2 * Copyright (C) 1984-2000 Mark Nudelman
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
7 * For more information about less, or for information on how to
8 * contact the author, see the README file.
13 * An IFILE represents an input file.
15 * It is actually a pointer to an ifile structure,
16 * but is opaque outside this module.
17 * Ifile structures are kept in a linked list in the order they
18 * appear on the command line.
19 * Any new file which does not already appear in the list is
20 * inserted after the current file.
25 extern IFILE curr_ifile;
28 struct ifile *h_next; /* Links for command line list */
30 char *h_filename; /* Name of the file */
31 void *h_filestate; /* File state (used in ch.c) */
32 int h_index; /* Index within command line list */
33 int h_hold; /* Hold count */
34 char h_opened; /* Has this ifile been opened? */
35 struct scrpos h_scrpos; /* Saved position within the file */
39 * Convert an IFILE (external representation)
40 * to a struct file (internal representation), and vice versa.
42 #define int_ifile(h) ((struct ifile *)(h))
43 #define ext_ifile(h) ((IFILE)(h))
46 * Anchor for linked list.
48 static struct ifile anchor = { &anchor, &anchor, NULL, NULL, 0, 0, '\0',
49 { NULL_POSITION, 0 } };
50 static int ifiles = 0;
54 register struct ifile *p;
57 for (; p != &anchor; p = p->h_next)
62 * Link an ifile into the ifile list.
74 p->h_next = prev->h_next;
76 prev->h_next->h_prev = p;
79 * Calculate index for the new one,
80 * and adjust the indexes for subsequent ifiles in the list.
82 p->h_index = prev->h_index + 1;
83 incr_index(p->h_next, 1);
88 * Unlink an ifile from the ifile list.
94 p->h_next->h_prev = p->h_prev;
95 p->h_prev->h_next = p->h_next;
96 incr_index(p->h_next, -1);
101 * Allocate a new ifile structure and stick a filename in it.
102 * It should go after "prev" in the list
103 * (or at the beginning of the list if "prev" is NULL).
104 * Return a pointer to the new ifile structure.
106 static struct ifile *
107 new_ifile(filename, prev)
111 register struct ifile *p;
114 * Allocate and initialize structure.
116 p = (struct ifile *) ecalloc(1, sizeof(struct ifile));
117 p->h_filename = save(filename);
118 p->h_scrpos.pos = NULL_POSITION;
121 p->h_filestate = NULL;
127 * Delete an existing ifile structure.
133 register struct ifile *p;
138 * If the ifile we're deleting is the currently open ifile,
143 curr_ifile = getoff_ifile(curr_ifile);
151 * Get the ifile after a given one in the list.
157 register struct ifile *p;
159 p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
160 if (p->h_next == &anchor)
162 return (ext_ifile(p->h_next));
166 * Get the ifile before a given one in the list.
172 register struct ifile *p;
174 p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
175 if (p->h_prev == &anchor)
177 return (ext_ifile(p->h_prev));
181 * Return a different ifile from the given one.
189 if ((newifile = prev_ifile(ifile)) != NULL_IFILE)
191 if ((newifile = next_ifile(ifile)) != NULL_IFILE)
197 * Return the number of ifiles.
206 * Find an ifile structure, given a filename.
208 static struct ifile *
212 register struct ifile *p;
214 for (p = anchor.h_next; p != &anchor; p = p->h_next)
215 if (strcmp(filename, p->h_filename) == 0)
221 * Get the ifile associated with a filename.
222 * If the filename has not been seen before,
223 * insert the new ifile after "prev" in the list.
226 get_ifile(filename, prev)
230 register struct ifile *p;
232 if ((p = find_ifile(filename)) == NULL)
233 p = new_ifile(filename, int_ifile(prev));
234 return (ext_ifile(p));
238 * Get the filename associated with a ifile.
246 return (int_ifile(ifile)->h_filename);
250 * Get the index of the file associated with a ifile.
256 return (int_ifile(ifile)->h_index);
260 * Save the file position to be associated with a given file.
263 store_pos(ifile, scrpos)
265 struct scrpos *scrpos;
267 int_ifile(ifile)->h_scrpos = *scrpos;
271 * Recall the file position associated with a file.
272 * If no position has been associated with the file, return NULL_POSITION.
275 get_pos(ifile, scrpos)
277 struct scrpos *scrpos;
279 *scrpos = int_ifile(ifile)->h_scrpos;
283 * Mark the ifile as "opened".
289 int_ifile(ifile)->h_opened = 1;
293 * Return whether the ifile has been opened previously.
299 return (int_ifile(ifile)->h_opened);
303 hold_ifile(ifile, incr)
307 int_ifile(ifile)->h_hold += incr;
314 return (int_ifile(ifile)->h_hold);
321 return (int_ifile(ifile)->h_filestate);
325 set_filestate(ifile, filestate)
329 int_ifile(ifile)->h_filestate = filestate;
336 register struct ifile *p;
338 for (p = anchor.h_next; p != &anchor; p = p->h_next)
340 printf("%x: %d. <%s> pos %d,%x\n",
341 p, p->h_index, p->h_filename,
342 p->h_scrpos.ln, p->h_scrpos.pos);
343 ch_dump(p->h_filestate);