1 /*
2 * Copyright (C) 1984-2024 Mark Nudelman
3 *
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.
6 *
7 * For more information, see the README file.
8 */
9
10
11 /*
12 * An IFILE represents an input file.
13 *
14 * It is actually a pointer to an ifile structure,
15 * but is opaque outside this module.
16 * Ifile structures are kept in a linked list in the order they
17 * appear on the command line.
18 * Any new file which does not already appear in the list is
19 * inserted after the current file.
20 */
21
22 #include "less.h"
23
24 extern IFILE curr_ifile;
25
26 struct ifile {
27 struct ifile *h_next; /* Links for command line list */
28 struct ifile *h_prev;
29 char *h_filename; /* Name of the file */
30 char *h_rfilename; /* Canonical 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 */
36 void *h_altpipe; /* Alt pipe */
37 char *h_altfilename; /* Alt filename */
38 };
39
40 /*
41 * Convert an IFILE (external representation)
42 * to a struct file (internal representation), and vice versa.
43 */
44 #define int_ifile(h) ((struct ifile *)(h))
45 #define ext_ifile(h) ((IFILE)(h))
46
47 /*
48 * Anchor for linked list.
49 */
50 static struct ifile anchor = { &anchor, &anchor, NULL, NULL, NULL, 0, 0, '\0',
51 { NULL_POSITION, 0 }, NULL, NULL };
52 static int ifiles = 0;
53
incr_index(struct ifile * p,int incr)54 static void incr_index(struct ifile *p, int incr)
55 {
56 for (; p != &anchor; p = p->h_next)
57 p->h_index += incr;
58 }
59
60 /*
61 * Link an ifile into the ifile list.
62 */
link_ifile(struct ifile * p,struct ifile * prev)63 static void link_ifile(struct ifile *p, struct ifile *prev)
64 {
65 /*
66 * Link into list.
67 */
68 if (prev == NULL)
69 prev = &anchor;
70 p->h_next = prev->h_next;
71 p->h_prev = prev;
72 prev->h_next->h_prev = p;
73 prev->h_next = p;
74 /*
75 * Calculate index for the new one,
76 * and adjust the indexes for subsequent ifiles in the list.
77 */
78 p->h_index = prev->h_index + 1;
79 incr_index(p->h_next, 1);
80 ifiles++;
81 }
82
83 /*
84 * Unlink an ifile from the ifile list.
85 */
unlink_ifile(struct ifile * p)86 static void unlink_ifile(struct ifile *p)
87 {
88 p->h_next->h_prev = p->h_prev;
89 p->h_prev->h_next = p->h_next;
90 incr_index(p->h_next, -1);
91 ifiles--;
92 }
93
94 /*
95 * Allocate a new ifile structure and stick a filename in it.
96 * It should go after "prev" in the list
97 * (or at the beginning of the list if "prev" is NULL).
98 * Return a pointer to the new ifile structure.
99 */
new_ifile(constant char * filename,struct ifile * prev)100 static struct ifile * new_ifile(constant char *filename, struct ifile *prev)
101 {
102 struct ifile *p;
103
104 /*
105 * Allocate and initialize structure.
106 */
107 p = (struct ifile *) ecalloc(1, sizeof(struct ifile));
108 p->h_filename = save(filename);
109 p->h_rfilename = lrealpath(filename);
110 p->h_scrpos.pos = NULL_POSITION;
111 p->h_opened = 0;
112 p->h_hold = 0;
113 p->h_filestate = NULL;
114 p->h_altfilename = NULL;
115 p->h_altpipe = NULL;
116 link_ifile(p, prev);
117 /*
118 * {{ It's dodgy to call mark.c functions from here;
119 * there is potentially dangerous recursion.
120 * Probably need to revisit this design. }}
121 */
122 mark_check_ifile(ext_ifile(p));
123 return (p);
124 }
125
126 /*
127 * Delete an existing ifile structure.
128 */
del_ifile(IFILE h)129 public void del_ifile(IFILE h)
130 {
131 struct ifile *p;
132
133 if (h == NULL_IFILE)
134 return;
135 /*
136 * If the ifile we're deleting is the currently open ifile,
137 * move off it.
138 */
139 unmark(h);
140 if (h == curr_ifile)
141 curr_ifile = getoff_ifile(curr_ifile);
142 p = int_ifile(h);
143 unlink_ifile(p);
144 free(p->h_rfilename);
145 free(p->h_filename);
146 free(p);
147 }
148
149 /*
150 * Get the ifile after a given one in the list.
151 */
next_ifile(IFILE h)152 public IFILE next_ifile(IFILE h)
153 {
154 struct ifile *p;
155
156 p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
157 if (p->h_next == &anchor)
158 return (NULL_IFILE);
159 return (ext_ifile(p->h_next));
160 }
161
162 /*
163 * Get the ifile before a given one in the list.
164 */
prev_ifile(IFILE h)165 public IFILE prev_ifile(IFILE h)
166 {
167 struct ifile *p;
168
169 p = (h == NULL_IFILE) ? &anchor : int_ifile(h);
170 if (p->h_prev == &anchor)
171 return (NULL_IFILE);
172 return (ext_ifile(p->h_prev));
173 }
174
175 /*
176 * Return a different ifile from the given one.
177 */
getoff_ifile(IFILE ifile)178 public IFILE getoff_ifile(IFILE ifile)
179 {
180 IFILE newifile;
181
182 if ((newifile = prev_ifile(ifile)) != NULL_IFILE)
183 return (newifile);
184 if ((newifile = next_ifile(ifile)) != NULL_IFILE)
185 return (newifile);
186 return (NULL_IFILE);
187 }
188
189 /*
190 * Return the number of ifiles.
191 */
nifile(void)192 public int nifile(void)
193 {
194 return (ifiles);
195 }
196
197 /*
198 * Find an ifile structure, given a filename.
199 */
find_ifile(constant char * filename)200 static struct ifile * find_ifile(constant char *filename)
201 {
202 struct ifile *p;
203 char *rfilename = lrealpath(filename);
204
205 for (p = anchor.h_next; p != &anchor; p = p->h_next)
206 {
207 if (strcmp(rfilename, p->h_rfilename) == 0)
208 {
209 /*
210 * If given name is shorter than the name we were
211 * previously using for this file, adopt shorter name.
212 */
213 if (strlen(filename) < strlen(p->h_filename))
214 {
215 free(p->h_filename);
216 p->h_filename = save(filename);
217 }
218 break;
219 }
220 }
221 free(rfilename);
222 if (p == &anchor)
223 p = NULL;
224 return (p);
225 }
226
227 /*
228 * Get the ifile associated with a filename.
229 * If the filename has not been seen before,
230 * insert the new ifile after "prev" in the list.
231 */
get_ifile(constant char * filename,IFILE prev)232 public IFILE get_ifile(constant char *filename, IFILE prev)
233 {
234 struct ifile *p;
235
236 if ((p = find_ifile(filename)) == NULL)
237 p = new_ifile(filename, int_ifile(prev));
238 return (ext_ifile(p));
239 }
240
241 /*
242 * Get the display filename associated with a ifile.
243 */
get_filename(IFILE ifile)244 public constant char * get_filename(IFILE ifile)
245 {
246 if (ifile == NULL)
247 return (NULL);
248 return (int_ifile(ifile)->h_filename);
249 }
250
251 /*
252 * Get the canonical filename associated with a ifile.
253 */
get_real_filename(IFILE ifile)254 public constant char * get_real_filename(IFILE ifile)
255 {
256 if (ifile == NULL)
257 return (NULL);
258 return (int_ifile(ifile)->h_rfilename);
259 }
260
261 /*
262 * Get the index of the file associated with a ifile.
263 */
get_index(IFILE ifile)264 public int get_index(IFILE ifile)
265 {
266 return (int_ifile(ifile)->h_index);
267 }
268
269 /*
270 * Save the file position to be associated with a given file.
271 */
store_pos(IFILE ifile,struct scrpos * scrpos)272 public void store_pos(IFILE ifile, struct scrpos *scrpos)
273 {
274 int_ifile(ifile)->h_scrpos = *scrpos;
275 }
276
277 /*
278 * Recall the file position associated with a file.
279 * If no position has been associated with the file, return NULL_POSITION.
280 */
get_pos(IFILE ifile,struct scrpos * scrpos)281 public void get_pos(IFILE ifile, struct scrpos *scrpos)
282 {
283 *scrpos = int_ifile(ifile)->h_scrpos;
284 }
285
286 /*
287 * Mark the ifile as "opened".
288 */
set_open(IFILE ifile)289 public void set_open(IFILE ifile)
290 {
291 int_ifile(ifile)->h_opened = 1;
292 }
293
294 /*
295 * Return whether the ifile has been opened previously.
296 */
opened(IFILE ifile)297 public int opened(IFILE ifile)
298 {
299 return (int_ifile(ifile)->h_opened);
300 }
301
hold_ifile(IFILE ifile,int incr)302 public void hold_ifile(IFILE ifile, int incr)
303 {
304 int_ifile(ifile)->h_hold += incr;
305 }
306
held_ifile(IFILE ifile)307 public int held_ifile(IFILE ifile)
308 {
309 return (int_ifile(ifile)->h_hold);
310 }
311
get_filestate(IFILE ifile)312 public void * get_filestate(IFILE ifile)
313 {
314 return (int_ifile(ifile)->h_filestate);
315 }
316
set_filestate(IFILE ifile,void * filestate)317 public void set_filestate(IFILE ifile, void *filestate)
318 {
319 int_ifile(ifile)->h_filestate = filestate;
320 }
321
set_altpipe(IFILE ifile,void * p)322 public void set_altpipe(IFILE ifile, void *p)
323 {
324 int_ifile(ifile)->h_altpipe = p;
325 }
326
get_altpipe(IFILE ifile)327 public void *get_altpipe(IFILE ifile)
328 {
329 return (int_ifile(ifile)->h_altpipe);
330 }
331
set_altfilename(IFILE ifile,char * altfilename)332 public void set_altfilename(IFILE ifile, char *altfilename)
333 {
334 struct ifile *p = int_ifile(ifile);
335 if (p->h_altfilename != NULL && p->h_altfilename != altfilename)
336 free(p->h_altfilename);
337 p->h_altfilename = altfilename;
338 }
339
340 /*
341 * Not constant; caller can free altfilename.
342 * {{ This is poor design and should be changed. }}
343 */
get_altfilename(IFILE ifile)344 public char * get_altfilename(IFILE ifile)
345 {
346 return (int_ifile(ifile)->h_altfilename);
347 }
348
349 #if 0
350 public void if_dump(void)
351 {
352 struct ifile *p;
353
354 for (p = anchor.h_next; p != &anchor; p = p->h_next)
355 {
356 printf("%x: %d. <%s> pos %d,%x\n",
357 p, p->h_index, p->h_filename,
358 p->h_scrpos.ln, p->h_scrpos.pos);
359 ch_dump(p->h_filestate);
360 }
361 }
362 #endif
363