root/lib/readline/linenoise.c

DEFINITIONS

1. win32read
2. strdup
3. isUnsupportedTerm
4. freeHistory
5. enableRawMode
6. disableRawMode
7. linenoiseAtExit
8. getColumns
9. refreshLine
10. beep
11. freeCompletions
12. completeLine
13. linenoiseClearScreen
14. linenoisePrompt
15. linenoiseRaw
16. linenoise
17. linenoiseSetCompletionCallback
18. linenoiseAddCompletion
19. linenoiseHistoryAdd
20. linenoiseHistorySetMaxLen
21. linenoiseHistorySave
22. linenoiseHistoryLoad

/* linenoise.c -- 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
 * and the win32 port at:
 *   http://github.com/Choonster/lua-linenoise-windows
 *
 * Does a number of crazy assumptions that happen to be true in 99.9999% of
 * the 2010 UNIX computers around.
 *
 * ------------------------------------------------------------------------
 *
 * Copyright (c) 2010, Salvatore Sanfilippo <antirez at gmail dot com>
 * Copyright (c) 2010, 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:
 * - Switch to gets() if $TERM is something we can't support.
 * - Filter bogus Ctrl+<char> combinations.
 *
 * Bloat:
 * - Completion?
 * - 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.
 *
 * CHA (Cursor Horizontal Absolute)
 *    Sequence: ESC [ n G
 *    Effect: moves cursor to column n
 *
 * 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 of n chars
 *
 * The following are used to clear the screen: ESC [ H ESC [ 2 J
 * This is actually composed of two sequences:
 *
 * cursorhome
 *    Sequence: ESC [ H
 *    Effect: moves the cursor to upper left corner
 *
 * ED2 (Clear entire screen)
 *    Sequence: ESC [ 2 J
 *    Effect: clear the whole screen
 * 
 */
#ifndef _WIN32
  #include <termios.h>
  #include <unistd.h>
  #include <sys/ioctl.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include "linenoise.h"
#define NOTUSED(V) ((void) V)
#ifdef _WIN32
  #include "win32fixes.h"
#endif

#define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
#define LINENOISE_MAX_LINE 4096
#ifndef _WIN32
static char *unsupported_term[] = {"dumb","cons25",NULL};
#endif
static linenoiseCompletionCallback *completionCallback = NULL;

#ifndef _WIN32
static struct termios orig_termios; /* in order to restore at exit */
#endif
static int rawmode = 0; /* for atexit() function to check if restore is needed*/
static int atexit_registered = 0; /* register atexit just 1 time */
static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
static int history_len = 0;
char **history = NULL;

static void linenoiseAtExit(void);
int linenoiseHistoryAdd(const char *line);

#ifdef _WIN32
#ifndef STDIN_FILENO
  #define STDIN_FILENO (_fileno(stdin))
#endif

HANDLE hOut;
HANDLE hIn;
DWORD consolemode;

static int win32read(char *c) {

    DWORD foo;
    INPUT_RECORD b;
    KEY_EVENT_RECORD e;

    while (1) {
        if (!ReadConsoleInput(hIn, &b, 1, &foo)) return 0;
        if (!foo) return 0;

        if (b.EventType == KEY_EVENT && b.Event.KeyEvent.bKeyDown) {

            e = b.Event.KeyEvent;
            *c = b.Event.KeyEvent.uChar.AsciiChar;

            //if (e.dwControlKeyState & (LEFT_ALT_PRESSED | RIGHT_ALT_PRESSED)) {
                /* Alt+key ignored */
            //} else
            if (e.dwControlKeyState & (LEFT_CTRL_PRESSED | RIGHT_CTRL_PRESSED)) {

                /* Ctrl+Key */
                switch (*c) {
                    case 'D':
                        *c = 4;
                        return 1;
                    case 'C':
                        *c = 3;
                        return 1;
                    case 'H':
                        *c = 8;
                        return 1;
                    case 'T':
                        *c = 20;
                        return 1;
                    case 'B': /* ctrl-b, left_arrow */
                        *c = 2;
                        return 1;
                    case 'F': /* ctrl-f right_arrow*/
                        *c = 6;
                        return 1;
                    case 'P': /* ctrl-p up_arrow*/
                        *c = 16;
                        return 1;
                    case 'N': /* ctrl-n down_arrow*/
                        *c = 14;
                        return 1;
                    case 'U': /* Ctrl+u, delete the whole line. */
                        *c = 21;
                        return 1;
                    case 'K': /* Ctrl+k, delete from current to end of line. */
                        *c = 11;
                        return 1;
                    case 'A': /* Ctrl+a, go to the start of the line */
                        *c = 1;
                        return 1;
                    case 'E': /* ctrl+e, go to the end of the line */
                        *c = 5;
                        return 1;
                }

                /* Other Ctrl+KEYs ignored */
            } else {

                switch (e.wVirtualKeyCode) {

                    case VK_ESCAPE: /* ignore - send ctrl-c, will return -1 */
                        *c = 3;
                        return 1;
                    case VK_RETURN:  /* enter */
                        *c = 13;
                        return 1;
                    case VK_LEFT:   /* left */
                        *c = 2;
                        return 1;
                    case VK_RIGHT: /* right */
                        *c = 6;
                        return 1;
                    case VK_UP:   /* up */
                        *c = 16;
                        return 1;
                    case VK_DOWN:  /* down */
                        *c = 14;
                        return 1;
                    case VK_HOME:
                        *c = 1;
                        return 1;
                    case VK_END:
                        *c = 5;
                        return 1;
                    case VK_BACK:
                        *c = 8;
                        return 1;
                    case VK_DELETE:
                        *c = 127;
                        return 1;
                    default:
                        if (*c) return 1;
                }
            }
        }
    }

    return -1; /* Makes compiler happy */
}

#ifdef __STRICT_ANSI__
char *strdup(const char *s) {
    size_t l = strlen(s)+1;
    char *p = malloc(l);

    memcpy(p,s,l);
    return p;
}
#endif /*   __STRICT_ANSI__   */

#endif /*   _WIN32    */

static int isUnsupportedTerm(void) {
#ifndef _WIN32
    char *term = getenv("TERM");
    int j;

    if (term == NULL) return 0;
    for (j = 0; unsupported_term[j]; j++)
        if (!strcasecmp(term,unsupported_term[j])) return 1;
#endif
    return 0;
}

static void freeHistory(void) {
    if (history) {
        int j;

        for (j = 0; j < history_len; j++)
            free(history[j]);
        free(history);
    }
}

static int enableRawMode(int fd) {
#ifndef _WIN32
    struct termios raw;

    if (!isatty(STDIN_FILENO)) goto fatal;
    if (!atexit_registered) {
        atexit(linenoiseAtExit);
        atexit_registered = 1;
    }
    if (tcgetattr(fd,&orig_termios) == -1) goto fatal;

    raw = orig_termios;  /* modify the original mode */
    /* input modes: no break, no CR to NL, no parity check, no strip char,
     * no start/stop output control. */
    raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
    /* output modes - disable post processing */
    raw.c_oflag &= ~(OPOST);
    /* control modes - set 8 bit chars */
    raw.c_cflag |= (CS8);
    /* local modes - choing off, canonical off, no extended functions,
     * no signal chars (^Z,^C) */
    raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
    /* control chars - set return condition: min number of bytes and timer.
     * We want read to return every single byte, without timeout. */
    raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */

    /* put terminal in raw mode after flushing */
    if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
    rawmode = 1;
#else
    NOTUSED(fd);

    if (!atexit_registered) {
        /* Init windows console handles only once */
        hOut = GetStdHandle(STD_OUTPUT_HANDLE);
        if (hOut==INVALID_HANDLE_VALUE) goto fatal;

        if (!GetConsoleMode(hOut, &consolemode)) {
            CloseHandle(hOut);
            errno = ENOTTY;
            return -1;
        };

        hIn = GetStdHandle(STD_INPUT_HANDLE);
        if (hIn == INVALID_HANDLE_VALUE) {
            CloseHandle(hOut);
            errno = ENOTTY;
            return -1;
        }

        GetConsoleMode(hIn, &consolemode);
        SetConsoleMode(hIn, ENABLE_PROCESSED_INPUT);

        /* Cleanup them at exit */
        atexit(linenoiseAtExit);
        atexit_registered = 1;
    }

    rawmode = 1;
#endif
    return 0;

fatal:
    errno = ENOTTY;
    return -1;
}

static void disableRawMode(int fd) {
#ifdef _WIN32
    NOTUSED(fd);
    rawmode = 0;
#else
    /* Don't even check the return value as it's too late. */
    if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
        rawmode = 0;
#endif
}

/* At exit we'll try to fix the terminal to the initial conditions. */
static void linenoiseAtExit(void) {
#ifdef _WIN32
    SetConsoleMode(hIn, consolemode);
    CloseHandle(hOut);
    CloseHandle(hIn);
#else
    disableRawMode(STDIN_FILENO);
#endif
    freeHistory();
}

static int getColumns(void) {
#ifdef _WIN32
    CONSOLE_SCREEN_BUFFER_INFO b;

    if (!GetConsoleScreenBufferInfo(hOut, &b)) return 80;
    return b.srWindow.Right - b.srWindow.Left;
#else
    struct winsize ws;

    if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 80;
    return ws.ws_col;
#endif
}

static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
    char seq[64];
#ifdef _WIN32
    DWORD pl, bl, w;
    CONSOLE_SCREEN_BUFFER_INFO b;
    COORD coord;
#endif
    size_t plen = strlen(prompt);
    
    while((plen+pos) >= cols) {
        buf++;
        len--;
        pos--;
    }
    while (plen+len > cols) {
        len--;
    }

#ifndef _WIN32
    /* Cursor to left edge */
    snprintf(seq,64,"\x1b[0G");
    if (write(fd,seq,strlen(seq)) == -1) return;
    /* Write the prompt and the current buffer content */
    if (write(fd,prompt,strlen(prompt)) == -1) return;
    if (write(fd,buf,len) == -1) return;
    /* Erase to right */
    snprintf(seq,64,"\x1b[0K");
    if (write(fd,seq,strlen(seq)) == -1) return;
    /* Move cursor to original position. */
    snprintf(seq,64,"\x1b[0G\x1b[%dC", (int)(pos+plen));
    if (write(fd,seq,strlen(seq)) == -1) return;
#else

    NOTUSED(seq);
    NOTUSED(fd);

    /* Get buffer console info */
    if (!GetConsoleScreenBufferInfo(hOut, &b)) return;
    /* Erase Line */
    coord.X = 0;
    coord.Y = b.dwCursorPosition.Y;
    FillConsoleOutputCharacterA(hOut, ' ', b.dwSize.X, coord, &w);
    /*  Cursor to the left edge */
    SetConsoleCursorPosition(hOut, coord);
    /* Write the prompt and the current buffer content */
    WriteConsole(hOut, prompt, (DWORD)plen, &pl, NULL);
    WriteConsole(hOut, buf, (DWORD)len, &bl, NULL);
    /* Move cursor to original position. */
    coord.X = (int)(pos+plen);
    coord.Y = b.dwCursorPosition.Y;
    SetConsoleCursorPosition(hOut, coord);
#endif
}

static void beep() {
    fprintf(stderr, "\x7");
    fflush(stderr);
}

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);
}

static int completeLine(int fd, const char *prompt, char *buf, size_t buflen, size_t *len, size_t *pos, size_t cols) {
    linenoiseCompletions lc = { 0, NULL };
    int nread, nwritten;
    char c = 0;

    completionCallback(buf,&lc);
    if (lc.len == 0) {
        beep();
    } else {
        size_t stop = 0, i = 0;
        size_t clen;

        while(!stop) {
            /* Show completion or original buffer */
            if (i < lc.len) {
                clen = strlen(lc.cvec[i]);
                refreshLine(fd,prompt,lc.cvec[i],clen,clen,cols);
            } else {
                refreshLine(fd,prompt,buf,*len,*pos,cols);
            }

            nread = read(fd,&c,1);
            if (nread <= 0) {
                freeCompletions(&lc);
                return -1;
            }

            switch(c) {
                case 9: /* tab */
                    i = (i+1) % (lc.len+1);
                    if (i == lc.len) beep();
                    break;
                case 27: /* escape */
                    /* Re-show original buffer */
                    if (i < lc.len) {
                        refreshLine(fd,prompt,buf,*len,*pos,cols);
                    }
                    stop = 1;
                    break;
                default:
                    /* Update buffer and return */
                    if (i < lc.len) {
                        nwritten = snprintf(buf,buflen,"%s",lc.cvec[i]);
                        *len = *pos = nwritten;
                    }
                    stop = 1;
                    break;
            }
        }
    }

    freeCompletions(&lc);
    return c; /* Return last read character */
}

void linenoiseClearScreen(void) {
    if (write(STDIN_FILENO,"\x1b[H\x1b[2J",7) <= 0) {
        /* nothing to do, just to avoid warning. */
    }
}

static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
    size_t plen = strlen(prompt);
    size_t pos = 0;
    size_t len = 0;
    size_t cols = getColumns();
    int history_index = 0;
#ifdef _WIN32
    DWORD foo;
#endif

    buf[0] = '\0';
    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("");
    
#ifdef _WIN32
    if (!WriteConsole(hOut, prompt, (DWORD)plen, &foo, NULL)) return -1;
#else
    if (write(fd,prompt,plen) == -1) return -1;
#endif
    while(1) {
        char c;
        int nread;
        char seq[2], seq2[2];

#ifdef _WIN32
        nread = win32read(&c);
#else
        nread = read(fd,&c,1);
#endif
        if (nread <= 0) return (int)len;

        /* 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(fd,prompt,buf,buflen,&len,&pos,cols);
            /* Return on errors */
            if (c < 0) return (int)len;
            /* Read next character when 0 */
            if (c == 0) continue;
        }

        switch(c) {
        case 13:    /* enter */
            history_len--;
            free(history[history_len]);
            return (int)len;
        case 3:     /* ctrl-c */
            errno = EAGAIN;
            return -1;
        case 127:   /* backspace */
#ifdef _WIN32
            /* delete in _WIN32*/
            /* win32read() will send 127 for DEL and 8 for BS and Ctrl-H */
            if (pos < len && len > 0) {
                memmove(buf+pos,buf+pos+1,len-pos);
                len--;
                buf[len] = '\0';
                refreshLine(fd,prompt,buf,len,pos,cols);
            }
            break;
#endif
        case 8:     /* ctrl-h */
            if (pos > 0 && len > 0) {
                memmove(buf+pos-1,buf+pos,len-pos);
                pos--;
                len--;
                buf[len] = '\0';
                refreshLine(fd,prompt,buf,len,pos,cols);
            }
            break;
        case 4:     /* ctrl-d, remove char at right of cursor */
            if (len > 1 && pos < (len-1)) {
                memmove(buf+pos,buf+pos+1,len-pos);
                len--;
                buf[len] = '\0';
                refreshLine(fd,prompt,buf,len,pos,cols);
            } else if (len == 0) {
                history_len--;
                free(history[history_len]);
                return -1;
            }
            break;
        case 20:    /* ctrl-t */
            if (pos > 0 && pos < len) {
                int aux = buf[pos-1];
                buf[pos-1] = buf[pos];
                buf[pos] = aux;
                if (pos != len-1) pos++;
                refreshLine(fd,prompt,buf,len,pos,cols);
            }
            break;
        case 2:     /* ctrl-b */
            goto left_arrow;
        case 6:     /* ctrl-f */
            goto right_arrow;
        case 16:    /* ctrl-p */
            seq[1] = 65;
            goto up_down_arrow;
        case 14:    /* ctrl-n */
            seq[1] = 66;
            goto up_down_arrow;
            break;
        case 27:    /* escape sequence */
            if (read(fd,seq,2) == -1) break;
            if (seq[0] == 91 && seq[1] == 68) {
left_arrow:
                /* left arrow */
                if (pos > 0) {
                    pos--;
                    refreshLine(fd,prompt,buf,len,pos,cols);
                }
            } else if (seq[0] == 91 && seq[1] == 67) {
right_arrow:
                /* right arrow */
                if (pos != len) {
                    pos++;
                    refreshLine(fd,prompt,buf,len,pos,cols);
                }
            } else if (seq[0] == 91 && (seq[1] == 65 || seq[1] == 66)) {
up_down_arrow:
                /* up and down arrow: history */
                if (history_len > 1) {
                    /* Update the current history entry before to
                     * overwrite it with tne next one. */
                    free(history[history_len-1-history_index]);
                    history[history_len-1-history_index] = strdup(buf);
                    /* Show the new entry */
                    history_index += (seq[1] == 65) ? 1 : -1;
                    if (history_index < 0) {
                        history_index = 0;
                        break;
                    } else if (history_index >= history_len) {
                        history_index = history_len-1;
                        break;
                    }
                    strncpy(buf,history[history_len-1-history_index],buflen);
                    buf[buflen] = '\0';
                    len = pos = strlen(buf);
                    refreshLine(fd,prompt,buf,len,pos,cols);
                }
            } else if (seq[0] == 91 && seq[1] > 48 && seq[1] < 55) {
                /* extended escape */
                if (read(fd,seq2,2) == -1) break;
                if (seq[1] == 51 && seq2[0] == 126) {
                    /* delete */
                    if (len > 0 && pos < len) {
                        memmove(buf+pos,buf+pos+1,len-pos-1);
                        len--;
                        buf[len] = '\0';
                        refreshLine(fd,prompt,buf,len,pos,cols);
                    }
                }
            }
            break;
        default:
            if (len < buflen) {
                if (len == pos) {
                    buf[pos] = c;
                    pos++;
                    len++;
                    buf[len] = '\0';
                    if (plen+len < cols) {
                        /* Avoid a full update of the line in the
                         * trivial case. */
#ifdef _WIN32
                        if (!WriteConsole(hOut, &c, 1, &foo, NULL)) return -1;
#else
                        if (write(fd,&c,1) == -1) return -1;
#endif
                    } else {
                        refreshLine(fd,prompt,buf,len,pos,cols);
                    }
                } else {
                    memmove(buf+pos+1,buf+pos,len-pos);
                    buf[pos] = c;
                    len++;
                    pos++;
                    buf[len] = '\0';
                    refreshLine(fd,prompt,buf,len,pos,cols);
                }
            }
            break;
        case 21: /* Ctrl+u, delete the whole line. */
            buf[0] = '\0';
            pos = len = 0;
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
        case 11: /* Ctrl+k, delete from current to end of line. */
            buf[pos] = '\0';
            len = pos;
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
        case 1: /* Ctrl+a, go to the start of the line */
            pos = 0;
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
        case 5: /* ctrl+e, go to the end of the line */
            pos = len;
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
        case 12: /* ctrl+l, clear screen */
            linenoiseClearScreen();
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
        case 23: /* ctrl+w, delete previous word */
          {
            size_t old_pos = pos;
            size_t diff;
            while (pos > 0 && buf[pos-1] == ' ')
                pos--;
            while (pos > 0 && buf[pos-1] != ' ')
                pos--;
            diff = old_pos - pos;
            memmove(&buf[pos], &buf[old_pos], len-old_pos+1);
            len -= diff;
            refreshLine(fd,prompt,buf,len,pos,cols);
            break;
          }
        }
    }
    return (int)len;
}

static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
    int fd = STDIN_FILENO;
    int count;

    if (buflen == 0) {
        errno = EINVAL;
        return -1;
    }
    if (!isatty(STDIN_FILENO)) {
        if (fgets(buf, (int)buflen, stdin) == NULL) return -1;
        count = (int)strlen(buf);
        if (count && buf[count-1] == '\n') {
            count--;
            buf[count] = '\0';
        }
    } else {
        if (enableRawMode(fd) == -1) return -1;
        count = linenoisePrompt(fd, buf, buflen, prompt);
        disableRawMode(fd);
        printf("\n");
    }
    return count;
}

char *linenoise(const char *prompt) {
    char buf[LINENOISE_MAX_LINE];
    int count;

    if (isUnsupportedTerm()) {
        size_t len;

        printf("%s",prompt);
        fflush(stdout);
        if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
        len = strlen(buf);
        while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
            len--;
            buf[len] = '\0';
        }
        return strdup(buf);
    } else {
        count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
        if (count == -1) return NULL;
        return strdup(buf);
    }
}

/* Register a callback function to be called for tab-completion. */
void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
    completionCallback = fn;
}

void linenoiseAddCompletion(linenoiseCompletions *lc, char *str) {
    size_t len = strlen(str);
    char *copy = malloc(len+1);
    memcpy(copy,str,len+1);
    lc->cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
    lc->cvec[lc->len++] = copy;
}

/* 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;
    if (history == NULL) {
        history = malloc(sizeof(char*)*history_max_len);
        if (history == NULL) return 0;
        memset(history,0,(sizeof(char*)*history_max_len));
    }
    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;
}

int linenoiseHistorySetMaxLen(int len) {
    char **newC;

    if (len < 1) return 0;
    if (history) {
        int tocopy = history_len;

        newC = malloc(sizeof(char*)*len);
        if (newC == NULL) return 0;
        if (len < tocopy) tocopy = len;
        memcpy(newC,history+(history_max_len-tocopy), sizeof(char*)*tocopy);
        free(history);
        history = newC;
    }
    history_max_len = len;
    if (history_len > history_max_len)
        history_len = history_max_len;
    return 1;
}

/* Save the history in the specified file. On success 0 is returned
 * otherwise -1 is returned. */
int linenoiseHistorySave(char *filename) {
#ifdef _WIN32
    FILE *fp = fopen(filename,"wb");
#else
    FILE *fp = fopen(filename,"w");
#endif
    int j;
    
    if (fp == NULL) return -1;
    for (j = 0; j < history_len; j++)
        fprintf(fp,"%s\n",history[j]);
    fclose(fp);
    return 0;
}

/* Load the history from the specified file. If the file does not exist
 * zero is returned and no operation is performed.
 *
 * If the file exists and the operation succeeded 0 is returned, otherwise
 * on error -1 is returned. */
int linenoiseHistoryLoad(char *filename) {
    FILE *fp = fopen(filename,"r");
    char buf[LINENOISE_MAX_LINE];
    
    if (fp == NULL) return -1;

    while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
        char *p;
        
        p = strchr(buf,'\r');
        if (!p) p = strchr(buf,'\n');
        if (p) *p = '\0';
        linenoiseHistoryAdd(buf);
    }
    fclose(fp);
    return 0;
}