mdebug

cortex m series debugger
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linenoise.c (38474B)


      1 /* linenoise.c -- VERSION 1.0
      2  *
      3  * Guerrilla line editing library against the idea that a line editing lib
      4  * needs to be 20,000 lines of C code.
      5  *
      6  * You can find the latest source code at:
      7  *
      8  *   http://github.com/antirez/linenoise
      9  *
     10  * Does a number of crazy assumptions that happen to be true in 99.9999% of
     11  * the 2010 UNIX computers around.
     12  *
     13  * ------------------------------------------------------------------------
     14  *
     15  * Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
     16  * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
     17  *
     18  * All rights reserved.
     19  *
     20  * Redistribution and use in source and binary forms, with or without
     21  * modification, are permitted provided that the following conditions are
     22  * met:
     23  *
     24  *  *  Redistributions of source code must retain the above copyright
     25  *     notice, this list of conditions and the following disclaimer.
     26  *
     27  *  *  Redistributions in binary form must reproduce the above copyright
     28  *     notice, this list of conditions and the following disclaimer in the
     29  *     documentation and/or other materials provided with the distribution.
     30  *
     31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     35  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     36  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     37  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     38  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     39  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     40  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     41  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     42  *
     43  * ------------------------------------------------------------------------
     44  *
     45  * References:
     46  * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
     47  * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
     48  *
     49  * Todo list:
     50  * - Filter bogus Ctrl+<char> combinations.
     51  * - Win32 support
     52  *
     53  * Bloat:
     54  * - History search like Ctrl+r in readline?
     55  *
     56  * List of escape sequences used by this program, we do everything just
     57  * with three sequences. In order to be so cheap we may have some
     58  * flickering effect with some slow terminal, but the lesser sequences
     59  * the more compatible.
     60  *
     61  * EL (Erase Line)
     62  *    Sequence: ESC [ n K
     63  *    Effect: if n is 0 or missing, clear from cursor to end of line
     64  *    Effect: if n is 1, clear from beginning of line to cursor
     65  *    Effect: if n is 2, clear entire line
     66  *
     67  * CUF (CUrsor Forward)
     68  *    Sequence: ESC [ n C
     69  *    Effect: moves cursor forward n chars
     70  *
     71  * CUB (CUrsor Backward)
     72  *    Sequence: ESC [ n D
     73  *    Effect: moves cursor backward n chars
     74  *
     75  * The following is used to get the terminal width if getting
     76  * the width with the TIOCGWINSZ ioctl fails
     77  *
     78  * DSR (Device Status Report)
     79  *    Sequence: ESC [ 6 n
     80  *    Effect: reports the current cusor position as ESC [ n ; m R
     81  *            where n is the row and m is the column
     82  *
     83  * When multi line mode is enabled, we also use an additional escape
     84  * sequence. However multi line editing is disabled by default.
     85  *
     86  * CUU (Cursor Up)
     87  *    Sequence: ESC [ n A
     88  *    Effect: moves cursor up of n chars.
     89  *
     90  * CUD (Cursor Down)
     91  *    Sequence: ESC [ n B
     92  *    Effect: moves cursor down of n chars.
     93  *
     94  * When linenoiseClearScreen() is called, two additional escape sequences
     95  * are used in order to clear the screen and position the cursor at home
     96  * position.
     97  *
     98  * CUP (Cursor position)
     99  *    Sequence: ESC [ H
    100  *    Effect: moves the cursor to upper left corner
    101  *
    102  * ED (Erase display)
    103  *    Sequence: ESC [ 2 J
    104  *    Effect: clear the whole screen
    105  *
    106  */
    107 
    108 #include <termios.h>
    109 #include <unistd.h>
    110 #include <stdlib.h>
    111 #include <stdio.h>
    112 #include <errno.h>
    113 #include <string.h>
    114 #include <stdlib.h>
    115 #include <ctype.h>
    116 #include <sys/types.h>
    117 #include <sys/ioctl.h>
    118 #include <unistd.h>
    119 #include "linenoise.h"
    120 
    121 #define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
    122 #define LINENOISE_MAX_LINE 4096
    123 static char *unsupported_term[] = {"dumb","cons25","emacs",NULL};
    124 static linenoiseCompletionCallback *completionCallback = NULL;
    125 
    126 static struct termios orig_termios; /* In order to restore at exit.*/
    127 static int rawmode = 0; /* For atexit() function to check if restore is needed*/
    128 static int mlmode = 0;  /* Multi line mode. Default is single line. */
    129 static int atexit_registered = 0; /* Register atexit just 1 time. */
    130 static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
    131 static int history_len = 0;
    132 static char **history = NULL;
    133 
    134 /* The linenoiseState structure represents the state during line editing.
    135  * We pass this state to functions implementing specific editing
    136  * functionalities. */
    137 struct linenoiseState {
    138     int ifd;            /* Terminal stdin file descriptor. */
    139     int ofd;            /* Terminal stdout file descriptor. */
    140     char *buf;          /* Edited line buffer. */
    141     size_t buflen;      /* Edited line buffer size. */
    142     const char *prompt; /* Prompt to display. */
    143     size_t plen;        /* Prompt length. */
    144     size_t pos;         /* Current cursor position. */
    145     size_t oldpos;      /* Previous refresh cursor position. */
    146     size_t len;         /* Current edited line length. */
    147     size_t cols;        /* Number of columns in terminal. */
    148     size_t maxrows;     /* Maximum num of rows used so far (multiline mode) */
    149     int history_index;  /* The history index we are currently editing. */
    150 };
    151 
    152 enum KEY_ACTION{
    153 	KEY_NULL = 0,	    /* NULL */
    154 	CTRL_A = 1,         /* Ctrl+a */
    155 	CTRL_B = 2,         /* Ctrl-b */
    156 	CTRL_C = 3,         /* Ctrl-c */
    157 	CTRL_D = 4,         /* Ctrl-d */
    158 	CTRL_E = 5,         /* Ctrl-e */
    159 	CTRL_F = 6,         /* Ctrl-f */
    160 	CTRL_H = 8,         /* Ctrl-h */
    161 	TAB = 9,            /* Tab */
    162 	CTRL_K = 11,        /* Ctrl+k */
    163 	CTRL_L = 12,        /* Ctrl+l */
    164 	ENTER = 13,         /* Enter */
    165 	CTRL_N = 14,        /* Ctrl-n */
    166 	CTRL_P = 16,        /* Ctrl-p */
    167 	CTRL_T = 20,        /* Ctrl-t */
    168 	CTRL_U = 21,        /* Ctrl+u */
    169 	CTRL_W = 23,        /* Ctrl+w */
    170 	ESC = 27,           /* Escape */
    171 	BACKSPACE =  127    /* Backspace */
    172 };
    173 
    174 static void linenoiseAtExit(void);
    175 int linenoiseHistoryAdd(const char *line);
    176 static void refreshLine(struct linenoiseState *l);
    177 
    178 /* Debugging macro. */
    179 #if 0
    180 FILE *lndebug_fp = NULL;
    181 #define lndebug(...) \
    182     do { \
    183         if (lndebug_fp == NULL) { \
    184             lndebug_fp = fopen("/tmp/lndebug.txt","a"); \
    185             fprintf(lndebug_fp, \
    186             "[%d %d %d] p: %d, rows: %d, rpos: %d, max: %d, oldmax: %d\n", \
    187             (int)l->len,(int)l->pos,(int)l->oldpos,plen,rows,rpos, \
    188             (int)l->maxrows,old_rows); \
    189         } \
    190         fprintf(lndebug_fp, ", " __VA_ARGS__); \
    191         fflush(lndebug_fp); \
    192     } while (0)
    193 #else
    194 #define lndebug(fmt, ...)
    195 #endif
    196 
    197 /* ======================= Low level terminal handling ====================== */
    198 
    199 /* Set if to use or not the multi line mode. */
    200 void linenoiseSetMultiLine(int ml) {
    201     mlmode = ml;
    202 }
    203 
    204 /* Return true if the terminal name is in the list of terminals we know are
    205  * not able to understand basic escape sequences. */
    206 static int isUnsupportedTerm(void) {
    207     char *term = getenv("TERM");
    208     int j;
    209 
    210     if (term == NULL) return 0;
    211     for (j = 0; unsupported_term[j]; j++)
    212         if (!strcasecmp(term,unsupported_term[j])) return 1;
    213     return 0;
    214 }
    215 
    216 /* Raw mode: 1960 magic shit. */
    217 static int enableRawMode(int fd) {
    218     struct termios raw;
    219 
    220     if (!isatty(STDIN_FILENO)) goto fatal;
    221     if (!atexit_registered) {
    222         atexit(linenoiseAtExit);
    223         atexit_registered = 1;
    224     }
    225     if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
    226 
    227     raw = orig_termios;  /* modify the original mode */
    228     /* input modes: no break, no CR to NL, no parity check, no strip char,
    229      * no start/stop output control. */
    230     raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
    231     /* output modes - disable post processing */
    232     raw.c_oflag &= ~(OPOST);
    233     /* control modes - set 8 bit chars */
    234     raw.c_cflag |= (CS8);
    235     /* local modes - choing off, canonical off, no extended functions,
    236      * no signal chars (^Z,^C) */
    237     raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
    238     /* control chars - set return condition: min number of bytes and timer.
    239      * We want read to return every single byte, without timeout. */
    240     raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
    241 
    242     /* put terminal in raw mode after flushing */
    243     if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
    244     rawmode = 1;
    245     return 0;
    246 
    247 fatal:
    248     errno = ENOTTY;
    249     return -1;
    250 }
    251 
    252 static void disableRawMode(int fd) {
    253     /* Don't even check the return value as it's too late. */
    254     if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
    255         rawmode = 0;
    256 }
    257 
    258 /* Use the ESC [6n escape sequence to query the horizontal cursor position
    259  * and return it. On error -1 is returned, on success the position of the
    260  * cursor. */
    261 static int getCursorPosition(int ifd, int ofd) {
    262     char buf[32];
    263     int cols, rows;
    264     unsigned int i = 0;
    265 
    266     /* Report cursor location */
    267     if (write(ofd, "\x1b[6n", 4) != 4) return -1;
    268 
    269     /* Read the response: ESC [ rows ; cols R */
    270     while (i < sizeof(buf)-1) {
    271         if (read(ifd,buf+i,1) != 1) break;
    272         if (buf[i] == 'R') break;
    273         i++;
    274     }
    275     buf[i] = '\0';
    276 
    277     /* Parse it. */
    278     if (buf[0] != ESC || buf[1] != '[') return -1;
    279     if (sscanf(buf+2,"%d;%d",&rows,&cols) != 2) return -1;
    280     return cols;
    281 }
    282 
    283 /* Try to get the number of columns in the current terminal, or assume 80
    284  * if it fails. */
    285 static int getColumns(int ifd, int ofd) {
    286     struct winsize ws;
    287 
    288     if (ioctl(1, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
    289         /* ioctl() failed. Try to query the terminal itself. */
    290         int start, cols;
    291 
    292         /* Get the initial position so we can restore it later. */
    293         start = getCursorPosition(ifd,ofd);
    294         if (start == -1) goto failed;
    295 
    296         /* Go to right margin and get position. */
    297         if (write(ofd,"\x1b[999C",6) != 6) goto failed;
    298         cols = getCursorPosition(ifd,ofd);
    299         if (cols == -1) goto failed;
    300 
    301         /* Restore position. */
    302         if (cols > start) {
    303             char seq[32];
    304             snprintf(seq,32,"\x1b[%dD",cols-start);
    305             if (write(ofd,seq,strlen(seq)) == -1) {
    306                 /* Can't recover... */
    307             }
    308         }
    309         return cols;
    310     } else {
    311         return ws.ws_col;
    312     }
    313 
    314 failed:
    315     return 80;
    316 }
    317 
    318 /* Clear the screen. Used to handle ctrl+l */
    319 void linenoiseClearScreen(void) {
    320     if (write(STDOUT_FILENO,"\x1b[H\x1b[2J",7) <= 0) {
    321         /* nothing to do, just to avoid warning. */
    322     }
    323 }
    324 
    325 /* Beep, used for completion when there is nothing to complete or when all
    326  * the choices were already shown. */
    327 static void linenoiseBeep(void) {
    328     fprintf(stderr, "\x7");
    329     fflush(stderr);
    330 }
    331 
    332 /* ============================== Completion ================================ */
    333 
    334 /* Free a list of completion option populated by linenoiseAddCompletion(). */
    335 static void freeCompletions(linenoiseCompletions *lc) {
    336     size_t i;
    337     for (i = 0; i < lc->len; i++)
    338         free(lc->cvec[i]);
    339     if (lc->cvec != NULL)
    340         free(lc->cvec);
    341 }
    342 
    343 /* This is an helper function for linenoiseEdit() and is called when the
    344  * user types the <tab> key in order to complete the string currently in the
    345  * input.
    346  *
    347  * The state of the editing is encapsulated into the pointed linenoiseState
    348  * structure as described in the structure definition. */
    349 static int completeLine(struct linenoiseState *ls) {
    350     linenoiseCompletions lc = { 0, NULL };
    351     int nread, nwritten;
    352     char c = 0;
    353 
    354     completionCallback(ls->buf,&lc);
    355     if (lc.len == 0) {
    356         linenoiseBeep();
    357     } else {
    358         size_t stop = 0, i = 0;
    359 
    360         while(!stop) {
    361             /* Show completion or original buffer */
    362             if (i < lc.len) {
    363                 struct linenoiseState saved = *ls;
    364 
    365                 ls->len = ls->pos = strlen(lc.cvec[i]);
    366                 ls->buf = lc.cvec[i];
    367                 refreshLine(ls);
    368                 ls->len = saved.len;
    369                 ls->pos = saved.pos;
    370                 ls->buf = saved.buf;
    371             } else {
    372                 refreshLine(ls);
    373             }
    374 
    375             nread = read(ls->ifd,&c,1);
    376             if (nread <= 0) {
    377                 freeCompletions(&lc);
    378                 return -1;
    379             }
    380 
    381             switch(c) {
    382                 case 9: /* tab */
    383                     i = (i+1) % (lc.len+1);
    384                     if (i == lc.len) linenoiseBeep();
    385                     break;
    386                 case 27: /* escape */
    387                     /* Re-show original buffer */
    388                     if (i < lc.len) refreshLine(ls);
    389                     stop = 1;
    390                     break;
    391                 default:
    392                     /* Update buffer and return */
    393                     if (i < lc.len) {
    394                         nwritten = snprintf(ls->buf,ls->buflen,"%s",lc.cvec[i]);
    395                         ls->len = ls->pos = nwritten;
    396                     }
    397                     stop = 1;
    398                     break;
    399             }
    400         }
    401     }
    402 
    403     freeCompletions(&lc);
    404     return c; /* Return last read character */
    405 }
    406 
    407 /* Register a callback function to be called for tab-completion. */
    408 void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
    409     completionCallback = fn;
    410 }
    411 
    412 /* This function is used by the callback function registered by the user
    413  * in order to add completion options given the input string when the
    414  * user typed <tab>. See the example.c source code for a very easy to
    415  * understand example. */
    416 void linenoiseAddCompletion(linenoiseCompletions *lc, const char *str) {
    417     size_t len = strlen(str);
    418     char *copy, **cvec;
    419 
    420     copy = malloc(len+1);
    421     if (copy == NULL) return;
    422     memcpy(copy,str,len+1);
    423     cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
    424     if (cvec == NULL) {
    425         free(copy);
    426         return;
    427     }
    428     lc->cvec = cvec;
    429     lc->cvec[lc->len++] = copy;
    430 }
    431 
    432 /* =========================== Line editing ================================= */
    433 
    434 /* We define a very simple "append buffer" structure, that is an heap
    435  * allocated string where we can append to. This is useful in order to
    436  * write all the escape sequences in a buffer and flush them to the standard
    437  * output in a single call, to avoid flickering effects. */
    438 struct abuf {
    439     char *b;
    440     int len;
    441 };
    442 
    443 static void abInit(struct abuf *ab) {
    444     ab->b = NULL;
    445     ab->len = 0;
    446 }
    447 
    448 static void abAppend(struct abuf *ab, const char *s, int len) {
    449     char *new = realloc(ab->b,ab->len+len);
    450 
    451     if (new == NULL) return;
    452     memcpy(new+ab->len,s,len);
    453     ab->b = new;
    454     ab->len += len;
    455 }
    456 
    457 static void abFree(struct abuf *ab) {
    458     free(ab->b);
    459 }
    460 
    461 /* Single line low level line refresh.
    462  *
    463  * Rewrite the currently edited line accordingly to the buffer content,
    464  * cursor position, and number of columns of the terminal. */
    465 static void refreshSingleLine(struct linenoiseState *l) {
    466     char seq[64];
    467     size_t plen = strlen(l->prompt);
    468     int fd = l->ofd;
    469     char *buf = l->buf;
    470     size_t len = l->len;
    471     size_t pos = l->pos;
    472     struct abuf ab;
    473 
    474     while((plen+pos) >= l->cols) {
    475         buf++;
    476         len--;
    477         pos--;
    478     }
    479     while (plen+len > l->cols) {
    480         len--;
    481     }
    482 
    483     abInit(&ab);
    484     /* Cursor to left edge */
    485     snprintf(seq,64,"\r");
    486     abAppend(&ab,seq,strlen(seq));
    487     /* Write the prompt and the current buffer content */
    488     abAppend(&ab,l->prompt,strlen(l->prompt));
    489     abAppend(&ab,buf,len);
    490     /* Erase to right */
    491     snprintf(seq,64,"\x1b[0K");
    492     abAppend(&ab,seq,strlen(seq));
    493     /* Move cursor to original position. */
    494     snprintf(seq,64,"\r\x1b[%dC", (int)(pos+plen));
    495     abAppend(&ab,seq,strlen(seq));
    496     if (write(fd,ab.b,ab.len) == -1) {} /* Can't recover from write error. */
    497     abFree(&ab);
    498 }
    499 
    500 /* Multi line low level line refresh.
    501  *
    502  * Rewrite the currently edited line accordingly to the buffer content,
    503  * cursor position, and number of columns of the terminal. */
    504 static void refreshMultiLine(struct linenoiseState *l) {
    505     char seq[64];
    506     int plen = strlen(l->prompt);
    507     int rows = (plen+l->len+l->cols-1)/l->cols; /* rows used by current buf. */
    508     int rpos = (plen+l->oldpos+l->cols)/l->cols; /* cursor relative row. */
    509     int rpos2; /* rpos after refresh. */
    510     int col; /* colum position, zero-based. */
    511     int old_rows = l->maxrows;
    512     int fd = l->ofd, j;
    513     struct abuf ab;
    514 
    515     /* Update maxrows if needed. */
    516     if (rows > (int)l->maxrows) l->maxrows = rows;
    517 
    518     /* First step: clear all the lines used before. To do so start by
    519      * going to the last row. */
    520     abInit(&ab);
    521     if (old_rows-rpos > 0) {
    522         lndebug("go down %d", old_rows-rpos);
    523         snprintf(seq,64,"\x1b[%dB", old_rows-rpos);
    524         abAppend(&ab,seq,strlen(seq));
    525     }
    526 
    527     /* Now for every row clear it, go up. */
    528     for (j = 0; j < old_rows-1; j++) {
    529         lndebug("clear+up");
    530         snprintf(seq,64,"\r\x1b[0K\x1b[1A");
    531         abAppend(&ab,seq,strlen(seq));
    532     }
    533 
    534     /* Clean the top line. */
    535     lndebug("clear");
    536     snprintf(seq,64,"\r\x1b[0K");
    537     abAppend(&ab,seq,strlen(seq));
    538 
    539     /* Write the prompt and the current buffer content */
    540     abAppend(&ab,l->prompt,strlen(l->prompt));
    541     abAppend(&ab,l->buf,l->len);
    542 
    543     /* If we are at the very end of the screen with our prompt, we need to
    544      * emit a newline and move the prompt to the first column. */
    545     if (l->pos &&
    546         l->pos == l->len &&
    547         (l->pos+plen) % l->cols == 0)
    548     {
    549         lndebug("<newline>");
    550         abAppend(&ab,"\n",1);
    551         snprintf(seq,64,"\r");
    552         abAppend(&ab,seq,strlen(seq));
    553         rows++;
    554         if (rows > (int)l->maxrows) l->maxrows = rows;
    555     }
    556 
    557     /* Move cursor to right position. */
    558     rpos2 = (plen+l->pos+l->cols)/l->cols; /* current cursor relative row. */
    559     lndebug("rpos2 %d", rpos2);
    560 
    561     /* Go up till we reach the expected positon. */
    562     if (rows-rpos2 > 0) {
    563         lndebug("go-up %d", rows-rpos2);
    564         snprintf(seq,64,"\x1b[%dA", rows-rpos2);
    565         abAppend(&ab,seq,strlen(seq));
    566     }
    567 
    568     /* Set column. */
    569     col = (plen+(int)l->pos) % (int)l->cols;
    570     lndebug("set col %d", 1+col);
    571     if (col)
    572         snprintf(seq,64,"\r\x1b[%dC", col);
    573     else
    574         snprintf(seq,64,"\r");
    575     abAppend(&ab,seq,strlen(seq));
    576 
    577     lndebug("\n");
    578     l->oldpos = l->pos;
    579 
    580     if (write(fd,ab.b,ab.len) == -1) {} /* Can't recover from write error. */
    581     abFree(&ab);
    582 }
    583 
    584 /* Calls the two low level functions refreshSingleLine() or
    585  * refreshMultiLine() according to the selected mode. */
    586 static void refreshLine(struct linenoiseState *l) {
    587     if (mlmode)
    588         refreshMultiLine(l);
    589     else
    590         refreshSingleLine(l);
    591 }
    592 
    593 /* Insert the character 'c' at cursor current position.
    594  *
    595  * On error writing to the terminal -1 is returned, otherwise 0. */
    596 int linenoiseEditInsert(struct linenoiseState *l, char c) {
    597     if (l->len < l->buflen) {
    598         if (l->len == l->pos) {
    599             l->buf[l->pos] = c;
    600             l->pos++;
    601             l->len++;
    602             l->buf[l->len] = '\0';
    603             if ((!mlmode && l->plen+l->len < l->cols) /* || mlmode */) {
    604                 /* Avoid a full update of the line in the
    605                  * trivial case. */
    606                 if (write(l->ofd,&c,1) == -1) return -1;
    607             } else {
    608                 refreshLine(l);
    609             }
    610         } else {
    611             memmove(l->buf+l->pos+1,l->buf+l->pos,l->len-l->pos);
    612             l->buf[l->pos] = c;
    613             l->len++;
    614             l->pos++;
    615             l->buf[l->len] = '\0';
    616             refreshLine(l);
    617         }
    618     }
    619     return 0;
    620 }
    621 
    622 /* Move cursor on the left. */
    623 void linenoiseEditMoveLeft(struct linenoiseState *l) {
    624     if (l->pos > 0) {
    625         l->pos--;
    626         refreshLine(l);
    627     }
    628 }
    629 
    630 /* Move cursor on the right. */
    631 void linenoiseEditMoveRight(struct linenoiseState *l) {
    632     if (l->pos != l->len) {
    633         l->pos++;
    634         refreshLine(l);
    635     }
    636 }
    637 
    638 /* Move cursor to the start of the line. */
    639 void linenoiseEditMoveHome(struct linenoiseState *l) {
    640     if (l->pos != 0) {
    641         l->pos = 0;
    642         refreshLine(l);
    643     }
    644 }
    645 
    646 /* Move cursor to the end of the line. */
    647 void linenoiseEditMoveEnd(struct linenoiseState *l) {
    648     if (l->pos != l->len) {
    649         l->pos = l->len;
    650         refreshLine(l);
    651     }
    652 }
    653 
    654 /* Substitute the currently edited line with the next or previous history
    655  * entry as specified by 'dir'. */
    656 #define LINENOISE_HISTORY_NEXT 0
    657 #define LINENOISE_HISTORY_PREV 1
    658 void linenoiseEditHistoryNext(struct linenoiseState *l, int dir) {
    659     if (history_len > 1) {
    660         /* Update the current history entry before to
    661          * overwrite it with the next one. */
    662         free(history[history_len - 1 - l->history_index]);
    663         history[history_len - 1 - l->history_index] = strdup(l->buf);
    664         /* Show the new entry */
    665         l->history_index += (dir == LINENOISE_HISTORY_PREV) ? 1 : -1;
    666         if (l->history_index < 0) {
    667             l->history_index = 0;
    668             return;
    669         } else if (l->history_index >= history_len) {
    670             l->history_index = history_len-1;
    671             return;
    672         }
    673         strncpy(l->buf,history[history_len - 1 - l->history_index],l->buflen);
    674         l->buf[l->buflen-1] = '\0';
    675         l->len = l->pos = strlen(l->buf);
    676         refreshLine(l);
    677     }
    678 }
    679 
    680 /* Delete the character at the right of the cursor without altering the cursor
    681  * position. Basically this is what happens with the "Delete" keyboard key. */
    682 void linenoiseEditDelete(struct linenoiseState *l) {
    683     if (l->len > 0 && l->pos < l->len) {
    684         memmove(l->buf+l->pos,l->buf+l->pos+1,l->len-l->pos-1);
    685         l->len--;
    686         l->buf[l->len] = '\0';
    687         refreshLine(l);
    688     }
    689 }
    690 
    691 /* Backspace implementation. */
    692 void linenoiseEditBackspace(struct linenoiseState *l) {
    693     if (l->pos > 0 && l->len > 0) {
    694         memmove(l->buf+l->pos-1,l->buf+l->pos,l->len-l->pos);
    695         l->pos--;
    696         l->len--;
    697         l->buf[l->len] = '\0';
    698         refreshLine(l);
    699     }
    700 }
    701 
    702 /* Delete the previosu word, maintaining the cursor at the start of the
    703  * current word. */
    704 void linenoiseEditDeletePrevWord(struct linenoiseState *l) {
    705     size_t old_pos = l->pos;
    706     size_t diff;
    707 
    708     while (l->pos > 0 && l->buf[l->pos-1] == ' ')
    709         l->pos--;
    710     while (l->pos > 0 && l->buf[l->pos-1] != ' ')
    711         l->pos--;
    712     diff = old_pos - l->pos;
    713     memmove(l->buf+l->pos,l->buf+old_pos,l->len-old_pos+1);
    714     l->len -= diff;
    715     refreshLine(l);
    716 }
    717 
    718 #ifndef LINENOISE_INTERRUPTIBLE
    719 #define linenoiseRead(l, buf, count) read((*(l)).ifd, buf, count)
    720 #define linenoiseLock() do {} while (0)
    721 #define linenoiseUnlock() do {} while (0)
    722 #else
    723 #include <pthread.h>
    724 #include <poll.h>
    725 
    726 static pthread_mutex_t linenoise_lock = PTHREAD_MUTEX_INITIALIZER;
    727 static int linenoise_active = 0;
    728 static int linenoise_repaint = 0;
    729 static int linenoise_pipefds[2] = { -1, -1 };
    730 
    731 /* allow linenoise to be interruptible */
    732 void linenoiseInit(void) {
    733     if (pipe(linenoise_pipefds) < 0) ;
    734 }
    735 
    736 /* Call before writing to stdout when linenoise may be active in
    737  * another thread.  This will suspend linenoise activity and 
    738  * clear the text entry line.  linenoiseResume() must be called
    739  * after your io is complete so that linenoise may continue.  */
    740 void linenoisePause(void) {
    741     pthread_mutex_lock(&linenoise_lock);
    742     if (linenoise_active) {
    743         if (write(1, "\x1b[0G\x1b[0K", 8) < 0) ;
    744         disableRawMode(STDIN_FILENO);
    745     }
    746 }
    747 
    748 /* Call when io is done after you've called linenoisePause()
    749  * to suspend linenoise processing during your io. */
    750 void linenoiseResume(void) {
    751     if (linenoise_active) {
    752         char x = 0;
    753         linenoise_repaint = 1;
    754         enableRawMode(STDIN_FILENO);
    755         if (write(linenoise_pipefds[1], &x, 1) < 0) ;
    756     }
    757     pthread_mutex_unlock(&linenoise_lock);
    758 }
    759 
    760 void linenoiseLock(void) {
    761     pthread_mutex_lock(&linenoise_lock);
    762     linenoise_active = 1;
    763 }
    764 
    765 void linenoiseUnlock(void) {
    766     linenoise_active = 0;
    767     pthread_mutex_unlock(&linenoise_lock);
    768 }
    769 
    770 ssize_t linenoiseRead(struct linenoiseState *l, void *ptr, int len) {
    771     struct pollfd fds[2];
    772     int nfds, r;
    773 
    774     for(;;) {
    775         fds[0].fd = l->ifd;
    776         fds[0].events = POLLIN;
    777         fds[0].revents = 0;
    778         fds[1].revents = 0;
    779         if (linenoise_pipefds[0] < 0) {
    780             nfds = 1;
    781         } else {
    782             fds[1].fd = linenoise_pipefds[0];
    783             fds[1].events = POLLIN;
    784             nfds = 2;
    785         }
    786 
    787         /* wait for input or refresh request */
    788         pthread_mutex_unlock(&linenoise_lock);
    789         r = poll(fds, nfds, -1);
    790         pthread_mutex_lock(&linenoise_lock);
    791 
    792         if (linenoise_repaint) {
    793             linenoise_repaint = 0;
    794             refreshLine(l);
    795         }
    796         if (r < 0) return -1;
    797         if (fds[1].revents & POLLIN) {
    798             char x;
    799             if (read(linenoise_pipefds[0], &x, 1) < 0) ;
    800             continue;
    801         }
    802         if (fds[0].revents & POLLIN) {
    803             return read(l->ifd, ptr, len);
    804         }
    805     }
    806 }
    807 #endif
    808 
    809 /* This function is the core of the line editing capability of linenoise.
    810  * It expects 'fd' to be already in "raw mode" so that every key pressed
    811  * will be returned ASAP to read().
    812  *
    813  * The resulting string is put into 'buf' when the user type enter, or
    814  * when ctrl+d is typed.
    815  *
    816  * The function returns the length of the current buffer. */
    817 static int linenoiseEdit(int stdin_fd, int stdout_fd, char *buf, size_t buflen, const char *prompt)
    818 {
    819     struct linenoiseState l;
    820 
    821     /* Populate the linenoise state that we pass to functions implementing
    822      * specific editing functionalities. */
    823     l.ifd = stdin_fd;
    824     l.ofd = stdout_fd;
    825     l.buf = buf;
    826     l.buflen = buflen;
    827     l.prompt = prompt;
    828     l.plen = strlen(prompt);
    829     l.oldpos = l.pos = 0;
    830     l.len = 0;
    831     l.cols = getColumns(stdin_fd, stdout_fd);
    832     l.maxrows = 0;
    833     l.history_index = 0;
    834 
    835     /* Buffer starts empty. */
    836     l.buf[0] = '\0';
    837     l.buflen--; /* Make sure there is always space for the nulterm */
    838 
    839     /* The latest history entry is always our current buffer, that
    840      * initially is just an empty string. */
    841     linenoiseHistoryAdd("");
    842 
    843     if (write(l.ofd,prompt,l.plen) == -1) return -1;
    844     while(1) {
    845         char c;
    846         int nread;
    847         char seq[3];
    848 
    849         nread = linenoiseRead(&l,&c,1);
    850         if (nread <= 0) return l.len;
    851 
    852         /* Only autocomplete when the callback is set. It returns < 0 when
    853          * there was an error reading from fd. Otherwise it will return the
    854          * character that should be handled next. */
    855         if (c == 9 && completionCallback != NULL) {
    856             c = completeLine(&l);
    857             /* Return on errors */
    858             if (c < 0) return l.len;
    859             /* Read next character when 0 */
    860             if (c == 0) continue;
    861         }
    862 
    863         switch(c) {
    864         case ENTER:    /* enter */
    865             history_len--;
    866             free(history[history_len]);
    867             if (mlmode) linenoiseEditMoveEnd(&l);
    868             return (int)l.len;
    869         case CTRL_C:     /* ctrl-c */
    870             errno = EAGAIN;
    871             return -1;
    872         case BACKSPACE:   /* backspace */
    873         case 8:     /* ctrl-h */
    874             linenoiseEditBackspace(&l);
    875             break;
    876         case CTRL_D:     /* ctrl-d, remove char at right of cursor, or if the
    877                             line is empty, act as end-of-file. */
    878             if (l.len > 0) {
    879                 linenoiseEditDelete(&l);
    880             } else {
    881                 history_len--;
    882                 free(history[history_len]);
    883                 return -1;
    884             }
    885             break;
    886         case CTRL_T:    /* ctrl-t, swaps current character with previous. */
    887             if (l.pos > 0 && l.pos < l.len) {
    888                 int aux = buf[l.pos-1];
    889                 buf[l.pos-1] = buf[l.pos];
    890                 buf[l.pos] = aux;
    891                 if (l.pos != l.len-1) l.pos++;
    892                 refreshLine(&l);
    893             }
    894             break;
    895         case CTRL_B:     /* ctrl-b */
    896             linenoiseEditMoveLeft(&l);
    897             break;
    898         case CTRL_F:     /* ctrl-f */
    899             linenoiseEditMoveRight(&l);
    900             break;
    901         case CTRL_P:    /* ctrl-p */
    902             linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV);
    903             break;
    904         case CTRL_N:    /* ctrl-n */
    905             linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT);
    906             break;
    907         case ESC:    /* escape sequence */
    908             /* Read the next two bytes representing the escape sequence.
    909              * Use two calls to handle slow terminals returning the two
    910              * chars at different times. */
    911             if (read(l.ifd,seq,1) == -1) break;
    912             if (read(l.ifd,seq+1,1) == -1) break;
    913 
    914             /* ESC [ sequences. */
    915             if (seq[0] == '[') {
    916                 if (seq[1] >= '0' && seq[1] <= '9') {
    917                     /* Extended escape, read additional byte. */
    918                     if (read(l.ifd,seq+2,1) == -1) break;
    919                     if (seq[2] == '~') {
    920                         switch(seq[1]) {
    921                         case '3': /* Delete key. */
    922                             linenoiseEditDelete(&l);
    923                             break;
    924                         }
    925                     }
    926                 } else {
    927                     switch(seq[1]) {
    928                     case 'A': /* Up */
    929                         linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV);
    930                         break;
    931                     case 'B': /* Down */
    932                         linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT);
    933                         break;
    934                     case 'C': /* Right */
    935                         linenoiseEditMoveRight(&l);
    936                         break;
    937                     case 'D': /* Left */
    938                         linenoiseEditMoveLeft(&l);
    939                         break;
    940                     case 'H': /* Home */
    941                         linenoiseEditMoveHome(&l);
    942                         break;
    943                     case 'F': /* End*/
    944                         linenoiseEditMoveEnd(&l);
    945                         break;
    946                     }
    947                 }
    948             }
    949 
    950             /* ESC O sequences. */
    951             else if (seq[0] == 'O') {
    952                 switch(seq[1]) {
    953                 case 'H': /* Home */
    954                     linenoiseEditMoveHome(&l);
    955                     break;
    956                 case 'F': /* End*/
    957                     linenoiseEditMoveEnd(&l);
    958                     break;
    959                 }
    960             }
    961             break;
    962         default:
    963             if (linenoiseEditInsert(&l,c)) return -1;
    964             break;
    965         case CTRL_U: /* Ctrl+u, delete the whole line. */
    966             buf[0] = '\0';
    967             l.pos = l.len = 0;
    968             refreshLine(&l);
    969             break;
    970         case CTRL_K: /* Ctrl+k, delete from current to end of line. */
    971             buf[l.pos] = '\0';
    972             l.len = l.pos;
    973             refreshLine(&l);
    974             break;
    975         case CTRL_A: /* Ctrl+a, go to the start of the line */
    976             linenoiseEditMoveHome(&l);
    977             break;
    978         case CTRL_E: /* ctrl+e, go to the end of the line */
    979             linenoiseEditMoveEnd(&l);
    980             break;
    981         case CTRL_L: /* ctrl+l, clear screen */
    982             linenoiseClearScreen();
    983             refreshLine(&l);
    984             break;
    985         case CTRL_W: /* ctrl+w, delete previous word */
    986             linenoiseEditDeletePrevWord(&l);
    987             break;
    988         }
    989     }
    990     return l.len;
    991 }
    992 
    993 /* This special mode is used by linenoise in order to print scan codes
    994  * on screen for debugging / development purposes. It is implemented
    995  * by the linenoise_example program using the --keycodes option. */
    996 void linenoisePrintKeyCodes(void) {
    997     char quit[4];
    998 
    999     printf("Linenoise key codes debugging mode.\n"
   1000             "Press keys to see scan codes. Type 'quit' at any time to exit.\n");
   1001     if (enableRawMode(STDIN_FILENO) == -1) return;
   1002     memset(quit,' ',4);
   1003     while(1) {
   1004         char c;
   1005         int nread;
   1006 
   1007         nread = read(STDIN_FILENO,&c,1);
   1008         if (nread <= 0) continue;
   1009         memmove(quit,quit+1,sizeof(quit)-1); /* shift string to left. */
   1010         quit[sizeof(quit)-1] = c; /* Insert current char on the right. */
   1011         if (memcmp(quit,"quit",sizeof(quit)) == 0) break;
   1012 
   1013         printf("'%c' %02x (%d) (type quit to exit)\n",
   1014             isprint(c) ? c : '?', (int)c, (int)c);
   1015         printf("\r"); /* Go left edge manually, we are in raw mode. */
   1016         fflush(stdout);
   1017     }
   1018     disableRawMode(STDIN_FILENO);
   1019 }
   1020 
   1021 /* This function calls the line editing function linenoiseEdit() using
   1022  * the STDIN file descriptor set in raw mode. */
   1023 static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
   1024     int count;
   1025 
   1026     if (buflen == 0) {
   1027         errno = EINVAL;
   1028         return -1;
   1029     }
   1030     if (!isatty(STDIN_FILENO)) {
   1031         /* Not a tty: read from file / pipe. */
   1032         if (fgets(buf, buflen, stdin) == NULL) return -1;
   1033         count = strlen(buf);
   1034         if (count && buf[count-1] == '\n') {
   1035             count--;
   1036             buf[count] = '\0';
   1037         }
   1038     } else {
   1039         /* Interactive editing. */
   1040         linenoiseLock();
   1041         if (enableRawMode(STDIN_FILENO) == -1) {
   1042             linenoiseUnlock();
   1043             return -1;
   1044         }
   1045         count = linenoiseEdit(STDIN_FILENO, STDOUT_FILENO, buf, buflen, prompt);
   1046         disableRawMode(STDIN_FILENO);
   1047         printf("\n");
   1048         linenoiseUnlock();
   1049     }
   1050     return count;
   1051 }
   1052 
   1053 /* The high level function that is the main API of the linenoise library.
   1054  * This function checks if the terminal has basic capabilities, just checking
   1055  * for a blacklist of stupid terminals, and later either calls the line
   1056  * editing function or uses dummy fgets() so that you will be able to type
   1057  * something even in the most desperate of the conditions. */
   1058 char *linenoise(const char *prompt) {
   1059     char buf[LINENOISE_MAX_LINE];
   1060     int count;
   1061 
   1062     if (isUnsupportedTerm()) {
   1063         size_t len;
   1064 
   1065         printf("%s",prompt);
   1066         fflush(stdout);
   1067         if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
   1068         len = strlen(buf);
   1069         while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
   1070             len--;
   1071             buf[len] = '\0';
   1072         }
   1073         return strdup(buf);
   1074     } else {
   1075         count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
   1076         if (count == -1) return NULL;
   1077         return strdup(buf);
   1078     }
   1079 }
   1080 
   1081 /* ================================ History ================================= */
   1082 
   1083 /* Free the history, but does not reset it. Only used when we have to
   1084  * exit() to avoid memory leaks are reported by valgrind & co. */
   1085 static void freeHistory(void) {
   1086     if (history) {
   1087         int j;
   1088 
   1089         for (j = 0; j < history_len; j++)
   1090             free(history[j]);
   1091         free(history);
   1092     }
   1093 }
   1094 
   1095 /* At exit we'll try to fix the terminal to the initial conditions. */
   1096 static void linenoiseAtExit(void) {
   1097     disableRawMode(STDIN_FILENO);
   1098     freeHistory();
   1099 }
   1100 
   1101 /* This is the API call to add a new entry in the linenoise history.
   1102  * It uses a fixed array of char pointers that are shifted (memmoved)
   1103  * when the history max length is reached in order to remove the older
   1104  * entry and make room for the new one, so it is not exactly suitable for huge
   1105  * histories, but will work well for a few hundred of entries.
   1106  *
   1107  * Using a circular buffer is smarter, but a bit more complex to handle. */
   1108 int linenoiseHistoryAdd(const char *line) {
   1109     char *linecopy;
   1110 
   1111     if (history_max_len == 0) return 0;
   1112 
   1113     /* Initialization on first call. */
   1114     if (history == NULL) {
   1115         history = malloc(sizeof(char*)*history_max_len);
   1116         if (history == NULL) return 0;
   1117         memset(history,0,(sizeof(char*)*history_max_len));
   1118     }
   1119 
   1120     /* Don't add duplicated lines. */
   1121     if (history_len && !strcmp(history[history_len-1], line)) return 0;
   1122 
   1123     /* Add an heap allocated copy of the line in the history.
   1124      * If we reached the max length, remove the older line. */
   1125     linecopy = strdup(line);
   1126     if (!linecopy) return 0;
   1127     if (history_len == history_max_len) {
   1128         free(history[0]);
   1129         memmove(history,history+1,sizeof(char*)*(history_max_len-1));
   1130         history_len--;
   1131     }
   1132     history[history_len] = linecopy;
   1133     history_len++;
   1134     return 1;
   1135 }
   1136 
   1137 /* Set the maximum length for the history. This function can be called even
   1138  * if there is already some history, the function will make sure to retain
   1139  * just the latest 'len' elements if the new history length value is smaller
   1140  * than the amount of items already inside the history. */
   1141 int linenoiseHistorySetMaxLen(int len) {
   1142     char **new;
   1143 
   1144     if (len < 1) return 0;
   1145     if (history) {
   1146         int tocopy = history_len;
   1147 
   1148         new = malloc(sizeof(char*)*len);
   1149         if (new == NULL) return 0;
   1150 
   1151         /* If we can't copy everything, free the elements we'll not use. */
   1152         if (len < tocopy) {
   1153             int j;
   1154 
   1155             for (j = 0; j < tocopy-len; j++) free(history[j]);
   1156             tocopy = len;
   1157         }
   1158         memset(new,0,sizeof(char*)*len);
   1159         memcpy(new,history+(history_len-tocopy), sizeof(char*)*tocopy);
   1160         free(history);
   1161         history = new;
   1162     }
   1163     history_max_len = len;
   1164     if (history_len > history_max_len)
   1165         history_len = history_max_len;
   1166     return 1;
   1167 }
   1168 
   1169 /* Save the history in the specified file. On success 0 is returned
   1170  * otherwise -1 is returned. */
   1171 int linenoiseHistorySave(const char *filename) {
   1172     FILE *fp = fopen(filename,"w");
   1173     int j;
   1174 
   1175     if (fp == NULL) return -1;
   1176     for (j = 0; j < history_len; j++)
   1177         fprintf(fp,"%s\n",history[j]);
   1178     fclose(fp);
   1179     return 0;
   1180 }
   1181 
   1182 /* Load the history from the specified file. If the file does not exist
   1183  * zero is returned and no operation is performed.
   1184  *
   1185  * If the file exists and the operation succeeded 0 is returned, otherwise
   1186  * on error -1 is returned. */
   1187 int linenoiseHistoryLoad(const char *filename) {
   1188     FILE *fp = fopen(filename,"r");
   1189     char buf[LINENOISE_MAX_LINE];
   1190 
   1191     if (fp == NULL) return -1;
   1192 
   1193     while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
   1194         char *p;
   1195 
   1196         p = strchr(buf,'\r');
   1197         if (!p) p = strchr(buf,'\n');
   1198         if (p) *p = '\0';
   1199         linenoiseHistoryAdd(buf);
   1200     }
   1201     fclose(fp);
   1202     return 0;
   1203 }