]> git.cworth.org Git - apitrace/blobdiff - thirdparty/less/cmdbuf.c
Bundle less (version 444) for Windows.
[apitrace] / thirdparty / less / cmdbuf.c
diff --git a/thirdparty/less/cmdbuf.c b/thirdparty/less/cmdbuf.c
new file mode 100644 (file)
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--- /dev/null
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+/*
+ * Copyright (C) 1984-2011  Mark Nudelman
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Less License, as specified in the README file.
+ *
+ * For more information about less, or for information on how to 
+ * contact the author, see the README file.
+ */
+
+
+/*
+ * Functions which manipulate the command buffer.
+ * Used only by command() and related functions.
+ */
+
+#include "less.h"
+#include "cmd.h"
+#include "charset.h"
+#if HAVE_STAT
+#include <sys/stat.h>
+#endif
+
+extern int sc_width;
+extern int utf_mode;
+
+static char cmdbuf[CMDBUF_SIZE]; /* Buffer for holding a multi-char command */
+static int cmd_col;            /* Current column of the cursor */
+static int prompt_col;         /* Column of cursor just after prompt */
+static char *cp;               /* Pointer into cmdbuf */
+static int cmd_offset;         /* Index into cmdbuf of first displayed char */
+static int literal;            /* Next input char should not be interpreted */
+
+#if TAB_COMPLETE_FILENAME
+static int cmd_complete();
+/*
+ * These variables are statics used by cmd_complete.
+ */
+static int in_completion = 0;
+static char *tk_text;
+static char *tk_original;
+static char *tk_ipoint;
+static char *tk_trial;
+static struct textlist tk_tlist;
+#endif
+
+static int cmd_left();
+static int cmd_right();
+
+#if SPACES_IN_FILENAMES
+public char openquote = '"';
+public char closequote = '"';
+#endif
+
+#if CMD_HISTORY
+
+/* History file */
+#define HISTFILE_FIRST_LINE      ".less-history-file:"
+#define HISTFILE_SEARCH_SECTION  ".search"
+#define HISTFILE_SHELL_SECTION   ".shell"
+
+/*
+ * A mlist structure represents a command history.
+ */
+struct mlist
+{
+       struct mlist *next;
+       struct mlist *prev;
+       struct mlist *curr_mp;
+       char *string;
+       int modified;
+};
+
+/*
+ * These are the various command histories that exist.
+ */
+struct mlist mlist_search =  
+       { &mlist_search,  &mlist_search,  &mlist_search,  NULL, 0 };
+public void * constant ml_search = (void *) &mlist_search;
+
+struct mlist mlist_examine = 
+       { &mlist_examine, &mlist_examine, &mlist_examine, NULL, 0 };
+public void * constant ml_examine = (void *) &mlist_examine;
+
+#if SHELL_ESCAPE || PIPEC
+struct mlist mlist_shell =   
+       { &mlist_shell,   &mlist_shell,   &mlist_shell,   NULL, 0 };
+public void * constant ml_shell = (void *) &mlist_shell;
+#endif
+
+#else /* CMD_HISTORY */
+
+/* If CMD_HISTORY is off, these are just flags. */
+public void * constant ml_search = (void *)1;
+public void * constant ml_examine = (void *)2;
+#if SHELL_ESCAPE || PIPEC
+public void * constant ml_shell = (void *)3;
+#endif
+
+#endif /* CMD_HISTORY */
+
+/*
+ * History for the current command.
+ */
+static struct mlist *curr_mlist = NULL;
+static int curr_cmdflags;
+
+static char cmd_mbc_buf[MAX_UTF_CHAR_LEN];
+static int cmd_mbc_buf_len;
+static int cmd_mbc_buf_index;
+
+
+/*
+ * Reset command buffer (to empty).
+ */
+       public void
+cmd_reset()
+{
+       cp = cmdbuf;
+       *cp = '\0';
+       cmd_col = 0;
+       cmd_offset = 0;
+       literal = 0;
+       cmd_mbc_buf_len = 0;
+}
+
+/*
+ * Clear command line.
+ */
+       public void
+clear_cmd()
+{
+       cmd_col = prompt_col = 0;
+       cmd_mbc_buf_len = 0;
+}
+
+/*
+ * Display a string, usually as a prompt for input into the command buffer.
+ */
+       public void
+cmd_putstr(s)
+       char *s;
+{
+       LWCHAR prev_ch = 0;
+       LWCHAR ch;
+       char *endline = s + strlen(s);
+       while (*s != '\0')
+       {
+               char *ns = s;
+               ch = step_char(&ns, +1, endline);
+               while (s < ns)
+                       putchr(*s++);
+               if (!utf_mode)
+               {
+                       cmd_col++;
+                       prompt_col++;
+               } else if (!is_composing_char(ch) &&
+                          !is_combining_char(prev_ch, ch))
+               {
+                       int width = is_wide_char(ch) ? 2 : 1;
+                       cmd_col += width;
+                       prompt_col += width;
+               }
+               prev_ch = ch;
+       }
+}
+
+/*
+ * How many characters are in the command buffer?
+ */
+       public int
+len_cmdbuf()
+{
+       char *s = cmdbuf;
+       char *endline = s + strlen(s);
+       int len = 0;
+
+       while (*s != '\0')
+       {
+               step_char(&s, +1, endline);
+               len++;
+       }
+       return (len);
+}
+
+/*
+ * Common part of cmd_step_right() and cmd_step_left().
+ */
+       static char *
+cmd_step_common(p, ch, len, pwidth, bswidth)
+       char *p;
+       LWCHAR ch;
+       int len;
+       int *pwidth;
+       int *bswidth;
+{
+       char *pr;
+
+       if (len == 1)
+       {
+               pr = prchar((int) ch);
+               if (pwidth != NULL || bswidth != NULL)
+               {
+                       int len = strlen(pr);
+                       if (pwidth != NULL)
+                               *pwidth = len;
+                       if (bswidth != NULL)
+                               *bswidth = len;
+               }
+       } else
+       {
+               pr = prutfchar(ch);
+               if (pwidth != NULL || bswidth != NULL)
+               {
+                       if (is_composing_char(ch))
+                       {
+                               if (pwidth != NULL)
+                                       *pwidth = 0;
+                               if (bswidth != NULL)
+                                       *bswidth = 0;
+                       } else if (is_ubin_char(ch))
+                       {
+                               int len = strlen(pr);
+                               if (pwidth != NULL)
+                                       *pwidth = len;
+                               if (bswidth != NULL)
+                                       *bswidth = len;
+                       } else
+                       {
+                               LWCHAR prev_ch = step_char(&p, -1, cmdbuf);
+                               if (is_combining_char(prev_ch, ch))
+                               {
+                                       if (pwidth != NULL)
+                                               *pwidth = 0;
+                                       if (bswidth != NULL)
+                                               *bswidth = 0;
+                               } else
+                               {
+                                       if (pwidth != NULL)
+                                               *pwidth = is_wide_char(ch)
+                                                       ?       2
+                                                       :       1;
+                                       if (bswidth != NULL)
+                                               *bswidth = 1;
+                               }
+                       }
+               }
+       }
+
+       return (pr);
+}
+
+/*
+ * Step a pointer one character right in the command buffer.
+ */
+       static char *
+cmd_step_right(pp, pwidth, bswidth)
+       char **pp;
+       int *pwidth;
+       int *bswidth;
+{
+       char *p = *pp;
+       LWCHAR ch = step_char(pp, +1, p + strlen(p));
+
+       return cmd_step_common(p, ch, *pp - p, pwidth, bswidth);
+}
+
+/*
+ * Step a pointer one character left in the command buffer.
+ */
+       static char *
+cmd_step_left(pp, pwidth, bswidth)
+       char **pp;
+       int *pwidth;
+       int *bswidth;
+{
+       char *p = *pp;
+       LWCHAR ch = step_char(pp, -1, cmdbuf);
+
+       return cmd_step_common(*pp, ch, p - *pp, pwidth, bswidth);
+}
+
+/*
+ * Repaint the line from cp onwards.
+ * Then position the cursor just after the char old_cp (a pointer into cmdbuf).
+ */
+       static void
+cmd_repaint(old_cp)
+       char *old_cp;
+{
+       /*
+        * Repaint the line from the current position.
+        */
+       clear_eol();
+       while (*cp != '\0')
+       {
+               char *np = cp;
+               int width;
+               char *pr = cmd_step_right(&np, &width, NULL);
+               if (cmd_col + width >= sc_width)
+                       break;
+               cp = np;
+               putstr(pr);
+               cmd_col += width;
+       }
+       while (*cp != '\0')
+       {
+               char *np = cp;
+               int width;
+               char *pr = cmd_step_right(&np, &width, NULL);
+               if (width > 0)
+                       break;
+               cp = np;
+               putstr(pr);
+       }
+
+       /*
+        * Back up the cursor to the correct position.
+        */
+       while (cp > old_cp)
+               cmd_left();
+}
+
+/*
+ * Put the cursor at "home" (just after the prompt),
+ * and set cp to the corresponding char in cmdbuf.
+ */
+       static void
+cmd_home()
+{
+       while (cmd_col > prompt_col)
+       {
+               int width, bswidth;
+
+               cmd_step_left(&cp, &width, &bswidth);
+               while (bswidth-- > 0)
+                       putbs();
+               cmd_col -= width;
+       }
+
+       cp = &cmdbuf[cmd_offset];
+}
+
+/*
+ * Shift the cmdbuf display left a half-screen.
+ */
+       static void
+cmd_lshift()
+{
+       char *s;
+       char *save_cp;
+       int cols;
+
+       /*
+        * Start at the first displayed char, count how far to the
+        * right we'd have to move to reach the center of the screen.
+        */
+       s = cmdbuf + cmd_offset;
+       cols = 0;
+       while (cols < (sc_width - prompt_col) / 2 && *s != '\0')
+       {
+               int width;
+               cmd_step_right(&s, &width, NULL);
+               cols += width;
+       }
+       while (*s != '\0')
+       {
+               int width;
+               char *ns = s;
+               cmd_step_right(&ns, &width, NULL);
+               if (width > 0)
+                       break;
+               s = ns;
+       }
+
+       cmd_offset = s - cmdbuf;
+       save_cp = cp;
+       cmd_home();
+       cmd_repaint(save_cp);
+}
+
+/*
+ * Shift the cmdbuf display right a half-screen.
+ */
+       static void
+cmd_rshift()
+{
+       char *s;
+       char *save_cp;
+       int cols;
+
+       /*
+        * Start at the first displayed char, count how far to the
+        * left we'd have to move to traverse a half-screen width
+        * of displayed characters.
+        */
+       s = cmdbuf + cmd_offset;
+       cols = 0;
+       while (cols < (sc_width - prompt_col) / 2 && s > cmdbuf)
+       {
+               int width;
+               cmd_step_left(&s, &width, NULL);
+               cols += width;
+       }
+
+       cmd_offset = s - cmdbuf;
+       save_cp = cp;
+       cmd_home();
+       cmd_repaint(save_cp);
+}
+
+/*
+ * Move cursor right one character.
+ */
+       static int
+cmd_right()
+{
+       char *pr;
+       char *ncp;
+       int width;
+       
+       if (*cp == '\0')
+       {
+               /* Already at the end of the line. */
+               return (CC_OK);
+       }
+       ncp = cp;
+       pr = cmd_step_right(&ncp, &width, NULL);
+       if (cmd_col + width >= sc_width)
+               cmd_lshift();
+       else if (cmd_col + width == sc_width - 1 && cp[1] != '\0')
+               cmd_lshift();
+       cp = ncp;
+       cmd_col += width;
+       putstr(pr);
+       while (*cp != '\0')
+       {
+               pr = cmd_step_right(&ncp, &width, NULL);
+               if (width > 0)
+                       break;
+               putstr(pr);
+               cp = ncp;
+       }
+       return (CC_OK);
+}
+
+/*
+ * Move cursor left one character.
+ */
+       static int
+cmd_left()
+{
+       char *ncp;
+       int width, bswidth;
+       
+       if (cp <= cmdbuf)
+       {
+               /* Already at the beginning of the line */
+               return (CC_OK);
+       }
+       ncp = cp;
+       while (ncp > cmdbuf)
+       {
+               cmd_step_left(&ncp, &width, &bswidth);
+               if (width > 0)
+                       break;
+       }
+       if (cmd_col < prompt_col + width)
+               cmd_rshift();
+       cp = ncp;
+       cmd_col -= width;
+       while (bswidth-- > 0)
+               putbs();
+       return (CC_OK);
+}
+
+/*
+ * Insert a char into the command buffer, at the current position.
+ */
+       static int
+cmd_ichar(cs, clen)
+       char *cs;
+       int clen;
+{
+       char *s;
+       
+       if (strlen(cmdbuf) + clen >= sizeof(cmdbuf)-1)
+       {
+               /* No room in the command buffer for another char. */
+               bell();
+               return (CC_ERROR);
+       }
+               
+       /*
+        * Make room for the new character (shift the tail of the buffer right).
+        */
+       for (s = &cmdbuf[strlen(cmdbuf)];  s >= cp;  s--)
+               s[clen] = s[0];
+       /*
+        * Insert the character into the buffer.
+        */
+       for (s = cp;  s < cp + clen;  s++)
+               *s = *cs++;
+       /*
+        * Reprint the tail of the line from the inserted char.
+        */
+       cmd_repaint(cp);
+       cmd_right();
+       return (CC_OK);
+}
+
+/*
+ * Backspace in the command buffer.
+ * Delete the char to the left of the cursor.
+ */
+       static int
+cmd_erase()
+{
+       register char *s;
+       int clen;
+
+       if (cp == cmdbuf)
+       {
+               /*
+                * Backspace past beginning of the buffer:
+                * this usually means abort the command.
+                */
+               return (CC_QUIT);
+       }
+       /*
+        * Move cursor left (to the char being erased).
+        */
+       s = cp;
+       cmd_left();
+       clen = s - cp;
+
+       /*
+        * Remove the char from the buffer (shift the buffer left).
+        */
+       for (s = cp;  ;  s++)
+       {
+               s[0] = s[clen];
+               if (s[0] == '\0')
+                       break;
+       }
+
+       /*
+        * Repaint the buffer after the erased char.
+        */
+       cmd_repaint(cp);
+       
+       /*
+        * We say that erasing the entire command string causes us
+        * to abort the current command, if CF_QUIT_ON_ERASE is set.
+        */
+       if ((curr_cmdflags & CF_QUIT_ON_ERASE) && cp == cmdbuf && *cp == '\0')
+               return (CC_QUIT);
+       return (CC_OK);
+}
+
+/*
+ * Delete the char under the cursor.
+ */
+       static int
+cmd_delete()
+{
+       if (*cp == '\0')
+       {
+               /* At end of string; there is no char under the cursor. */
+               return (CC_OK);
+       }
+       /*
+        * Move right, then use cmd_erase.
+        */
+       cmd_right();
+       cmd_erase();
+       return (CC_OK);
+}
+
+/*
+ * Delete the "word" to the left of the cursor.
+ */
+       static int
+cmd_werase()
+{
+       if (cp > cmdbuf && cp[-1] == ' ')
+       {
+               /*
+                * If the char left of cursor is a space,
+                * erase all the spaces left of cursor (to the first non-space).
+                */
+               while (cp > cmdbuf && cp[-1] == ' ')
+                       (void) cmd_erase();
+       } else
+       {
+               /*
+                * If the char left of cursor is not a space,
+                * erase all the nonspaces left of cursor (the whole "word").
+                */
+               while (cp > cmdbuf && cp[-1] != ' ')
+                       (void) cmd_erase();
+       }
+       return (CC_OK);
+}
+
+/*
+ * Delete the "word" under the cursor.
+ */
+       static int
+cmd_wdelete()
+{
+       if (*cp == ' ')
+       {
+               /*
+                * If the char under the cursor is a space,
+                * delete it and all the spaces right of cursor.
+                */
+               while (*cp == ' ')
+                       (void) cmd_delete();
+       } else
+       {
+               /*
+                * If the char under the cursor is not a space,
+                * delete it and all nonspaces right of cursor (the whole word).
+                */
+               while (*cp != ' ' && *cp != '\0')
+                       (void) cmd_delete();
+       }
+       return (CC_OK);
+}
+
+/*
+ * Delete all chars in the command buffer.
+ */
+       static int
+cmd_kill()
+{
+       if (cmdbuf[0] == '\0')
+       {
+               /* Buffer is already empty; abort the current command. */
+               return (CC_QUIT);
+       }
+       cmd_offset = 0;
+       cmd_home();
+       *cp = '\0';
+       cmd_repaint(cp);
+
+       /*
+        * We say that erasing the entire command string causes us
+        * to abort the current command, if CF_QUIT_ON_ERASE is set.
+        */
+       if (curr_cmdflags & CF_QUIT_ON_ERASE)
+               return (CC_QUIT);
+       return (CC_OK);
+}
+
+/*
+ * Select an mlist structure to be the current command history.
+ */
+       public void
+set_mlist(mlist, cmdflags)
+       void *mlist;
+       int cmdflags;
+{
+#if CMD_HISTORY
+       curr_mlist = (struct mlist *) mlist;
+       curr_cmdflags = cmdflags;
+
+       /* Make sure the next up-arrow moves to the last string in the mlist. */
+       if (curr_mlist != NULL)
+               curr_mlist->curr_mp = curr_mlist;
+#endif
+}
+
+#if CMD_HISTORY
+/*
+ * Move up or down in the currently selected command history list.
+ */
+       static int
+cmd_updown(action)
+       int action;
+{
+       char *s;
+       
+       if (curr_mlist == NULL)
+       {
+               /*
+                * The current command has no history list.
+                */
+               bell();
+               return (CC_OK);
+       }
+       cmd_home();
+       clear_eol();
+       /*
+        * Move curr_mp to the next/prev entry.
+        */
+       if (action == EC_UP)
+               curr_mlist->curr_mp = curr_mlist->curr_mp->prev;
+       else
+               curr_mlist->curr_mp = curr_mlist->curr_mp->next;
+       /*
+        * Copy the entry into cmdbuf and echo it on the screen.
+        */
+       s = curr_mlist->curr_mp->string;
+       if (s == NULL)
+               s = "";
+       strcpy(cmdbuf, s);
+       for (cp = cmdbuf;  *cp != '\0';  )
+               cmd_right();
+       return (CC_OK);
+}
+#endif
+
+/*
+ * Add a string to a history list.
+ */
+       public void
+cmd_addhist(mlist, cmd)
+       struct mlist *mlist;
+       char *cmd;
+{
+#if CMD_HISTORY
+       struct mlist *ml;
+       
+       /*
+        * Don't save a trivial command.
+        */
+       if (strlen(cmd) == 0)
+               return;
+
+       /*
+        * Save the command unless it's a duplicate of the
+        * last command in the history.
+        */
+       ml = mlist->prev;
+       if (ml == mlist || strcmp(ml->string, cmd) != 0)
+       {
+               /*
+                * Did not find command in history.
+                * Save the command and put it at the end of the history list.
+                */
+               ml = (struct mlist *) ecalloc(1, sizeof(struct mlist));
+               ml->string = save(cmd);
+               ml->next = mlist;
+               ml->prev = mlist->prev;
+               mlist->prev->next = ml;
+               mlist->prev = ml;
+       }
+       /*
+        * Point to the cmd just after the just-accepted command.
+        * Thus, an UPARROW will always retrieve the previous command.
+        */
+       mlist->curr_mp = ml->next;
+#endif
+}
+
+/*
+ * Accept the command in the command buffer.
+ * Add it to the currently selected history list.
+ */
+       public void
+cmd_accept()
+{
+#if CMD_HISTORY
+       /*
+        * Nothing to do if there is no currently selected history list.
+        */
+       if (curr_mlist == NULL)
+               return;
+       cmd_addhist(curr_mlist, cmdbuf);
+       curr_mlist->modified = 1;
+#endif
+}
+
+/*
+ * Try to perform a line-edit function on the command buffer,
+ * using a specified char as a line-editing command.
+ * Returns:
+ *     CC_PASS The char does not invoke a line edit function.
+ *     CC_OK   Line edit function done.
+ *     CC_QUIT The char requests the current command to be aborted.
+ */
+       static int
+cmd_edit(c)
+       int c;
+{
+       int action;
+       int flags;
+
+#if TAB_COMPLETE_FILENAME
+#define        not_in_completion()     in_completion = 0
+#else
+#define        not_in_completion()
+#endif
+       
+       /*
+        * See if the char is indeed a line-editing command.
+        */
+       flags = 0;
+#if CMD_HISTORY
+       if (curr_mlist == NULL)
+               /*
+                * No current history; don't accept history manipulation cmds.
+                */
+               flags |= EC_NOHISTORY;
+#endif
+#if TAB_COMPLETE_FILENAME
+       if (curr_mlist == ml_search)
+               /*
+                * In a search command; don't accept file-completion cmds.
+                */
+               flags |= EC_NOCOMPLETE;
+#endif
+
+       action = editchar(c, flags);
+
+       switch (action)
+       {
+       case EC_RIGHT:
+               not_in_completion();
+               return (cmd_right());
+       case EC_LEFT:
+               not_in_completion();
+               return (cmd_left());
+       case EC_W_RIGHT:
+               not_in_completion();
+               while (*cp != '\0' && *cp != ' ')
+                       cmd_right();
+               while (*cp == ' ')
+                       cmd_right();
+               return (CC_OK);
+       case EC_W_LEFT:
+               not_in_completion();
+               while (cp > cmdbuf && cp[-1] == ' ')
+                       cmd_left();
+               while (cp > cmdbuf && cp[-1] != ' ')
+                       cmd_left();
+               return (CC_OK);
+       case EC_HOME:
+               not_in_completion();
+               cmd_offset = 0;
+               cmd_home();
+               cmd_repaint(cp);
+               return (CC_OK);
+       case EC_END:
+               not_in_completion();
+               while (*cp != '\0')
+                       cmd_right();
+               return (CC_OK);
+       case EC_INSERT:
+               not_in_completion();
+               return (CC_OK);
+       case EC_BACKSPACE:
+               not_in_completion();
+               return (cmd_erase());
+       case EC_LINEKILL:
+               not_in_completion();
+               return (cmd_kill());
+       case EC_ABORT:
+               not_in_completion();
+               (void) cmd_kill();
+               return (CC_QUIT);
+       case EC_W_BACKSPACE:
+               not_in_completion();
+               return (cmd_werase());
+       case EC_DELETE:
+               not_in_completion();
+               return (cmd_delete());
+       case EC_W_DELETE:
+               not_in_completion();
+               return (cmd_wdelete());
+       case EC_LITERAL:
+               literal = 1;
+               return (CC_OK);
+#if CMD_HISTORY
+       case EC_UP:
+       case EC_DOWN:
+               not_in_completion();
+               return (cmd_updown(action));
+#endif
+#if TAB_COMPLETE_FILENAME
+       case EC_F_COMPLETE:
+       case EC_B_COMPLETE:
+       case EC_EXPAND:
+               return (cmd_complete(action));
+#endif
+       case EC_NOACTION:
+               return (CC_OK);
+       default:
+               not_in_completion();
+               return (CC_PASS);
+       }
+}
+
+#if TAB_COMPLETE_FILENAME
+/*
+ * Insert a string into the command buffer, at the current position.
+ */
+       static int
+cmd_istr(str)
+       char *str;
+{
+       char *s;
+       int action;
+       char *endline = str + strlen(str);
+       
+       for (s = str;  *s != '\0';  )
+       {
+               char *os = s;
+               step_char(&s, +1, endline);
+               action = cmd_ichar(os, s - os);
+               if (action != CC_OK)
+               {
+                       bell();
+                       return (action);
+               }
+       }
+       return (CC_OK);
+}
+
+/*
+ * Find the beginning and end of the "current" word.
+ * This is the word which the cursor (cp) is inside or at the end of.
+ * Return pointer to the beginning of the word and put the
+ * cursor at the end of the word.
+ */
+       static char *
+delimit_word()
+{
+       char *word;
+#if SPACES_IN_FILENAMES
+       char *p;
+       int delim_quoted = 0;
+       int meta_quoted = 0;
+       char *esc = get_meta_escape();
+       int esclen = strlen(esc);
+#endif
+       
+       /*
+        * Move cursor to end of word.
+        */
+       if (*cp != ' ' && *cp != '\0')
+       {
+               /*
+                * Cursor is on a nonspace.
+                * Move cursor right to the next space.
+                */
+               while (*cp != ' ' && *cp != '\0')
+                       cmd_right();
+       } else if (cp > cmdbuf && cp[-1] != ' ')
+       {
+               /*
+                * Cursor is on a space, and char to the left is a nonspace.
+                * We're already at the end of the word.
+                */
+               ;
+#if 0
+       } else
+       {
+               /*
+                * Cursor is on a space and char to the left is a space.
+                * Huh? There's no word here.
+                */
+               return (NULL);
+#endif
+       }
+       /*
+        * Find the beginning of the word which the cursor is in.
+        */
+       if (cp == cmdbuf)
+               return (NULL);
+#if SPACES_IN_FILENAMES
+       /*
+        * If we have an unbalanced quote (that is, an open quote
+        * without a corresponding close quote), we return everything
+        * from the open quote, including spaces.
+        */
+       for (word = cmdbuf;  word < cp;  word++)
+               if (*word != ' ')
+                       break;
+       if (word >= cp)
+               return (cp);
+       for (p = cmdbuf;  p < cp;  p++)
+       {
+               if (meta_quoted)
+               {
+                       meta_quoted = 0;
+               } else if (esclen > 0 && p + esclen < cp &&
+                          strncmp(p, esc, esclen) == 0)
+               {
+                       meta_quoted = 1;
+                       p += esclen - 1;
+               } else if (delim_quoted)
+               {
+                       if (*p == closequote)
+                               delim_quoted = 0;
+               } else /* (!delim_quoted) */
+               {
+                       if (*p == openquote)
+                               delim_quoted = 1;
+                       else if (*p == ' ')
+                               word = p+1;
+               }
+       }
+#endif
+       return (word);
+}
+
+/*
+ * Set things up to enter completion mode.
+ * Expand the word under the cursor into a list of filenames 
+ * which start with that word, and set tk_text to that list.
+ */
+       static void
+init_compl()
+{
+       char *word;
+       char c;
+       
+       /*
+        * Get rid of any previous tk_text.
+        */
+       if (tk_text != NULL)
+       {
+               free(tk_text);
+               tk_text = NULL;
+       }
+       /*
+        * Find the original (uncompleted) word in the command buffer.
+        */
+       word = delimit_word();
+       if (word == NULL)
+               return;
+       /*
+        * Set the insertion point to the point in the command buffer
+        * where the original (uncompleted) word now sits.
+        */
+       tk_ipoint = word;
+       /*
+        * Save the original (uncompleted) word
+        */
+       if (tk_original != NULL)
+               free(tk_original);
+       tk_original = (char *) ecalloc(cp-word+1, sizeof(char));
+       strncpy(tk_original, word, cp-word);
+       /*
+        * Get the expanded filename.
+        * This may result in a single filename, or
+        * a blank-separated list of filenames.
+        */
+       c = *cp;
+       *cp = '\0';
+       if (*word != openquote)
+       {
+               tk_text = fcomplete(word);
+       } else
+       {
+               char *qword = shell_quote(word+1);
+               if (qword == NULL)
+                       tk_text = fcomplete(word+1);
+               else
+               {
+                       tk_text = fcomplete(qword);
+                       free(qword);
+               }
+       }
+       *cp = c;
+}
+
+/*
+ * Return the next word in the current completion list.
+ */
+       static char *
+next_compl(action, prev)
+       int action;
+       char *prev;
+{
+       switch (action)
+       {
+       case EC_F_COMPLETE:
+               return (forw_textlist(&tk_tlist, prev));
+       case EC_B_COMPLETE:
+               return (back_textlist(&tk_tlist, prev));
+       }
+       /* Cannot happen */
+       return ("?");
+}
+
+/*
+ * Complete the filename before (or under) the cursor.
+ * cmd_complete may be called multiple times.  The global in_completion
+ * remembers whether this call is the first time (create the list),
+ * or a subsequent time (step thru the list).
+ */
+       static int
+cmd_complete(action)
+       int action;
+{
+       char *s;
+
+       if (!in_completion || action == EC_EXPAND)
+       {
+               /*
+                * Expand the word under the cursor and 
+                * use the first word in the expansion 
+                * (or the entire expansion if we're doing EC_EXPAND).
+                */
+               init_compl();
+               if (tk_text == NULL)
+               {
+                       bell();
+                       return (CC_OK);
+               }
+               if (action == EC_EXPAND)
+               {
+                       /*
+                        * Use the whole list.
+                        */
+                       tk_trial = tk_text;
+               } else
+               {
+                       /*
+                        * Use the first filename in the list.
+                        */
+                       in_completion = 1;
+                       init_textlist(&tk_tlist, tk_text);
+                       tk_trial = next_compl(action, (char*)NULL);
+               }
+       } else
+       {
+               /*
+                * We already have a completion list.
+                * Use the next/previous filename from the list.
+                */
+               tk_trial = next_compl(action, tk_trial);
+       }
+       
+       /*
+        * Remove the original word, or the previous trial completion.
+        */
+       while (cp > tk_ipoint)
+               (void) cmd_erase();
+       
+       if (tk_trial == NULL)
+       {
+               /*
+                * There are no more trial completions.
+                * Insert the original (uncompleted) filename.
+                */
+               in_completion = 0;
+               if (cmd_istr(tk_original) != CC_OK)
+                       goto fail;
+       } else
+       {
+               /*
+                * Insert trial completion.
+                */
+               if (cmd_istr(tk_trial) != CC_OK)
+                       goto fail;
+               /*
+                * If it is a directory, append a slash.
+                */
+               if (is_dir(tk_trial))
+               {
+                       if (cp > cmdbuf && cp[-1] == closequote)
+                               (void) cmd_erase();
+                       s = lgetenv("LESSSEPARATOR");
+                       if (s == NULL)
+                               s = PATHNAME_SEP;
+                       if (cmd_istr(s) != CC_OK)
+                               goto fail;
+               }
+       }
+       
+       return (CC_OK);
+       
+fail:
+       in_completion = 0;
+       bell();
+       return (CC_OK);
+}
+
+#endif /* TAB_COMPLETE_FILENAME */
+
+/*
+ * Process a single character of a multi-character command, such as
+ * a number, or the pattern of a search command.
+ * Returns:
+ *     CC_OK           The char was accepted.
+ *     CC_QUIT         The char requests the command to be aborted.
+ *     CC_ERROR        The char could not be accepted due to an error.
+ */
+       public int
+cmd_char(c)
+       int c;
+{
+       int action;
+       int len;
+
+       if (!utf_mode)
+       {
+               cmd_mbc_buf[0] = c;
+               len = 1;
+       } else
+       {
+               /* Perform strict validation in all possible cases.  */
+               if (cmd_mbc_buf_len == 0)
+               {
+                retry:
+                       cmd_mbc_buf_index = 1;
+                       *cmd_mbc_buf = c;
+                       if (IS_ASCII_OCTET(c))
+                               cmd_mbc_buf_len = 1;
+                       else if (IS_UTF8_LEAD(c))
+                       {
+                               cmd_mbc_buf_len = utf_len(c);
+                               return (CC_OK);
+                       } else
+                       {
+                               /* UTF8_INVALID or stray UTF8_TRAIL */
+                               bell();
+                               return (CC_ERROR);
+                       }
+               } else if (IS_UTF8_TRAIL(c))
+               {
+                       cmd_mbc_buf[cmd_mbc_buf_index++] = c;
+                       if (cmd_mbc_buf_index < cmd_mbc_buf_len)
+                               return (CC_OK);
+                       if (!is_utf8_well_formed(cmd_mbc_buf))
+                       {
+                               /* complete, but not well formed (non-shortest form), sequence */
+                               cmd_mbc_buf_len = 0;
+                               bell();
+                               return (CC_ERROR);
+                       }
+               } else
+               {
+                       /* Flush incomplete (truncated) sequence.  */
+                       cmd_mbc_buf_len = 0;
+                       bell();
+                       /* Handle new char.  */
+                       goto retry;
+               }
+
+               len = cmd_mbc_buf_len;
+               cmd_mbc_buf_len = 0;
+       }
+
+       if (literal)
+       {
+               /*
+                * Insert the char, even if it is a line-editing char.
+                */
+               literal = 0;
+               return (cmd_ichar(cmd_mbc_buf, len));
+       }
+               
+       /*
+        * See if it is a line-editing character.
+        */
+       if (in_mca() && len == 1)
+       {
+               action = cmd_edit(c);
+               switch (action)
+               {
+               case CC_OK:
+               case CC_QUIT:
+                       return (action);
+               case CC_PASS:
+                       break;
+               }
+       }
+       
+       /*
+        * Insert the char into the command buffer.
+        */
+       return (cmd_ichar(cmd_mbc_buf, len));
+}
+
+/*
+ * Return the number currently in the command buffer.
+ */
+       public LINENUM
+cmd_int(frac)
+       long *frac;
+{
+       char *p;
+       LINENUM n = 0;
+       int err;
+
+       for (p = cmdbuf;  *p >= '0' && *p <= '9';  p++)
+               n = (n * 10) + (*p - '0');
+       *frac = 0;
+       if (*p++ == '.')
+       {
+               *frac = getfraction(&p, NULL, &err);
+               /* {{ do something if err is set? }} */
+       }
+       return (n);
+}
+
+/*
+ * Return a pointer to the command buffer.
+ */
+       public char *
+get_cmdbuf()
+{
+       return (cmdbuf);
+}
+
+#if CMD_HISTORY
+/*
+ * Return the last (most recent) string in the current command history.
+ */
+       public char *
+cmd_lastpattern()
+{
+       if (curr_mlist == NULL)
+               return (NULL);
+       return (curr_mlist->curr_mp->prev->string);
+}
+#endif
+
+#if CMD_HISTORY
+/*
+ * Get the name of the history file.
+ */
+       static char *
+histfile_name()
+{
+       char *home;
+       char *name;
+       int len;
+       
+       /* See if filename is explicitly specified by $LESSHISTFILE. */
+       name = lgetenv("LESSHISTFILE");
+       if (name != NULL && *name != '\0')
+       {
+               if (strcmp(name, "-") == 0 || strcmp(name, "/dev/null") == 0)
+                       /* $LESSHISTFILE == "-" means don't use a history file. */
+                       return (NULL);
+               return (save(name));
+       }
+
+       /* Otherwise, file is in $HOME. */
+       home = lgetenv("HOME");
+       if (home == NULL || *home == '\0')
+       {
+#if OS2
+               home = lgetenv("INIT");
+               if (home == NULL || *home == '\0')
+#endif
+                       return (NULL);
+       }
+       len = strlen(home) + strlen(LESSHISTFILE) + 2;
+       name = (char *) ecalloc(len, sizeof(char));
+       SNPRINTF2(name, len, "%s/%s", home, LESSHISTFILE);
+       return (name);
+}
+#endif /* CMD_HISTORY */
+
+/*
+ * Initialize history from a .lesshist file.
+ */
+       public void
+init_cmdhist()
+{
+#if CMD_HISTORY
+       struct mlist *ml = NULL;
+       char line[CMDBUF_SIZE];
+       char *filename;
+       FILE *f;
+       char *p;
+
+       filename = histfile_name();
+       if (filename == NULL)
+               return;
+       f = fopen(filename, "r");
+       free(filename);
+       if (f == NULL)
+               return;
+       if (fgets(line, sizeof(line), f) == NULL ||
+           strncmp(line, HISTFILE_FIRST_LINE, strlen(HISTFILE_FIRST_LINE)) != 0)
+       {
+               fclose(f);
+               return;
+       }
+       while (fgets(line, sizeof(line), f) != NULL)
+       {
+               for (p = line;  *p != '\0';  p++)
+               {
+                       if (*p == '\n' || *p == '\r')
+                       {
+                               *p = '\0';
+                               break;
+                       }
+               }
+               if (strcmp(line, HISTFILE_SEARCH_SECTION) == 0)
+                       ml = &mlist_search;
+               else if (strcmp(line, HISTFILE_SHELL_SECTION) == 0)
+               {
+#if SHELL_ESCAPE || PIPEC
+                       ml = &mlist_shell;
+#else
+                       ml = NULL;
+#endif
+               } else if (*line == '"')
+               {
+                       if (ml != NULL)
+                               cmd_addhist(ml, line+1);
+               }
+       }
+       fclose(f);
+#endif /* CMD_HISTORY */
+}
+
+/*
+ *
+ */
+#if CMD_HISTORY
+       static void
+save_mlist(ml, f)
+       struct mlist *ml;
+       FILE *f;
+{
+       int histsize = 0;
+       int n;
+       char *s;
+
+       s = lgetenv("LESSHISTSIZE");
+       if (s != NULL)
+               histsize = atoi(s);
+       if (histsize == 0)
+               histsize = 100;
+
+       ml = ml->prev;
+       for (n = 0;  n < histsize;  n++)
+       {
+               if (ml->string == NULL)
+                       break;
+               ml = ml->prev;
+       }
+       for (ml = ml->next;  ml->string != NULL;  ml = ml->next)
+               fprintf(f, "\"%s\n", ml->string);
+}
+#endif /* CMD_HISTORY */
+
+/*
+ *
+ */
+       public void
+save_cmdhist()
+{
+#if CMD_HISTORY
+       char *filename;
+       FILE *f;
+       int modified = 0;
+
+       filename = histfile_name();
+       if (filename == NULL)
+               return;
+       if (mlist_search.modified)
+               modified = 1;
+#if SHELL_ESCAPE || PIPEC
+       if (mlist_shell.modified)
+               modified = 1;
+#endif
+       if (!modified)
+               return;
+       f = fopen(filename, "w");
+       free(filename);
+       if (f == NULL)
+               return;
+#if HAVE_FCHMOD
+{
+       /* Make history file readable only by owner. */
+       int do_chmod = 1;
+#if HAVE_STAT
+       struct stat statbuf;
+       int r = fstat(fileno(f), &statbuf);
+       if (r < 0 || !S_ISREG(statbuf.st_mode))
+               /* Don't chmod if not a regular file. */
+               do_chmod = 0;
+#endif
+       if (do_chmod)
+               fchmod(fileno(f), 0600);
+}
+#endif
+
+       fprintf(f, "%s\n", HISTFILE_FIRST_LINE);
+
+       fprintf(f, "%s\n", HISTFILE_SEARCH_SECTION);
+       save_mlist(&mlist_search, f);
+
+#if SHELL_ESCAPE || PIPEC
+       fprintf(f, "%s\n", HISTFILE_SHELL_SECTION);
+       save_mlist(&mlist_shell, f);
+#endif
+
+       fclose(f);
+#endif /* CMD_HISTORY */
+}