freebsd-dev/contrib/less/mark.c

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/*
* Copyright (C) 1984-2000 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.
*/
#include "less.h"
extern IFILE curr_ifile;
extern int sc_height;
extern int jump_sline;
/*
* A mark is an ifile (input file) plus a position within the file.
*/
struct mark {
IFILE m_ifile;
struct scrpos m_scrpos;
};
/*
* The table of marks.
* Each mark is identified by a lowercase or uppercase letter.
* The final one is lmark, for the "last mark"; addressed by the apostrophe.
*/
#define NMARKS ((2*26)+1) /* a-z, A-Z, lastmark */
#define LASTMARK (NMARKS-1)
static struct mark marks[NMARKS];
/*
* Initialize the mark table to show no marks are set.
*/
public void
init_mark()
{
int i;
for (i = 0; i < NMARKS; i++)
marks[i].m_scrpos.pos = NULL_POSITION;
}
/*
* See if a mark letter is valid (between a and z).
*/
static struct mark *
getumark(c)
int c;
{
if (c >= 'a' && c <= 'z')
return (&marks[c-'a']);
if (c >= 'A' && c <= 'Z')
return (&marks[c-'A'+26]);
error("Invalid mark letter", NULL_PARG);
return (NULL);
}
/*
* Get the mark structure identified by a character.
* The mark struct may come either from the mark table
* or may be constructed on the fly for certain characters like ^, $.
*/
static struct mark *
getmark(c)
int c;
{
register struct mark *m;
static struct mark sm;
switch (c)
{
case '^':
/*
* Beginning of the current file.
*/
m = &sm;
m->m_scrpos.pos = ch_zero();
m->m_scrpos.ln = 0;
m->m_ifile = curr_ifile;
break;
case '$':
/*
* End of the current file.
*/
if (ch_end_seek())
{
error("Cannot seek to end of file", NULL_PARG);
return (NULL);
}
m = &sm;
m->m_scrpos.pos = ch_tell();
m->m_scrpos.ln = sc_height-1;
m->m_ifile = curr_ifile;
break;
case '.':
/*
* Current position in the current file.
*/
m = &sm;
get_scrpos(&m->m_scrpos);
m->m_ifile = curr_ifile;
break;
case '\'':
/*
* The "last mark".
*/
m = &marks[LASTMARK];
break;
default:
/*
* Must be a user-defined mark.
*/
m = getumark(c);
if (m == NULL)
break;
if (m->m_scrpos.pos == NULL_POSITION)
{
error("Mark not set", NULL_PARG);
return (NULL);
}
break;
}
return (m);
}
/*
* Is a mark letter is invalid?
*/
public int
badmark(c)
int c;
{
return (getmark(c) == NULL);
}
/*
* Set a user-defined mark.
*/
public void
setmark(c)
int c;
{
register struct mark *m;
struct scrpos scrpos;
m = getumark(c);
if (m == NULL)
return;
get_scrpos(&scrpos);
m->m_scrpos = scrpos;
m->m_ifile = curr_ifile;
}
/*
* Set lmark (the mark named by the apostrophe).
*/
public void
lastmark()
{
struct scrpos scrpos;
if (ch_getflags() & CH_HELPFILE)
return;
get_scrpos(&scrpos);
if (scrpos.pos == NULL_POSITION)
return;
marks[LASTMARK].m_scrpos = scrpos;
marks[LASTMARK].m_ifile = curr_ifile;
}
/*
* Go to a mark.
*/
public void
gomark(c)
int c;
{
register struct mark *m;
struct scrpos scrpos;
m = getmark(c);
if (m == NULL)
return;
/*
* If we're trying to go to the lastmark and
* it has not been set to anything yet,
* set it to the beginning of the current file.
*/
if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
{
m->m_ifile = curr_ifile;
m->m_scrpos.pos = ch_zero();
m->m_scrpos.ln = jump_sline;
}
/*
* If we're using lmark, we must save the screen position now,
* because if we call edit_ifile() below, lmark will change.
* (We save the screen position even if we're not using lmark.)
*/
scrpos = m->m_scrpos;
if (m->m_ifile != curr_ifile)
{
/*
* Not in the current file; edit the correct file.
*/
if (edit_ifile(m->m_ifile))
return;
}
jump_loc(scrpos.pos, scrpos.ln);
}
/*
* Return the position associated with a given mark letter.
*
* We don't return which screen line the position
* is associated with, but this doesn't matter much,
* because it's always the first non-blank line on the screen.
*/
public POSITION
markpos(c)
int c;
{
register struct mark *m;
m = getmark(c);
if (m == NULL)
return (NULL_POSITION);
if (m->m_ifile != curr_ifile)
{
error("Mark not in current file", NULL_PARG);
return (NULL_POSITION);
}
return (m->m_scrpos.pos);
}
/*
* Clear the marks associated with a specified ifile.
*/
public void
unmark(ifile)
IFILE ifile;
{
int i;
for (i = 0; i < NMARKS; i++)
if (marks[i].m_ifile == ifile)
marks[i].m_scrpos.pos = NULL_POSITION;
}