1 /* 2 * Copyright (C) 1984-2023 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 } }; 52 static int ifiles = 0; 53 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 */ 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 */ 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 */ 100 static struct ifile * new_ifile(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 */ 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 */ 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 */ 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 */ 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 */ 192 public int nifile(void) 193 { 194 return (ifiles); 195 } 196 197 /* 198 * Find an ifile structure, given a filename. 199 */ 200 static struct ifile * find_ifile(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 */ 232 public IFILE get_ifile(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 */ 244 public 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 */ 254 public 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 */ 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 */ 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 */ 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 */ 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 */ 297 public int opened(IFILE ifile) 298 { 299 return (int_ifile(ifile)->h_opened); 300 } 301 302 public void hold_ifile(IFILE ifile, int incr) 303 { 304 int_ifile(ifile)->h_hold += incr; 305 } 306 307 public int held_ifile(IFILE ifile) 308 { 309 return (int_ifile(ifile)->h_hold); 310 } 311 312 public void * get_filestate(IFILE ifile) 313 { 314 return (int_ifile(ifile)->h_filestate); 315 } 316 317 public void set_filestate(IFILE ifile, void *filestate) 318 { 319 int_ifile(ifile)->h_filestate = filestate; 320 } 321 322 public void set_altpipe(IFILE ifile, void *p) 323 { 324 int_ifile(ifile)->h_altpipe = p; 325 } 326 327 public void *get_altpipe(IFILE ifile) 328 { 329 return (int_ifile(ifile)->h_altpipe); 330 } 331 332 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 public char * get_altfilename(IFILE ifile) 341 { 342 return (int_ifile(ifile)->h_altfilename); 343 } 344 345 #if 0 346 public void if_dump(void) 347 { 348 struct ifile *p; 349 350 for (p = anchor.h_next; p != &anchor; p = p->h_next) 351 { 352 printf("%x: %d. <%s> pos %d,%x\n", 353 p, p->h_index, p->h_filename, 354 p->h_scrpos.ln, p->h_scrpos.pos); 355 ch_dump(p->h_filestate); 356 } 357 } 358 #endif 359