[PATCH] Readline's mimic for reverse history search
kyak
bas at bmail.ru
Fri Jul 8 04:37:50 UTC 2011
Hi, just wanted to remind in case this patch got lost in the mailing
list.
Thank you!
On Mon, 4 Jul 2011, kyak wrote:
> Implemented readline's mimic for reverse history search (Ctrl+r).
> Reworked based on Denys Vlasenko remarks.
>
> Signed-off-by: kyak <bas at bmail.ru>
> ---
> libbb/Config.src | 7 ++
> libbb/lineedit.c | 212
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 219 insertions(+), 0 deletions(-)
>
> diff --git a/libbb/Config.src b/libbb/Config.src
> index 0ea8f43..3b1487d 100644
> --- a/libbb/Config.src
> +++ b/libbb/Config.src
> @@ -94,6 +94,13 @@ config FEATURE_EDITING_SAVEHISTORY
> help
> Enable history saving in shells.
>
> +config FEATURE_REVERSE_SEARCH
> + bool "Reverse history search"
> + default n
> + depends on FEATURE_EDITING_SAVEHISTORY
> + help
> + Enable readline-alike Ctrl+r combination for reverse history search
> +
> config FEATURE_TAB_COMPLETION
> bool "Tab completion"
> default y
> diff --git a/libbb/lineedit.c b/libbb/lineedit.c
> index 4e3bc0e..f18d9cb 100644
> --- a/libbb/lineedit.c
> +++ b/libbb/lineedit.c
> @@ -1948,6 +1948,213 @@ static int isrtl_str(void)
> #undef CTRL
> #define CTRL(a) ((a) & ~0x40)
>
> +#if ENABLE_FEATURE_REVERSE_SEARCH
> +/* Mimic readline's Ctrl+r behaviour for reverse history search.
> + * Search backward starting at the current line and moving `up'
> + * through the history as necessary. This is an incremental
> + * search, i.e. hitting Ctrl+r again would search for the next
> + * match in history. */
> +static smallint reverse_i_search(void)
> +{
> + /* prepare the prompt */
> + static const char prmt[] = "(reverse-i-search)`";
> + int prmt_len = sizeof(prmt)-1;
> + char *prmt_mem_ptr = xzalloc(1);
> + /* save the real prompt */
> + char *prmt_mem_ptr_save = xzalloc(1);
> + /* user input is collected here */
> + char *match_buf;
> + /* matched lines from history are here */
> + char *cmdline_buf;
> + char read_key_buffer[KEYCODE_BUFFER_SIZE];
> + int ic;
> + wchar_t wc[MAX_LINELEN];
> + ssize_t len, len_cmd, match_buf_len;
> +#if ENABLE_UNICODE_SUPPORT
> + mbstate_t mbst = { 0 };
> + char buf[MB_CUR_MAX + 1];
> +#endif
> + smallint break_out, has_match;
> + int cur, cur_match;
> + int cmdedit_y_add, cmdedit_y_add_prev, cmdedit_y_add_cmp;
> +
> + break_out = 0;
> + has_match = 0;
> + cur = state->cur_history;
> + cur_match = state->cur_history;
> + cmdedit_y_add = 0;
> + cmdedit_y_add_prev = 0;
> + cmdedit_y_add_cmp = 0;
> + read_key_buffer[0] = 0;
> + prmt_mem_ptr = xstrdup(prmt);
> + /* save prompt */
> + prmt_mem_ptr_save = xstrdup(cmdedit_prompt);
> + /* overwrite the prompt */
> + cmdedit_prompt = prmt_mem_ptr;
> + cmdedit_prmt_len = prmt_len;
> + /* save what's already typed.
> + * MAX_LINELEN * sizeof(int16_t) will be enough, see the comment
> + * in TAB completion function input_tab */
> + match_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
> + cmdline_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
> + save_string(match_buf, MAX_LINELEN);
> + command_len = load_string("", MAX_LINELEN);
> + redraw(cmdedit_y, 0);
> + fputs(match_buf, stdout);
> + fputs("': ", stdout);
> + fputs(match_buf, stdout);
> + cmdedit_y_add_cmp = (prmt_len+1 + 2 * strlen(match_buf)) /
> (cmdedit_termw);
> + cmdedit_y_add_prev = cmdedit_y_add_cmp;
> + /* switch to char-consumption mode... */
> + while (1) {
> + fflush_all();
> + ic = lineedit_read_key(read_key_buffer, -1);
> + switch (ic) {
> + case KEYCODE_RIGHT: /* left-right keys act
> differently from Enter */
> + case KEYCODE_LEFT:
> + if (has_match == 1) {
> + command_len =
> load_string(cmdline_buf, MAX_LINELEN);
> + } else {
> + command_len = load_string(match_buf,
> MAX_LINELEN);
> + }
> + cmdedit_prompt = prmt_mem_ptr_save;
> + cmdedit_prmt_len = strlen(cmdedit_prompt);
> + redraw(cmdedit_y + cmdedit_y_add, 0);
> + break_out = 0;
> + break;
> + case CTRL('R'): /* searching for the next match */
> + break_out = 2;
> + break;
> + case CTRL('C'):
> + case KEYCODE_UP:
> + case KEYCODE_DOWN:
> + case KEYCODE_HOME:
> + case KEYCODE_END:
> + case KEYCODE_DELETE:
> + case KEYCODE_CTRL_RIGHT:
> + case KEYCODE_CTRL_LEFT:
> + case '\x1b': /* ESC */
> + command_len = load_string("", MAX_LINELEN);
> + cmdedit_prompt = prmt_mem_ptr_save;
> + redraw(cmdedit_y + cmdedit_y_add, 0);
> + break_out = 0;
> + break;
> + case '\b': /* ^H */
> + case '\x7f': /* DEL */
> +#if ENABLE_UNICODE_SUPPORT
> + /* convert to wide char string,
> + * delete char, then convert back */
> + len = mbstowcs(wc, match_buf, sizeof(wc));
> + if (len < 0)
> + len = 0;
> + wc[len-1] = '\0';
> + wcstombs(match_buf, wc, MAX_LINELEN);
> +#else
> + match_buf[strlen(match_buf)-1] = '\0';
> +#endif
> + break_out = 2;
> + has_match = 0;
> + break;
> + case '\r':
> + case '\n': /* Enter */
> + if (has_match == 1) {
> + command_len =
> load_string(cmdline_buf, MAX_LINELEN);
> + } else {
> + command_len = load_string(match_buf,
> MAX_LINELEN);
> + }
> + cmdedit_prompt = prmt_mem_ptr_save;
> + redraw(cmdedit_y + cmdedit_y_add, 0);
> + goto_new_line();
> + break_out = 1;
> + break;
> + default: /* process the char */
> +#if ENABLE_UNICODE_SUPPORT
> + len = wcrtomb(buf, ic, &mbst);
> + if (len > 0) {
> + buf[len] = '\0';
> + }
> + strncat(match_buf, buf, sizeof(match_buf)-1);
> +#else
> + snprintf(&match_buf[strlen(match_buf)],
> sizeof(match_buf)-1,
> + "%c", ic);
> +#endif
> + break_out = 2;
> + break;
> + }
> + if (break_out != 2)
> + break;
> + /* if there is something in type buffer,
> + * do iterative search in history */
> + if (match_buf[0] != '\0') {
> + /* save current position in history */
> + cur = state->cur_history;
> + if (ic != CTRL('R')) {
> + cur_match = state->cur_history;
> + } else {
> + /* if we hit Ctrl+r (again),
> + * start searching from the last matched
> position */
> + state->cur_history = cur_match;
> + }
> + while(get_previous_history()) {
> + cmdline_buf =
> state->history[state->cur_history];
> + has_match = 0;
> + match_buf_len = strlen(match_buf);
> + for(int
> i=0;i+match_buf_len<=strlen(cmdline_buf);i++) {
> + if (strncmp(match_buf, cmdline_buf+i,
> match_buf_len) == 0) {
> + has_match = 1;
> + /* save position of current
> match */
> + cur_match =
> state->cur_history;
> + goto break_out_search;
> + }
> + }
> + }
> + }
> + break_out_search:
> + /* TODO: this could be done better. There are still some
> (rare)
> + * cases of wrapping miscalculation */
> + len = mbstowcs(wc, match_buf, sizeof(wc));
> + if (len < 0)
> + len = strlen(match_buf);
> +
> + len_cmd = mbstowcs(wc, cmdline_buf, sizeof(wc));
> + if (len_cmd < 0)
> + len_cmd = strlen(cmdline_buf);
> +
> + cmdedit_y_add = (prmt_len+1 + len + (has_match ? len_cmd :
> len)) /
> + (cmdedit_termw);
> +
> + if (cmdedit_y_add > cmdedit_y_add_cmp) {
> + int t = cmdedit_y_add - cmdedit_y_add_cmp;
> + for (int j = 1; j <= t; j++) {
> + /* scroll up */
> + printf(ESC"D");
> + }
> + if (t > 1)
> + redraw(cmdedit_y + t, 0);
> + else
> + redraw(cmdedit_y + cmdedit_y_add, 0);
> + cmdedit_y_add_cmp = cmdedit_y_add;
> + } else if (cmdedit_y_add != cmdedit_y_add_prev) {
> + redraw(cmdedit_y + cmdedit_y_add_prev, 0);
> + } else {
> + redraw(cmdedit_y + cmdedit_y_add, 0);
> + }
> +
> + fputs(match_buf, stdout);
> + fputs("': ", stdout);
> + if (has_match == 0) {
> + fputs(match_buf, stdout);
> + } else {
> + fputs(cmdline_buf, stdout);
> + }
> + cmdedit_y_add_prev = cmdedit_y_add;
> + /* restore current position in history */
> + state->cur_history=cur;
> + } /* !while */
> + return break_out;
> +}
> +#endif
> +
> /* maxsize must be >= 2.
> * Returns:
> * -1 on read errors or EOF, or on bare Ctrl-D,
> @@ -2174,6 +2381,11 @@ int FAST_FUNC read_line_input(line_input_t *st, const
> char *prompt, char *comman
> while (cursor > 0 &&
> !BB_isspace(command_ps[cursor-1]))
> input_backspace();
> break;
> +#if ENABLE_FEATURE_REVERSE_SEARCH
> + case CTRL('R'):
> + break_out = reverse_i_search();
> + break;
> +#endif
>
> #if ENABLE_FEATURE_EDITING_VI
> case 'i'|VI_CMDMODE_BIT:
> --
> 1.7.1
>
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