/* linenoise.c -- VERSION 1.0 * * Guerrilla line editing library against the idea that a line editing lib * needs to be 20,000 lines of C code. * * You can find the latest source code at: * * http://github.com/antirez/linenoise * * Does a number of crazy assumptions that happen to be true in 99.9999% of * the 2010 UNIX computers around. * * ------------------------------------------------------------------------ * * Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com> * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com> * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * ------------------------------------------------------------------------ * * References: * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html * * Todo list: * - Filter bogus Ctrl+<char> combinations. * - Win32 support * * Bloat: * - History search like Ctrl+r in readline? * * List of escape sequences used by this program, we do everything just * with three sequences. In order to be so cheap we may have some * flickering effect with some slow terminal, but the lesser sequences * the more compatible. * * EL (Erase Line) * Sequence: ESC [ n K * Effect: if n is 0 or missing, clear from cursor to end of line * Effect: if n is 1, clear from beginning of line to cursor * Effect: if n is 2, clear entire line * * CUF (CUrsor Forward) * Sequence: ESC [ n C * Effect: moves cursor forward n chars * * CUB (CUrsor Backward) * Sequence: ESC [ n D * Effect: moves cursor backward n chars * * The following is used to get the terminal width if getting * the width with the TIOCGWINSZ ioctl fails * * DSR (Device Status Report) * Sequence: ESC [ 6 n * Effect: reports the current cusor position as ESC [ n ; m R * where n is the row and m is the column * * When multi line mode is enabled, we also use an additional escape * sequence. However multi line editing is disabled by default. * * CUU (Cursor Up) * Sequence: ESC [ n A * Effect: moves cursor up of n chars. * * CUD (Cursor Down) * Sequence: ESC [ n B * Effect: moves cursor down of n chars. * * When linenoiseClearScreen() is called, two additional escape sequences * are used in order to clear the screen and position the cursor at home * position. * * CUP (Cursor position) * Sequence: ESC [ H * Effect: moves the cursor to upper left corner * * ED (Erase display) * Sequence: ESC [ 2 J * Effect: clear the whole screen * */ #include <stand.h> #include "linenoise.h" #include "bootstrap.h" #define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100 #define LINENOISE_MAX_LINE 256 static linenoiseCompletionCallback *completionCallback = NULL; static int mlmode = 1; /* Multi line mode. Default is single line. */ static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN; static int history_len = 0; static char **history = NULL; /* The linenoiseState structure represents the state during line editing. * We pass this state to functions implementing specific editing * functionalities. */ struct linenoiseState { char *buf; /* Edited line buffer. */ size_t buflen; /* Edited line buffer size. */ const char *prompt; /* Prompt to display. */ size_t plen; /* Prompt length. */ size_t pos; /* Current cursor position. */ size_t oldpos; /* Previous refresh cursor position. */ size_t len; /* Current edited line length. */ size_t cols; /* Number of columns in terminal. */ size_t maxrows; /* Maximum num of rows used so far (multiline mode) */ int history_index; /* The history index we are currently editing. */ }; enum KEY_ACTION{ KEY_NULL = 0, /* NULL */ CTRL_A = 1, /* Ctrl+a */ CTRL_B = 2, /* Ctrl-b */ CTRL_C = 3, /* Ctrl-c */ CTRL_D = 4, /* Ctrl-d */ CTRL_E = 5, /* Ctrl-e */ CTRL_F = 6, /* Ctrl-f */ CTRL_H = 8, /* Ctrl-h */ TAB = 9, /* Tab */ CTRL_K = 11, /* Ctrl+k */ CTRL_L = 12, /* Ctrl+l */ ENTER = 13, /* Enter */ CTRL_N = 14, /* Ctrl-n */ CTRL_P = 16, /* Ctrl-p */ CTRL_T = 20, /* Ctrl-t */ CTRL_U = 21, /* Ctrl+u */ CTRL_W = 23, /* Ctrl+w */ ESC = 27, /* Escape */ BACKSPACE = 127 /* Backspace */ }; static void refreshLine(struct linenoiseState *l); /* ======================= Low level terminal handling ====================== */ static int put_bytes(const char *s, int len) { int i; if (s == NULL) return -1; for (i = 0; i < len; i++) putchar(s[i]); return (i); } /* Set if to use or not the multi line mode. */ void linenoiseSetMultiLine(int ml) { mlmode = ml; } /* Clear the screen. Used to handle ctrl+l */ void linenoiseClearScreen(void) { if (put_bytes("\x1b[H\x1b[J", 6) <= 0) { /* nothing to do, just to avoid warning. */ } } static int getColumns(void) { char *columns = getenv("screen-#cols"); if (columns == NULL) return (80); return (strtol(columns, NULL, 0)); } /* Beep, used for completion when there is nothing to complete or when all * the choices were already shown. */ static void linenoiseBeep(void) { put_bytes("\x7", 1); } /* ============================== Completion ================================ */ /* Free a list of completion option populated by linenoiseAddCompletion(). */ static void freeCompletions(linenoiseCompletions *lc) { size_t i; for (i = 0; i < lc->len; i++) free(lc->cvec[i]); if (lc->cvec != NULL) free(lc->cvec); } /* This is an helper function for linenoiseEdit() and is called when the * user types the <tab> key in order to complete the string currently in the * input. * * The state of the editing is encapsulated into the pointed linenoiseState * structure as described in the structure definition. */ static int completeLine(struct linenoiseState *ls) { linenoiseCompletions lc = { 0, NULL }; int nwritten; char c = 0; completionCallback(ls->buf,&lc); if (lc.len == 0) { linenoiseBeep(); } else { size_t stop = 0, i = 0; while(!stop) { /* Show completion or original buffer */ if (i < lc.len) { struct linenoiseState saved = *ls; ls->len = ls->pos = strlen(lc.cvec[i]); ls->buf = lc.cvec[i]; refreshLine(ls); ls->len = saved.len; ls->pos = saved.pos; ls->buf = saved.buf; } else { refreshLine(ls); } c = getchar(); if (c <= 0) { freeCompletions(&lc); return -1; } switch(c) { case 9: /* tab */ i = (i+1) % (lc.len+1); if (i == lc.len) linenoiseBeep(); break; case 27: /* escape */ /* Re-show original buffer */ if (i < lc.len) refreshLine(ls); stop = 1; break; default: /* Update buffer and return */ if (i < lc.len) { nwritten = snprintf(ls->buf,ls->buflen,"%s",lc.cvec[i]); ls->len = ls->pos = nwritten; } stop = 1; break; } } } freeCompletions(&lc); return c; /* Return last read character */ } /* Register a callback function to be called for tab-completion. */ void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) { completionCallback = fn; } /* This function is used by the callback function registered by the user * in order to add completion options given the input string when the * user typed <tab>. See the example.c source code for a very easy to * understand example. */ void linenoiseAddCompletion(linenoiseCompletions *lc, const char *str) { size_t len = strlen(str); char *copy, **cvec; copy = malloc(len+1); if (copy == NULL) return; memcpy(copy,str,len+1); cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1)); if (cvec == NULL) { free(copy); return; } lc->cvec = cvec; lc->cvec[lc->len++] = copy; } /* =========================== Line editing ================================= */ /* We define a very simple "append buffer" structure, that is an heap * allocated string where we can append to. This is useful in order to * write all the escape sequences in a buffer and flush them to the standard * output in a single call, to avoid flickering effects. */ struct abuf { char *b; int len; }; static void abInit(struct abuf *ab) { ab->b = NULL; ab->len = 0; } static void abAppend(struct abuf *ab, const char *s, int len) { char *new = malloc(ab->len+len); if (new == NULL) return; memcpy(new, ab->b, ab->len); memcpy(new+ab->len,s,len); free(ab->b); ab->b = new; ab->len += len; } static void abFree(struct abuf *ab) { free(ab->b); } /* Single line low level line refresh. * * Rewrite the currently edited line accordingly to the buffer content, * cursor position, and number of columns of the terminal. */ static void refreshSingleLine(struct linenoiseState *l) { char seq[64]; size_t plen = strlen(l->prompt); char *buf = l->buf; size_t len = l->len; size_t pos = l->pos; struct abuf ab; while((plen+pos) >= l->cols) { buf++; len--; pos--; } while (plen+len > l->cols) { len--; } abInit(&ab); /* Cursor to left edge */ snprintf(seq,64,"\r"); abAppend(&ab,seq,strlen(seq)); /* Write the prompt and the current buffer content */ abAppend(&ab,l->prompt,strlen(l->prompt)); abAppend(&ab,buf,len); /* Erase to right */ snprintf(seq,64,"\x1b[K"); abAppend(&ab,seq,strlen(seq)); /* Move cursor to original position. */ snprintf(seq,64,"\r\x1b[%dC", (int)(pos+plen)); abAppend(&ab,seq,strlen(seq)); put_bytes(ab.b, ab.len); abFree(&ab); } /* Multi line low level line refresh. * * Rewrite the currently edited line accordingly to the buffer content, * cursor position, and number of columns of the terminal. */ static void refreshMultiLine(struct linenoiseState *l) { char seq[64]; int plen = strlen(l->prompt); int rows = (plen+l->len+l->cols)/l->cols; /* rows used by current buf. */ int rpos = (plen+l->oldpos+l->cols)/l->cols; /* cursor relative row. */ int rpos2; /* rpos after refresh. */ int col; /* colum position, zero-based. */ int old_rows = l->maxrows; int j; struct abuf ab; /* Update maxrows if needed. */ if (rows > (int)l->maxrows) l->maxrows = rows; /* First step: clear all the lines used before. To do so start by * going to the last row. */ abInit(&ab); if (old_rows-rpos > 0) { snprintf(seq,64,"\x1b[%dB", old_rows-rpos); abAppend(&ab,seq,strlen(seq)); } /* Now for every row clear it, go up. */ for (j = 0; j < old_rows-1; j++) { snprintf(seq,64,"\r\x1b[0K\x1b[1A"); abAppend(&ab,seq,strlen(seq)); } /* Clean the top line. */ snprintf(seq,64,"\r\x1b[0K"); abAppend(&ab,seq,strlen(seq)); /* Write the prompt and the current buffer content */ abAppend(&ab,l->prompt,strlen(l->prompt)); abAppend(&ab,l->buf,l->len); /* If we are at the very end of the screen with our prompt, we need to * emit a newline and move the prompt to the first column. */ if (l->pos && l->pos == l->len && (l->pos+plen) % l->cols == 0) { abAppend(&ab,"\n",1); snprintf(seq,64,"\r"); abAppend(&ab,seq,strlen(seq)); rows++; if (rows > (int)l->maxrows) l->maxrows = rows; } /* Move cursor to right position. */ rpos2 = (plen+l->pos+l->cols)/l->cols; /* current cursor relative row. */ /* Go up till we reach the expected positon. */ if (rows-rpos2 > 0) { snprintf(seq,64,"\x1b[%dA", rows-rpos2); abAppend(&ab,seq,strlen(seq)); } /* Set column. */ col = (plen+(int)l->pos) % (int)l->cols; if (col) snprintf(seq,64,"\r\x1b[%dC", col); else snprintf(seq,64,"\r"); abAppend(&ab,seq,strlen(seq)); l->oldpos = l->pos; put_bytes(ab.b, ab.len); abFree(&ab); } /* Calls the two low level functions refreshSingleLine() or * refreshMultiLine() according to the selected mode. */ static void refreshLine(struct linenoiseState *l) { if (mlmode) refreshMultiLine(l); else refreshSingleLine(l); } /* Insert the character 'c' at cursor current position. * * On error writing to the terminal -1 is returned, otherwise 0. */ static int linenoiseEditInsert(struct linenoiseState *l, char c) { if (l->len < l->buflen) { if (l->len == l->pos) { l->buf[l->pos] = c; l->pos++; l->len++; l->buf[l->len] = '\0'; if ((!mlmode && l->plen+l->len < l->cols) /* || mlmode */) { /* Avoid a full update of the line in the * trivial case. */ putchar(c); } else { refreshLine(l); } } else { memmove(l->buf+l->pos+1,l->buf+l->pos,l->len-l->pos); l->buf[l->pos] = c; l->len++; l->pos++; l->buf[l->len] = '\0'; refreshLine(l); } } return 0; } /* Move cursor on the left. */ static void linenoiseEditMoveLeft(struct linenoiseState *l) { if (l->pos > 0) { l->pos--; refreshLine(l); } } /* Move cursor on the right. */ static void linenoiseEditMoveRight(struct linenoiseState *l) { if (l->pos != l->len) { l->pos++; refreshLine(l); } } /* Move cursor to the start of the line. */ static void linenoiseEditMoveHome(struct linenoiseState *l) { if (l->pos != 0) { l->pos = 0; refreshLine(l); } } /* Move cursor to the end of the line. */ static void linenoiseEditMoveEnd(struct linenoiseState *l) { if (l->pos != l->len) { l->pos = l->len; refreshLine(l); } } /* Substitute the currently edited line with the next or previous history * entry as specified by 'dir'. */ #define LINENOISE_HISTORY_NEXT 0 #define LINENOISE_HISTORY_PREV 1 static void linenoiseEditHistoryNext(struct linenoiseState *l, int dir) { if (history_len > 1) { /* Update the current history entry before to * overwrite it with the next one. */ free(history[history_len - 1 - l->history_index]); history[history_len - 1 - l->history_index] = strdup(l->buf); /* Show the new entry */ l->history_index += (dir == LINENOISE_HISTORY_PREV) ? 1 : -1; if (l->history_index < 0) { l->history_index = 0; return; } else if (l->history_index >= history_len) { l->history_index = history_len-1; return; } strncpy(l->buf,history[history_len - 1 - l->history_index],l->buflen); l->buf[l->buflen-1] = '\0'; l->len = l->pos = strlen(l->buf); refreshLine(l); } } /* Delete the character at the right of the cursor without altering the cursor * position. Basically this is what happens with the "Delete" keyboard key. */ static void linenoiseEditDelete(struct linenoiseState *l) { if (l->len > 0 && l->pos < l->len) { memmove(l->buf+l->pos,l->buf+l->pos+1,l->len-l->pos-1); l->len--; l->buf[l->len] = '\0'; refreshLine(l); } } /* Backspace implementation. */ static void linenoiseEditBackspace(struct linenoiseState *l) { if (l->pos > 0 && l->len > 0) { memmove(l->buf+l->pos-1,l->buf+l->pos,l->len-l->pos); l->pos--; l->len--; l->buf[l->len] = '\0'; refreshLine(l); } } /* Delete the previosu word, maintaining the cursor at the start of the * current word. */ static void linenoiseEditDeletePrevWord(struct linenoiseState *l) { size_t old_pos = l->pos; size_t diff; while (l->pos > 0 && l->buf[l->pos-1] == ' ') l->pos--; while (l->pos > 0 && l->buf[l->pos-1] != ' ') l->pos--; diff = old_pos - l->pos; memmove(l->buf+l->pos,l->buf+old_pos,l->len-old_pos+1); l->len -= diff; refreshLine(l); } /* This function is the core of the line editing capability of linenoise. * It expects 'fd' to be already in "raw mode" so that every key pressed * will be returned ASAP to read(). * * The resulting string is put into 'buf' when the user type enter, or * when ctrl+d is typed. * * The function returns the length of the current buffer. */ static int linenoiseEdit(char *buf, size_t buflen, const char *prompt) { struct linenoiseState l; /* Populate the linenoise state that we pass to functions implementing * specific editing functionalities. */ l.buf = buf; l.buflen = buflen; l.prompt = prompt; l.plen = strlen(prompt); l.oldpos = l.pos = 0; l.len = 0; l.cols = getColumns(); l.maxrows = 0; l.history_index = 0; /* Buffer starts empty. */ l.buf[0] = '\0'; l.buflen--; /* Make sure there is always space for the nulterm */ /* The latest history entry is always our current buffer, that * initially is just an empty string. */ linenoiseHistoryAdd(""); printf ("%s", prompt); while(1) { char c; char seq[3]; c = getchar(); if (c == -1) continue; /* Only autocomplete when the callback is set. It returns < 0 when * there was an error reading from fd. Otherwise it will return the * character that should be handled next. */ if (c == 9 && completionCallback != NULL) { c = completeLine(&l); /* Return on errors */ if (c < 0) return l.len; /* Read next character when 0 */ if (c == 0) continue; } switch(c) { case ENTER: /* enter */ history_len--; free(history[history_len]); if (mlmode) linenoiseEditMoveEnd(&l); return (int)l.len; case CTRL_C: /* ctrl-c */ buf[0] = '\0'; l.pos = l.len = 0; refreshLine(&l); break; case BACKSPACE: /* backspace */ case 8: /* ctrl-h */ linenoiseEditBackspace(&l); break; case CTRL_D: /* ctrl-d, remove char at right of cursor. */ if (l.len > 0) { linenoiseEditDelete(&l); } break; case CTRL_T: /* ctrl-t, swaps current character with previous. */ if (l.pos > 0 && l.pos < l.len) { int aux = buf[l.pos-1]; buf[l.pos-1] = buf[l.pos]; buf[l.pos] = aux; if (l.pos != l.len-1) l.pos++; refreshLine(&l); } break; case CTRL_B: /* ctrl-b */ linenoiseEditMoveLeft(&l); break; case CTRL_F: /* ctrl-f */ linenoiseEditMoveRight(&l); break; case CTRL_P: /* ctrl-p */ linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV); break; case CTRL_N: /* ctrl-n */ linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT); break; case ESC: /* escape sequence */ /* Read the next two bytes representing the escape sequence. * Use two calls to handle slow terminals returning the two * chars at different times. */ seq[0] = getchar(); seq[1] = getchar(); /* ESC [ sequences. */ if (seq[0] == '[') { if (seq[1] >= '0' && seq[1] <= '9') { /* Extended escape, read additional byte. */ seq[2] = getchar(); if (seq[2] == '~') { switch(seq[1]) { case '3': /* Delete key. */ linenoiseEditDelete(&l); break; } } } else { switch(seq[1]) { case 'A': /* Up */ linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV); break; case 'B': /* Down */ linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT); break; case 'C': /* Right */ linenoiseEditMoveRight(&l); break; case 'D': /* Left */ linenoiseEditMoveLeft(&l); break; case 'H': /* Home */ linenoiseEditMoveHome(&l); break; case 'F': /* End*/ linenoiseEditMoveEnd(&l); break; } } } /* ESC O sequences. */ else if (seq[0] == 'O') { switch(seq[1]) { case 'H': /* Home */ linenoiseEditMoveHome(&l); break; case 'F': /* End*/ linenoiseEditMoveEnd(&l); break; } } break; default: if (linenoiseEditInsert(&l,c)) return -1; break; case CTRL_U: /* Ctrl+u, delete the whole line. */ buf[0] = '\0'; l.pos = l.len = 0; refreshLine(&l); break; case CTRL_K: /* Ctrl+k, delete from current to end of line. */ buf[l.pos] = '\0'; l.len = l.pos; refreshLine(&l); break; case CTRL_A: /* Ctrl+a, go to the start of the line */ linenoiseEditMoveHome(&l); break; case CTRL_E: /* ctrl+e, go to the end of the line */ linenoiseEditMoveEnd(&l); break; case CTRL_L: /* ctrl+l, clear screen */ linenoiseClearScreen(); refreshLine(&l); break; case CTRL_W: /* ctrl+w, delete previous word */ linenoiseEditDeletePrevWord(&l); break; } } return l.len; } /* The high level function that is the main API of the linenoise library. * This function checks if the terminal has basic capabilities, just checking * for a blacklist of stupid terminals, and later either calls the line * editing function or uses dummy fgets() so that you will be able to type * something even in the most desperate of the conditions. */ char *linenoise(const char *prompt) { char buf[LINENOISE_MAX_LINE]; int count; cons_mode(C_MODERAW); count = linenoiseEdit(buf,LINENOISE_MAX_LINE,prompt); cons_mode(0); printf("\n"); if (count == -1) return NULL; return strdup(buf); } /* ================================ History ================================= */ /* This is the API call to add a new entry in the linenoise history. * It uses a fixed array of char pointers that are shifted (memmoved) * when the history max length is reached in order to remove the older * entry and make room for the new one, so it is not exactly suitable for huge * histories, but will work well for a few hundred of entries. * * Using a circular buffer is smarter, but a bit more complex to handle. */ int linenoiseHistoryAdd(const char *line) { char *linecopy; if (history_max_len == 0) return 0; /* Initialization on first call. */ if (history == NULL) { history = malloc(sizeof(char*)*history_max_len); if (history == NULL) return 0; memset(history,0,(sizeof(char*)*history_max_len)); } /* Don't add duplicated lines. */ if (history_len && !strcmp(history[history_len-1], line)) return 0; /* Add an heap allocated copy of the line in the history. * If we reached the max length, remove the older line. */ linecopy = strdup(line); if (!linecopy) return 0; if (history_len == history_max_len) { free(history[0]); memmove(history,history+1,sizeof(char*)*(history_max_len-1)); history_len--; } history[history_len] = linecopy; history_len++; return 1; } /* Set the maximum length for the history. This function can be called even * if there is already some history, the function will make sure to retain * just the latest 'len' elements if the new history length value is smaller * than the amount of items already inside the history. */ int linenoiseHistorySetMaxLen(int len) { char **new; if (len < 1) return 0; if (history) { int tocopy = history_len; new = malloc(sizeof(char*)*len); if (new == NULL) return 0; /* If we can't copy everything, free the elements we'll not use. */ if (len < tocopy) { int j; for (j = 0; j < tocopy-len; j++) free(history[j]); tocopy = len; } memset(new,0,sizeof(char*)*len); memcpy(new,history+(history_len-tocopy), sizeof(char*)*tocopy); free(history); history = new; } history_max_len = len; if (history_len > history_max_len) history_len = history_max_len; return 1; }
