kc3-lang/linenoise/linenoise.c

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• Hash : 9a986552
  Author :
  Date : 2010-03-23T13:49:32
  

  now the API to add an history entry has a const argument

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• linenoise.c

• /* 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 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 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 after flushing */
      if (tcsetattr(fd,TCSAFLUSH,&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,TCSAFLUSH,&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 80;
      return ws.ws_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 = strlen(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 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 (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;
  
      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;
  }
  

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