freebsd-dev/contrib/libreadline/histsearch.c
Andrey A. Chernov c7765a607b Libreadline.
1997-01-04 22:09:20 +00:00

198 lines
4.9 KiB
C

/* histsearch.c -- searching the history list. */
/* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
This file contains the GNU History Library (the Library), a set of
routines for managing the text of previously typed lines.
The Library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
The Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
The GNU General Public License is often shipped with GNU software, and
is generally kept in a file called COPYING or LICENSE. If you do not
have a copy of the license, write to the Free Software Foundation,
675 Mass Ave, Cambridge, MA 02139, USA. */
#define READLINE_LIBRARY
#if defined (HAVE_CONFIG_H)
# include <config.h>
#endif
#include <stdio.h>
#if defined (HAVE_STDLIB_H)
# include <stdlib.h>
#else
# include "ansi_stdlib.h"
#endif /* HAVE_STDLIB_H */
#if defined (HAVE_UNISTD_H)
# include <unistd.h>
#endif
#if defined (HAVE_STRING_H)
# include <string.h>
#else
# include <strings.h>
#endif /* !HAVE_STRING_H */
#include "history.h"
#include "histlib.h"
/* Variables imported from other history library files. */
extern int history_offset;
/* The list of alternate characters that can delimit a history search
string. */
char *history_search_delimiter_chars = (char *)NULL;
/* Search the history for STRING, starting at history_offset.
If DIRECTION < 0, then the search is through previous entries, else
through subsequent. If ANCHORED is non-zero, the string must
appear at the beginning of a history line, otherwise, the string
may appear anywhere in the line. If the string is found, then
current_history () is the history entry, and the value of this
function is the offset in the line of that history entry that the
string was found in. Otherwise, nothing is changed, and a -1 is
returned. */
static int
history_search_internal (string, direction, anchored)
char *string;
int direction, anchored;
{
register int i, reverse;
register char *line;
register int line_index;
int string_len;
HIST_ENTRY **the_history; /* local */
i = history_offset;
reverse = (direction < 0);
/* Take care of trivial cases first. */
if (string == 0 || *string == '\0')
return (-1);
if (!history_length || ((i == history_length) && !reverse))
return (-1);
if (reverse && (i == history_length))
i--;
#define NEXT_LINE() do { if (reverse) i--; else i++; } while (0)
the_history = history_list ();
string_len = strlen (string);
while (1)
{
/* Search each line in the history list for STRING. */
/* At limit for direction? */
if ((reverse && i < 0) || (!reverse && i == history_length))
return (-1);
line = the_history[i]->line;
line_index = strlen (line);
/* If STRING is longer than line, no match. */
if (string_len > line_index)
{
NEXT_LINE ();
continue;
}
/* Handle anchored searches first. */
if (anchored == ANCHORED_SEARCH)
{
if (STREQN (string, line, string_len))
{
history_offset = i;
return (0);
}
NEXT_LINE ();
continue;
}
/* Do substring search. */
if (reverse)
{
line_index -= string_len;
while (line_index >= 0)
{
if (STREQN (string, line + line_index, string_len))
{
history_offset = i;
return (line_index);
}
line_index--;
}
}
else
{
register int limit;
limit = line_index - string_len + 1;
line_index = 0;
while (line_index < limit)
{
if (STREQN (string, line + line_index, string_len))
{
history_offset = i;
return (line_index);
}
line_index++;
}
}
NEXT_LINE ();
}
}
/* Do a non-anchored search for STRING through the history in DIRECTION. */
int
history_search (string, direction)
char *string;
int direction;
{
return (history_search_internal (string, direction, NON_ANCHORED_SEARCH));
}
/* Do an anchored search for string through the history in DIRECTION. */
int
history_search_prefix (string, direction)
char *string;
int direction;
{
return (history_search_internal (string, direction, ANCHORED_SEARCH));
}
/* Search for STRING in the history list. DIR is < 0 for searching
backwards. POS is an absolute index into the history list at
which point to begin searching. */
int
history_search_pos (string, dir, pos)
char *string;
int dir, pos;
{
int ret, old;
old = where_history ();
history_set_pos (pos);
if (history_search (string, dir) == -1)
{
history_set_pos (old);
return (-1);
}
ret = where_history ();
history_set_pos (old);
return ret;
}