/*
* Copyright (C) 1984-2023 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, see the README file.
*/
/*
* An IFILE represents an input file.
*
* It is actually a pointer to an ifile structure,
* but is opaque outside this module.
* Ifile structures are kept in a linked list in the order they
* appear on the command line.
* Any new file which does not already appear in the list is
* inserted after the current file.
*/
#include "less.h"
extern IFILE curr_ifile;
struct ifile {
struct ifile *h_next; /* Links for command line list */
struct ifile *h_prev;
char *h_filename; /* Name of the file */
char *h_rfilename; /* Canonical name of the file */
void *h_filestate; /* File state (used in ch.c) */
int h_index; /* Index within command line list */
int h_hold; /* Hold count */
char h_opened; /* Has this ifile been opened? */
struct scrpos h_scrpos; /* Saved position within the file */
void *h_altpipe; /* Alt pipe */
char *h_altfilename; /* Alt filename */
};
/*
* Convert an IFILE (external representation)
* to a struct file (internal representation), and vice versa.
*/
#define int_ifile(h) ((struct ifile *)(h))
#define ext_ifile(h) ((IFILE)(h))
static void incr_index(struct ifile *p, int incr)
{
for (; p != &anchor; p = p->h_next)
p->h_index += incr;
}
/*
* Link an ifile into the ifile list.
*/
static void link_ifile(struct ifile *p, struct ifile *prev)
{
/*
* Link into list.
*/
if (prev == NULL)
prev = &anchor;
p->h_next = prev->h_next;
p->h_prev = prev;
prev->h_next->h_prev = p;
prev->h_next = p;
/*
* Calculate index for the new one,
* and adjust the indexes for subsequent ifiles in the list.
*/
p->h_index = prev->h_index + 1;
incr_index(p->h_next, 1);
ifiles++;
}
/*
* Unlink an ifile from the ifile list.
*/
static void unlink_ifile(struct ifile *p)
{
p->h_next->h_prev = p->h_prev;
p->h_prev->h_next = p->h_next;
incr_index(p->h_next, -1);
ifiles--;
}
/*
* Allocate a new ifile structure and stick a filename in it.
* It should go after "prev" in the list
* (or at the beginning of the list if "prev" is NULL).
* Return a pointer to the new ifile structure.
*/
static struct ifile * new_ifile(char *filename, struct ifile *prev)
{
struct ifile *p;
/*
* Allocate and initialize structure.
*/
p = (struct ifile *) ecalloc(1, sizeof(struct ifile));
p->h_filename = save(filename);
p->h_rfilename = lrealpath(filename);
p->h_scrpos.pos = NULL_POSITION;
p->h_opened = 0;
p->h_hold = 0;
p->h_filestate = NULL;
p->h_altfilename = NULL;
p->h_altpipe = NULL;
link_ifile(p, prev);
/*
* {{ It's dodgy to call mark.c functions from here;
* there is potentially dangerous recursion.
* Probably need to revisit this design. }}
*/
mark_check_ifile(ext_ifile(p));
return (p);
}
/*
* Delete an existing ifile structure.
*/
public void del_ifile(IFILE h)
{
struct ifile *p;
if (h == NULL_IFILE)
return;
/*
* If the ifile we're deleting is the currently open ifile,
* move off it.
*/
unmark(h);
if (h == curr_ifile)
curr_ifile = getoff_ifile(curr_ifile);
p = int_ifile(h);
unlink_ifile(p);
free(p->h_rfilename);
free(p->h_filename);
free(p);
}
/*
* Get the ifile after a given one in the list.
*/
public IFILE next_ifile(IFILE h)
{
struct ifile *p;
p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
if (p->h_next == &anchor)
return (NULL_IFILE);
return (ext_ifile(p->h_next));
}
/*
* Get the ifile before a given one in the list.
*/
public IFILE prev_ifile(IFILE h)
{
struct ifile *p;
p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
if (p->h_prev == &anchor)
return (NULL_IFILE);
return (ext_ifile(p->h_prev));
}
/*
* Return a different ifile from the given one.
*/
public IFILE getoff_ifile(IFILE ifile)
{
IFILE newifile;
if ((newifile = prev_ifile(ifile)) != NULL_IFILE)
return (newifile);
if ((newifile = next_ifile(ifile)) != NULL_IFILE)
return (newifile);
return (NULL_IFILE);
}
/*
* Return the number of ifiles.
*/
public int nifile(void)
{
return (ifiles);
}
/*
* Find an ifile structure, given a filename.
*/
static struct ifile * find_ifile(char *filename)
{
struct ifile *p;
char *rfilename = lrealpath(filename);
for (p = anchor.h_next; p != &anchor; p = p->h_next)
{
if (strcmp(rfilename, p->h_rfilename) == 0)
{
/*
* If given name is shorter than the name we were
* previously using for this file, adopt shorter name.
*/
if (strlen(filename) < strlen(p->h_filename))
{
free(p->h_filename);
p->h_filename = save(filename);
}
break;
}
}
free(rfilename);
if (p == &anchor)
p = NULL;
return (p);
}
/*
* Get the ifile associated with a filename.
* If the filename has not been seen before,
* insert the new ifile after "prev" in the list.
*/
public IFILE get_ifile(char *filename, IFILE prev)
{
struct ifile *p;
if ((p = find_ifile(filename)) == NULL)
p = new_ifile(filename, int_ifile(prev));
return (ext_ifile(p));
}
/*
* Get the display filename associated with a ifile.
*/
public char * get_filename(IFILE ifile)
{
if (ifile == NULL)
return (NULL);
return (int_ifile(ifile)->h_filename);
}
/*
* Get the canonical filename associated with a ifile.
*/
public char * get_real_filename(IFILE ifile)
{
if (ifile == NULL)
return (NULL);
return (int_ifile(ifile)->h_rfilename);
}
/*
* Get the index of the file associated with a ifile.
*/
public int get_index(IFILE ifile)
{
return (int_ifile(ifile)->h_index);
}
/*
* Save the file position to be associated with a given file.
*/
public void store_pos(IFILE ifile, struct scrpos *scrpos)
{
int_ifile(ifile)->h_scrpos = *scrpos;
}
/*
* Recall the file position associated with a file.
* If no position has been associated with the file, return NULL_POSITION.
*/
public void get_pos(IFILE ifile, struct scrpos *scrpos)
{
*scrpos = int_ifile(ifile)->h_scrpos;
}
/*
* Mark the ifile as "opened".
*/
public void set_open(IFILE ifile)
{
int_ifile(ifile)->h_opened = 1;
}
/*
* Return whether the ifile has been opened previously.
*/
public int opened(IFILE ifile)
{
return (int_ifile(ifile)->h_opened);
}
public void hold_ifile(IFILE ifile, int incr)
{
int_ifile(ifile)->h_hold += incr;
}
public int held_ifile(IFILE ifile)
{
return (int_ifile(ifile)->h_hold);
}
public void * get_filestate(IFILE ifile)
{
return (int_ifile(ifile)->h_filestate);
}
