lineedit: add support for history saving on exit
[oweals/busybox.git] / libbb / lineedit.c
index b7a2b31dc3dfa28887aaeda50cde76b1a31563a3..0786f9ae6bd7c0ab676b67339c2f40b469cd3ace 100644 (file)
  */
 #include "libbb.h"
 #include "unicode.h"
+#ifndef _POSIX_VDISABLE
+# define _POSIX_VDISABLE '\0'
+#endif
+
 
 #ifdef TEST
 # define ENABLE_FEATURE_EDITING 0
@@ -184,6 +188,7 @@ extern struct lineedit_statics *const lineedit_ptr_to_statics;
        IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines = 1;) \
        IF_USERNAME_OR_HOMEDIR(home_pwd_buf = (char*)null_str;) \
 } while (0)
+
 static void deinit_S(void)
 {
 #if ENABLE_FEATURE_EDITING_FANCY_PROMPT
@@ -202,18 +207,21 @@ static void deinit_S(void)
 
 
 #if ENABLE_UNICODE_SUPPORT
-static size_t load_string(const char *src, int maxsize)
+static size_t load_string(const char *src)
 {
        if (unicode_status == UNICODE_ON) {
-               ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
+               ssize_t len = mbstowcs(command_ps, src, S.maxsize - 1);
                if (len < 0)
                        len = 0;
                command_ps[len] = BB_NUL;
                return len;
        } else {
                unsigned i = 0;
-               while ((command_ps[i] = src[i]) != 0)
+               while (src[i] && i < S.maxsize - 1) {
+                       command_ps[i] = src[i];
                        i++;
+               }
+               command_ps[i] = BB_NUL;
                return i;
        }
 }
@@ -314,9 +322,9 @@ static wchar_t adjust_width_and_validate_wc(wchar_t wc)
        return wc;
 }
 #else /* !UNICODE */
-static size_t load_string(const char *src, int maxsize)
+static size_t load_string(const char *src)
 {
-       safe_strncpy(command_ps, src, maxsize);
+       safe_strncpy(command_ps, src, S.maxsize);
        return strlen(command_ps);
 }
 # if ENABLE_FEATURE_TAB_COMPLETION
@@ -1219,10 +1227,10 @@ static NOINLINE void input_tab(smallint *lastWasTab)
                        strcpy(match_buf, &command[cursor_mb]);
                        /* where do we want to have cursor after all? */
                        strcpy(&command[cursor_mb], chosen_match + match_pfx_len);
-                       len = load_string(command, S.maxsize);
+                       len = load_string(command);
                        /* add match and tail */
                        sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, match_buf);
-                       command_len = load_string(command, S.maxsize);
+                       command_len = load_string(command);
                        /* write out the matched command */
                        /* paranoia: load_string can return 0 on conv error,
                         * prevent passing pos = (0 - 12) to redraw */
@@ -1243,12 +1251,26 @@ line_input_t* FAST_FUNC new_line_input_t(int flags)
 {
        line_input_t *n = xzalloc(sizeof(*n));
        n->flags = flags;
+       n->max_history = MAX_HISTORY;
        return n;
 }
 
 
 #if MAX_HISTORY > 0
 
+unsigned size_from_HISTFILESIZE(const char *hp)
+{
+       int size = MAX_HISTORY;
+       if (hp) {
+               size = atoi(hp);
+               if (size <= 0)
+                       return 1;
+               if (size > MAX_HISTORY)
+                       return MAX_HISTORY;
+       }
+       return size;
+}
+
 static void save_command_ps_at_cur_history(void)
 {
        if (command_ps[0] != BB_NUL) {
@@ -1329,7 +1351,9 @@ static void load_history(line_input_t *st_parm)
 
                /* fill temp_h[], retaining only last MAX_HISTORY lines */
                memset(temp_h, 0, sizeof(temp_h));
-               st_parm->cnt_history_in_file = idx = 0;
+               idx = 0;
+               if (!ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                       st_parm->cnt_history_in_file = 0;
                while ((line = xmalloc_fgetline(fp)) != NULL) {
                        if (line[0] == '\0') {
                                free(line);
@@ -1337,9 +1361,10 @@ static void load_history(line_input_t *st_parm)
                        }
                        free(temp_h[idx]);
                        temp_h[idx] = line;
-                       st_parm->cnt_history_in_file++;
+                       if (!ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                               st_parm->cnt_history_in_file++;
                        idx++;
-                       if (idx == MAX_HISTORY)
+                       if (idx == st_parm->max_history)
                                idx = 0;
                }
                fclose(fp);
@@ -1348,18 +1373,18 @@ static void load_history(line_input_t *st_parm)
                if (st_parm->cnt_history_in_file) {
                        while (temp_h[idx] == NULL) {
                                idx++;
-                               if (idx == MAX_HISTORY)
+                               if (idx == st_parm->max_history)
                                        idx = 0;
                        }
                }
 
                /* copy temp_h[] to st_parm->history[] */
-               for (i = 0; i < MAX_HISTORY;) {
+               for (i = 0; i < st_parm->max_history;) {
                        line = temp_h[idx];
                        if (!line)
                                break;
                        idx++;
-                       if (idx == MAX_HISTORY)
+                       if (idx == st_parm->max_history)
                                idx = 0;
                        line_len = strlen(line);
                        if (line_len >= MAX_LINELEN)
@@ -1367,15 +1392,66 @@ static void load_history(line_input_t *st_parm)
                        st_parm->history[i++] = line;
                }
                st_parm->cnt_history = i;
+               if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT)
+                       st_parm->cnt_history_in_file = i;
        }
 }
 
-/* state->flags is already checked to be nonzero */
+#  if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+void save_history(line_input_t *st)
+{
+       FILE *fp;
+
+       if (!(st->flags & SAVE_HISTORY))
+               return;
+       if (!st->hist_file)
+               return;
+       if (st->cnt_history <= st->cnt_history_in_file)
+               return;
+
+       fp = fopen(st->hist_file, "a");
+       if (fp) {
+               int i, fd;
+               char *new_name;
+               line_input_t *st_temp;
+
+               for (i = st->cnt_history_in_file; i < st->cnt_history; i++)
+                       fprintf(fp, "%s\n", st->history[i]);
+               fclose(fp);
+
+               /* we may have concurrently written entries from others.
+                * load them */
+               st_temp = new_line_input_t(st->flags);
+               st_temp->hist_file = st->hist_file;
+               st_temp->max_history = st->max_history;
+               load_history(st_temp);
+
+               /* write out temp file and replace hist_file atomically */
+               new_name = xasprintf("%s.%u.new", st->hist_file, (int) getpid());
+               fd = open(new_name, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+               if (fd >= 0) {
+                       fp = xfdopen_for_write(fd);
+                       for (i = 0; i < st_temp->cnt_history; i++)
+                               fprintf(fp, "%s\n", st_temp->history[i]);
+                       fclose(fp);
+                       if (rename(new_name, st->hist_file) == 0)
+                               st->cnt_history_in_file = st_temp->cnt_history;
+               }
+               free(new_name);
+               free_line_input_t(st_temp);
+       }
+}
+#  else
 static void save_history(char *str)
 {
        int fd;
        int len, len2;
 
+       if (!(state->flags & SAVE_HISTORY))
+               return;
+       if (!state->hist_file)
+               return;
+
        fd = open(state->hist_file, O_WRONLY | O_CREAT | O_APPEND, 0600);
        if (fd < 0)
                return;
@@ -1390,7 +1466,7 @@ static void save_history(char *str)
 
        /* did we write so much that history file needs trimming? */
        state->cnt_history_in_file++;
-       if (state->cnt_history_in_file > MAX_HISTORY * 4) {
+       if (state->cnt_history_in_file > state->max_history * 4) {
                char *new_name;
                line_input_t *st_temp;
 
@@ -1398,11 +1474,12 @@ static void save_history(char *str)
                 * load them */
                st_temp = new_line_input_t(state->flags);
                st_temp->hist_file = state->hist_file;
+               st_temp->max_history = state->max_history;
                load_history(st_temp);
 
                /* write out temp file and replace hist_file atomically */
                new_name = xasprintf("%s.%u.new", state->hist_file, (int) getpid());
-               fd = open(state->hist_file, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+               fd = open(new_name, O_WRONLY | O_CREAT | O_TRUNC, 0600);
                if (fd >= 0) {
                        FILE *fp;
                        int i;
@@ -1418,6 +1495,7 @@ static void save_history(char *str)
                free_line_input_t(st_temp);
        }
 }
+#  endif
 # else
 #  define load_history(a) ((void)0)
 #  define save_history(a) ((void)0)
@@ -1436,25 +1514,26 @@ static void remember_in_history(char *str)
        if (i && strcmp(state->history[i-1], str) == 0)
                return;
 
-       free(state->history[MAX_HISTORY]); /* redundant, paranoia */
-       state->history[MAX_HISTORY] = NULL; /* redundant, paranoia */
+       free(state->history[state->max_history]); /* redundant, paranoia */
+       state->history[state->max_history] = NULL; /* redundant, paranoia */
 
        /* If history[] is full, remove the oldest command */
-       /* we need to keep history[MAX_HISTORY] empty, hence >=, not > */
-       if (i >= MAX_HISTORY) {
+       /* we need to keep history[state->max_history] empty, hence >=, not > */
+       if (i >= state->max_history) {
                free(state->history[0]);
-               for (i = 0; i < MAX_HISTORY-1; i++)
+               for (i = 0; i < state->max_history-1; i++)
                        state->history[i] = state->history[i+1];
-               /* i == MAX_HISTORY-1 */
+               /* i == state->max_history-1 */
+               if (ENABLE_FEATURE_EDITING_SAVE_ON_EXIT && state->cnt_history_in_file)
+                       state->cnt_history_in_file--;
        }
-       /* i <= MAX_HISTORY-1 */
+       /* i <= state->max_history-1 */
        state->history[i++] = xstrdup(str);
-       /* i <= MAX_HISTORY */
+       /* i <= state->max_history */
        state->cur_history = i;
        state->cnt_history = i;
-# if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
-       if ((state->flags & SAVE_HISTORY) && state->hist_file)
-               save_history(str);
+# if ENABLE_FEATURE_EDITING_SAVEHISTORY && !ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
+       save_history(str);
 # endif
        IF_FEATURE_EDITING_FANCY_PROMPT(num_ok_lines++;)
 }
@@ -1661,7 +1740,7 @@ static void ask_terminal(void)
         * write(1, "~/srcdevel/bbox/fix/busybox.t4 # ", 33) = 33
         * poll([{fd=0, events=POLLIN}], 1, 0) = 0 (Timeout)  <-- no input exists
         * write(1, "\33[6n", 4) = 4  <-- send the ESC sequence, quick!
-        * poll([{fd=0, events=POLLIN}], 1, 4294967295) = 1 ([{fd=0, revents=POLLIN}])
+        * poll([{fd=0, events=POLLIN}], 1, -1) = 1 ([{fd=0, revents=POLLIN}])
         * read(0, "\n", 1)      = 1  <-- oh crap, user's input got in first
         */
        struct pollfd pfd;
@@ -1819,10 +1898,11 @@ static void win_changed(int nsig)
 {
        int sv_errno = errno;
        unsigned width;
+
        get_terminal_width_height(0, &width, NULL);
-       cmdedit_setwidth(width, nsig /* - just a yes/no flag */);
-       if (nsig == SIGWINCH)
-               signal(SIGWINCH, win_changed); /* rearm ourself */
+//FIXME: cmdedit_setwidth() -> redraw() -> printf() -> KABOOM! (we are in signal handler!)
+       cmdedit_setwidth(width, /*redraw_flg:*/ nsig);
+
        errno = sv_errno;
 }
 
@@ -1927,6 +2007,140 @@ static int isrtl_str(void)
 #undef CTRL
 #define CTRL(a) ((a) & ~0x40)
 
+enum {
+       VI_CMDMODE_BIT = 0x40000000,
+       /* 0x80000000 bit flags KEYCODE_xxx */
+};
+
+#if ENABLE_FEATURE_REVERSE_SEARCH
+/* Mimic readline Ctrl-R reverse history search.
+ * When invoked, it shows the following prompt:
+ * (reverse-i-search)'': user_input [cursor pos unchanged by Ctrl-R]
+ * and typing results in search being performed:
+ * (reverse-i-search)'tmp': cd /tmp [cursor under t in /tmp]
+ * Search is performed by looking at progressively older lines in history.
+ * Ctrl-R again searches for the next match in history.
+ * Backspace deletes last matched char.
+ * Control keys exit search and return to normal editing (at current history line).
+ */
+static int32_t reverse_i_search(void)
+{
+       char match_buf[128]; /* for user input */
+       char read_key_buffer[KEYCODE_BUFFER_SIZE];
+       const char *matched_history_line;
+       const char *saved_prompt;
+       int32_t ic;
+
+       matched_history_line = NULL;
+       read_key_buffer[0] = 0;
+       match_buf[0] = '\0';
+
+       /* Save and replace the prompt */
+       saved_prompt = cmdedit_prompt;
+       goto set_prompt;
+
+       while (1) {
+               int h;
+               unsigned match_buf_len = strlen(match_buf);
+
+               fflush_all();
+//FIXME: correct timeout?
+               ic = lineedit_read_key(read_key_buffer, -1);
+
+               switch (ic) {
+               case CTRL('R'): /* searching for the next match */
+                       break;
+
+               case '\b':
+               case '\x7f':
+                       /* Backspace */
+                       if (unicode_status == UNICODE_ON) {
+                               while (match_buf_len != 0) {
+                                       uint8_t c = match_buf[--match_buf_len];
+                                       if ((c & 0xc0) != 0x80) /* start of UTF-8 char? */
+                                               break; /* yes */
+                               }
+                       } else {
+                               if (match_buf_len != 0)
+                                       match_buf_len--;
+                       }
+                       match_buf[match_buf_len] = '\0';
+                       break;
+
+               default:
+                       if (ic < ' '
+                        || (!ENABLE_UNICODE_SUPPORT && ic >= 256)
+                        || (ENABLE_UNICODE_SUPPORT && ic >= VI_CMDMODE_BIT)
+                       ) {
+                               goto ret;
+                       }
+
+                       /* Append this char */
+#if ENABLE_UNICODE_SUPPORT
+                       if (unicode_status == UNICODE_ON) {
+                               mbstate_t mbstate = { 0 };
+                               char buf[MB_CUR_MAX + 1];
+                               int len = wcrtomb(buf, ic, &mbstate);
+                               if (len > 0) {
+                                       buf[len] = '\0';
+                                       if (match_buf_len + len < sizeof(match_buf))
+                                               strcpy(match_buf + match_buf_len, buf);
+                               }
+                       } else
+#endif
+                       if (match_buf_len < sizeof(match_buf) - 1) {
+                               match_buf[match_buf_len] = ic;
+                               match_buf[match_buf_len + 1] = '\0';
+                       }
+                       break;
+               } /* switch (ic) */
+
+               /* Search in history for match_buf */
+               h = state->cur_history;
+               if (ic == CTRL('R'))
+                       h--;
+               while (h >= 0) {
+                       if (state->history[h]) {
+                               char *match = strstr(state->history[h], match_buf);
+                               if (match) {
+                                       state->cur_history = h;
+                                       matched_history_line = state->history[h];
+                                       command_len = load_string(matched_history_line);
+                                       cursor = match - matched_history_line;
+//FIXME: cursor position for Unicode case
+
+                                       free((char*)cmdedit_prompt);
+ set_prompt:
+                                       cmdedit_prompt = xasprintf("(reverse-i-search)'%s': ", match_buf);
+                                       cmdedit_prmt_len = strlen(cmdedit_prompt);
+                                       goto do_redraw;
+                               }
+                       }
+                       h--;
+               }
+
+               /* Not found */
+               match_buf[match_buf_len] = '\0';
+               beep();
+               continue;
+
+ do_redraw:
+               redraw(cmdedit_y, command_len - cursor);
+       } /* while (1) */
+
+ ret:
+       if (matched_history_line)
+               command_len = load_string(matched_history_line);
+
+       free((char*)cmdedit_prompt);
+       cmdedit_prompt = saved_prompt;
+       cmdedit_prmt_len = strlen(cmdedit_prompt);
+       redraw(cmdedit_y, command_len - cursor);
+
+       return ic;
+}
+#endif
+
 /* maxsize must be >= 2.
  * Returns:
  * -1 on read errors or EOF, or on bare Ctrl-D,
@@ -1970,7 +2184,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                maxsize = MAX_LINELEN;
        S.maxsize = maxsize;
 
-       /* With null flags, no other fields are ever used */
+       /* With zero flags, no other fields are ever used */
        state = st ? st : (line_input_t*) &const_int_0;
 #if MAX_HISTORY > 0
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -2001,14 +2215,9 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
        new_settings.c_cc[VMIN] = 1;
        new_settings.c_cc[VTIME] = 0;
        /* Turn off CTRL-C, so we can trap it */
-#ifndef _POSIX_VDISABLE
-# define _POSIX_VDISABLE '\0'
-#endif
        new_settings.c_cc[VINTR] = _POSIX_VDISABLE;
        tcsetattr_stdin_TCSANOW(&new_settings);
 
-       previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
-       win_changed(0); /* do initial resizing */
 #if ENABLE_USERNAME_OR_HOMEDIR
        {
                struct passwd *entry;
@@ -2022,7 +2231,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
 #endif
 
 #if 0
-       for (i = 0; i <= MAX_HISTORY; i++)
+       for (i = 0; i <= state->max_history; i++)
                bb_error_msg("history[%d]:'%s'", i, state->history[i]);
        bb_error_msg("cur_history:%d cnt_history:%d", state->cur_history, state->cnt_history);
 #endif
@@ -2031,6 +2240,11 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
        parse_and_put_prompt(prompt);
        ask_terminal();
 
+       /* Install window resize handler (NB: after *all* init is complete) */
+//FIXME: save entire sigaction!
+       previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
+       win_changed(0); /* get initial window size */
+
        read_key_buffer[0] = 0;
        while (1) {
                /*
@@ -2041,15 +2255,14 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                 * clutters the big switch a bit, but keeps all the code
                 * in one place.
                 */
-               enum {
-                       VI_CMDMODE_BIT = 0x40000000,
-                       /* 0x80000000 bit flags KEYCODE_xxx */
-               };
                int32_t ic, ic_raw;
 
                fflush_all();
                ic = ic_raw = lineedit_read_key(read_key_buffer, timeout);
 
+#if ENABLE_FEATURE_REVERSE_SEARCH
+ again:
+#endif
 #if ENABLE_FEATURE_EDITING_VI
                newdelflag = 1;
                if (vi_cmdmode) {
@@ -2153,6 +2366,11 @@ 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'):
+                       ic = ic_raw = reverse_i_search();
+                       goto again;
+#endif
 
 #if ENABLE_FEATURE_EDITING_VI
                case 'i'|VI_CMDMODE_BIT:
@@ -2306,7 +2524,7 @@ int FAST_FUNC read_line_input(line_input_t *st, const char *prompt, char *comman
                        /* Rewrite the line with the selected history item */
                        /* change command */
                        command_len = load_string(state->history[state->cur_history] ?
-                                       state->history[state->cur_history] : "", maxsize);
+                                       state->history[state->cur_history] : "");
                        /* redraw and go to eol (bol, in vi) */
                        redraw(cmdedit_y, (state->flags & VI_MODE) ? 9999 : 0);
                        break;