while using all the prompt lines. + * goal: draw a full prompt+input+cursor unrelated to a previous position. + * note: cmdedit_y always ends up relating to the last/sole prompt line */ +#define draw_full(back_cursor) draw_custom(0, (back_cursor), 1) + /* Delete the char in front of the cursor, optionally saving it * for later putback */ #if !ENABLE_FEATURE_EDITING_VI @@ -1106,7 +1118,7 @@ static NOINLINE void input_tab(smallint *lastWasTab) int sav_cursor = cursor; goto_new_line(); showfiles(); - redraw(0, command_len - sav_cursor); + draw_full(command_len - sav_cursor); } return; } @@ -1782,14 +1794,37 @@ static void ask_terminal(void) #define ask_terminal() ((void)0) #endif +/* Note about multi-line PS1 (e.g. "\n\w \u@\h\n> ") and prompt redrawing: + * + * If the prompt has any newlines, after we print it once we use only its last + * line to redraw in-place, which makes it simpler to calculate how many lines + * we should move the cursor up to align the redraw (cmdedit_y). The earlier + * prompt lines just stay on screen and we redraw below them. + * + * Use cases for all prompt lines beyond the initial draw: + * - After clear-screen (^L) or after displaying tab-completion choices, we + * print the full prompt, as it isn't redrawn in-place. + * - During terminal resize we could try to redraw all lines, but we don't, + * because it requires delicate alignment, it's good enough with only the + * last line, and doing it wrong is arguably worse than not doing it at all. + * + * Terminology wise, if it doesn't mention "full", then it means the last/sole + * prompt line. We use the prompt (last/sole line) while redrawing in-place, + * and the full where we need a fresh one unrelated to an earlier position. + * + * If PS1 is not multiline, the last/sole line and the full are the same string. + */ + /* Called just once at read_line_input() init time */ #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT static void parse_and_put_prompt(const char *prmt_ptr) { const char *p; - cmdedit_prompt = prmt_ptr; + cmdedit_prompt = prompt_last_line = prmt_ptr; p = strrchr(prmt_ptr, '\n'); - cmdedit_prmt_len = unicode_strwidth(p ? p+1 : prmt_ptr); + if (p) + prompt_last_line = p + 1; + cmdedit_prmt_len = unicode_strwidth(prompt_last_line); put_prompt(); } #else @@ -1973,7 +2008,11 @@ static void parse_and_put_prompt(const char *prmt_ptr) if (cwd_buf != (char *)bb_msg_unknown) free(cwd_buf); # endif - cmdedit_prompt = prmt_mem_ptr; + /* see comment (above this function) about multiline prompt redrawing */ + cmdedit_prompt = prompt_last_line = prmt_mem_ptr; + prmt_ptr = strrchr(cmdedit_prompt, '\n'); + if (prmt_ptr) + prompt_last_line = prmt_ptr + 1; put_prompt(); } #endif @@ -2145,7 +2184,7 @@ static int32_t reverse_i_search(int timeout) match_buf[0] = '\0'; /* Save and replace the prompt */ - saved_prompt = cmdedit_prompt; + saved_prompt = prompt_last_line; saved_prmt_len = cmdedit_prmt_len; goto set_prompt; @@ -2218,10 +2257,10 @@ static int32_t reverse_i_search(int timeout) cursor = match - matched_history_line; //FIXME: cursor position for Unicode case - free((char*)cmdedit_prompt); + free((char*)prompt_last_line); set_prompt: - cmdedit_prompt = xasprintf("(reverse-i-search)'%s': ", match_buf); - cmdedit_prmt_len = unicode_strwidth(cmdedit_prompt); + prompt_last_line = xasprintf("(reverse-i-search)'%s': ", match_buf); + cmdedit_prmt_len = unicode_strwidth(prompt_last_line); goto do_redraw; } } @@ -2241,8 +2280,8 @@ static int32_t reverse_i_search(int timeout) if (matched_history_line) command_len = load_string(matched_history_line); - free((char*)cmdedit_prompt); - cmdedit_prompt = saved_prompt; + free((char*)prompt_last_line); + prompt_last_line = saved_prompt; cmdedit_prmt_len = saved_prmt_len; redraw(cmdedit_y, command_len - cursor); @@ -2451,8 +2490,9 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman case CTRL('L'): vi_case(CTRL('L')|VI_CMDMODE_BIT:) /* Control-l -- clear screen */ - printf(ESC"[H"); /* cursor to top,left */ - redraw(0, command_len - cursor); + /* cursor to top,left; clear to the end of screen */ + printf(ESC"[H" ESC"[J"); + draw_full(command_len - cursor); break; #if MAX_HISTORY > 0 case CTRL('N'): |