diff options
Diffstat (limited to 'ifile.c')
| -rwxr-xr-x | ifile.c | 345 |
1 files changed, 345 insertions, 0 deletions
@@ -0,0 +1,345 @@ +/* + * Copyright (C) 1984-2012 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 */ + 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 */ +}; + +/* + * 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)) + +/* + * Anchor for linked list. + */ +static struct ifile anchor = { &anchor, &anchor, NULL, NULL, 0, 0, '\0', + { NULL_POSITION, 0 } }; +static int ifiles = 0; + + static void +incr_index(p, incr) + register 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(p, prev) + 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(p) + 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(filename, prev) + char *filename; + struct ifile *prev; +{ + register struct ifile *p; + + /* + * Allocate and initialize structure. + */ + p = (struct ifile *) ecalloc(1, sizeof(struct ifile)); + p->h_filename = save(filename); + p->h_scrpos.pos = NULL_POSITION; + p->h_opened = 0; + p->h_hold = 0; + p->h_filestate = NULL; + link_ifile(p, prev); + return (p); +} + +/* + * Delete an existing ifile structure. + */ + public void +del_ifile(h) + IFILE h; +{ + register 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_filename); + free(p); +} + +/* + * Get the ifile after a given one in the list. + */ + public IFILE +next_ifile(h) + IFILE h; +{ + register 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(h) + IFILE h; +{ + register 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; +{ + 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() +{ + return (ifiles); +} + +/* + * Find an ifile structure, given a filename. + */ + static struct ifile * +find_ifile(filename) + char *filename; +{ + register struct ifile *p; + + for (p = anchor.h_next; p != &anchor; p = p->h_next) + if (strcmp(filename, p->h_filename) == 0) + return (p); + return (NULL); +} + +/* + * 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(filename, prev) + char *filename; + IFILE prev; +{ + register struct ifile *p; + + if ((p = find_ifile(filename)) == NULL) + p = new_ifile(filename, int_ifile(prev)); + return (ext_ifile(p)); +} + +/* + * Get the filename associated with a ifile. + */ + public char * +get_filename(ifile) + IFILE ifile; +{ + if (ifile == NULL) + return (NULL); + return (int_ifile(ifile)->h_filename); +} + +/* + * Get the index of the file associated with a ifile. + */ + public int +get_index(ifile) + IFILE ifile; +{ + return (int_ifile(ifile)->h_index); +} + +/* + * Save the file position to be associated with a given file. + */ + public void +store_pos(ifile, scrpos) + 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, scrpos) + IFILE ifile; + struct scrpos *scrpos; +{ + *scrpos = int_ifile(ifile)->h_scrpos; +} + +/* + * Mark the ifile as "opened". + */ + public void +set_open(ifile) + IFILE ifile; +{ + int_ifile(ifile)->h_opened = 1; +} + +/* + * Return whether the ifile has been opened previously. + */ + public int +opened(ifile) + IFILE ifile; +{ + return (int_ifile(ifile)->h_opened); +} + + public void +hold_ifile(ifile, incr) + IFILE ifile; + int incr; +{ + int_ifile(ifile)->h_hold += incr; +} + + public int +held_ifile(ifile) + IFILE ifile; +{ + return (int_ifile(ifile)->h_hold); +} + + public void * +get_filestate(ifile) + IFILE ifile; +{ + return (int_ifile(ifile)->h_filestate); +} + + public void +set_filestate(ifile, filestate) + IFILE ifile; + void *filestate; +{ + int_ifile(ifile)->h_filestate = filestate; +} + +#if 0 + public void +if_dump() +{ + register struct ifile *p; + + for (p = anchor.h_next; p != &anchor; p = p->h_next) + { + printf("%x: %d. <%s> pos %d,%x\n", + p, p->h_index, p->h_filename, + p->h_scrpos.ln, p->h_scrpos.pos); + ch_dump(p->h_filestate); + } +} +#endif |