liblinenoise/linenoise.c - platform/system/core - Git at Google

 /* 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
  *
  * 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>
  * 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.
  *   * Neither the name of Redis nor the names of its contributors may be used
  *     to endorse or promote products derived from this software without
  *     specific prior written permission.
  *
  * 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 OWNER 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.
  * - Win32 support
  *
  * 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
  *
  */

 #include <termios.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <unistd.h>

 #define LINENOISE_MAX_LINE 4096
 static char *unsupported_term[] = {"dumb","cons25",NULL};

 static struct termios orig_termios; /* in order to restore at exit */
 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 = 100;
 static int history_len = 0;
 char **history = NULL;

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

 static int isUnsupportedTerm(void) {
     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;
     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) {
     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 */
     if (tcsetattr(fd,TCSADRAIN,&raw) < 0) goto fatal;
     rawmode = 1;
     return 0;

 fatal:
     errno = ENOTTY;
     return -1;
 }

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

 /* At exit we'll try to fix the terminal to the initial conditions. */
 static void linenoiseAtExit(void) {
     disableRawMode(STDIN_FILENO);
     freeHistory();
 }

 static int getColumns(void) {
     struct winsize ws;

     if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 4096;
     if (ws.ws_col == 0) {
         return 4096;
     }
     return ws.ws_col;
 }

 static int effectiveLen(const char* prompt) {
     int col = 0;
     char c;
     // TODO: Handle escape sequences.
     while ( (c = *prompt++) != 0 ) {
         if (c == '\n') {
             col = 0;
         } else {
             col++;
         }
     }
     return col;
 }

 static void refreshLine(int fd, const char *prompt, char *buf, size_t len, size_t pos, size_t cols) {
     char seq[64];
     size_t plen = effectiveLen(prompt);

     while((plen+pos) >= cols) {
         buf++;
         len--;
         pos--;
     }
     while (plen+len > cols) {
         len--;
     }

     /* 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;
 }

 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;

     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("");

     if (write(fd,prompt,plen) == -1) return -1;
     while(1) {
         char c;
         int nread;
         char seq[2];

         nread = read(fd,&c,1);
         if (nread <= 0) return len;
         switch(c) {
         case 10:    /* line feed. */
         case 13:    /* enter */
             history_len--;
             return len;
         case 4:     /* ctrl-d */
             history_len--;
             return (len == 0) ? -1 : (int)len;
         case 3:     /* ctrl-c */
             errno = EAGAIN;
             return -1;
         case 127:   /* backspace */
         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 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);
                 }
             }
             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. */
                         if (write(fd,&c,1) == -1) return -1;
                     } 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;
         }
     }
     return 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, buflen, stdin) == NULL) return -1;
         count = 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);
     }
     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);
     }
 }

 /* 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 == 0) {
         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) {
         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 **new;

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

         new = malloc(sizeof(char*)*len);
         if (new == NULL) return 0;
         if (len < tocopy) tocopy = len;
         memcpy(new,history+(history_max_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;
 }
	/* 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
	*
	* 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>
	* 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.
	* * Neither the name of Redis nor the names of its contributors may be used
	* to endorse or promote products derived from this software without
	* specific prior written permission.
	*
	* 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 OWNER 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.
	* - Win32 support
	*
	* 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
	*
	*/

	#include <termios.h>
	#include <unistd.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <errno.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/ioctl.h>
	#include <unistd.h>

	#define LINENOISE_MAX_LINE 4096
	static char *unsupported_term[] = {"dumb","cons25",NULL};

	static struct termios orig_termios; /* in order to restore at exit */
	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 = 100;
	static int history_len = 0;
	char **history = NULL;

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

	static int isUnsupportedTerm(void) {
	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;
	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) {
	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 */
	if (tcsetattr(fd,TCSADRAIN,&raw) < 0) goto fatal;
	rawmode = 1;
	return 0;

	fatal:
	errno = ENOTTY;
	return -1;
	}

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

	/* At exit we'll try to fix the terminal to the initial conditions. */
	static void linenoiseAtExit(void) {
	disableRawMode(STDIN_FILENO);
	freeHistory();
	}

	static int getColumns(void) {
	struct winsize ws;

	if (ioctl(1, TIOCGWINSZ, &ws) == -1) return 4096;
	if (ws.ws_col == 0) {
	return 4096;
	}
	return ws.ws_col;
	}

	static int effectiveLen(const char* prompt) {
	int col = 0;
	char c;
	// TODO: Handle escape sequences.
	while ( (c = *prompt++) != 0 ) {
	if (c == '\n') {
	col = 0;
	} else {
	col++;
	}
	}
	return col;
	}

	static void refreshLine(int fd, const char prompt, char buf, size_t len, size_t pos, size_t cols) {
	char seq[64];
	size_t plen = effectiveLen(prompt);

	while((plen+pos) >= cols) {
	buf++;
	len--;
	pos--;
	}
	while (plen+len > cols) {
	len--;
	}

	/* 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;
	}

	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;

	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("");

	if (write(fd,prompt,plen) == -1) return -1;
	while(1) {
	char c;
	int nread;
	char seq[2];

	nread = read(fd,&c,1);
	if (nread <= 0) return len;
	switch(c) {
	case 10: /* line feed. */
	case 13: /* enter */
	history_len--;
	return len;
	case 4: /* ctrl-d */
	history_len--;
	return (len == 0) ? -1 : (int)len;
	case 3: /* ctrl-c */
	errno = EAGAIN;
	return -1;
	case 127: /* backspace */
	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 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);
	}
	}
	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. */
	if (write(fd,&c,1) == -1) return -1;
	} 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;
	}
	}
	return 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, buflen, stdin) == NULL) return -1;
	count = 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);
	}
	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);
	}
	}

	/* 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 == 0) {
	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) {
	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 **new;

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

	new = malloc(sizeof(char)len);
	if (new == NULL) return 0;
	if (len < tocopy) tocopy = len;
	memcpy(new,history+(history_max_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;
	}