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- /* $Source: /u/mark/src/pax/RCS/link.c,v $
- *
- * $Revision: 1.2 $
- *
- * link.c - functions for handling multiple file links
- *
- * DESCRIPTION
- *
- * These function manage the link chains which are used to keep track
- * of outstanding links during archive reading and writing.
- *
- * AUTHOR
- *
- * Mark H. Colburn, NAPS International (mark@jhereg.mn.org)
- *
- * Sponsored by The USENIX Association for public distribution.
- *
- * Copyright (c) 1989 Mark H. Colburn.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms are permitted
- * provided that the above copyright notice is duplicated in all such
- * forms and that any documentation, advertising materials, and other
- * materials related to such distribution and use acknowledge that the
- * software was developed * by Mark H. Colburn and sponsored by The
- * USENIX Association.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- *
- * $Log: link.c,v $
- * Revision 1.2 89/02/12 10:04:38 mark
- * 1.2 release fixes
- *
- * Revision 1.1 88/12/23 18:02:12 mark
- * Initial revision
- *
- */
- #ifndef lint
- static char *ident = "$Id: link.c,v 1.2 89/02/12 10:04:38 mark Exp $";
- static char *copyright = "Copyright (c) 1989 Mark H. Colburn.\nAll rights reserved.\n";
- #endif /* ! lint */
- /* Headers */
- #include "pax.h"
- /* Defines */
- /*
- * Address link information base.
- */
- #define LINKHASH(ino) (linkbase + (ino) % NEL(linkbase))
- /*
- * Number of array elements.
- */
- #define NEL(a) (sizeof(a) / sizeof(*(a)))
- /* Internal Identifiers */
- static Link *linkbase[256]; /* Unresolved link information */
- /* linkfrom - find a file to link from
- *
- * DESCRIPTION
- *
- * Linkfrom searches the link chain to see if there is a file in the
- * link chain which has the same inode number as the file specified
- * by the stat block pointed at by asb. If a file is found, the
- * name is returned to the caller, otherwise a NULL is returned.
- *
- * PARAMETERS
- *
- * char *name - name of the file which we are attempting
- * to find a link for
- * Stat *asb - stat structure of file to find a link to
- *
- * RETURNS
- *
- * Returns a pointer to a link structure, or NULL if unsuccessful.
- *
- */
- #ifdef __STDC__
- Link *linkfrom(char *name, Stat *asb)
- #else
-
- Link *linkfrom(name, asb)
- char *name;
- Stat *asb;
- #endif
- {
- Link *linkp;
- Link *linknext;
- Path *path;
- Path *pathnext;
- Link **abase;
- for (linkp = *(abase = LINKHASH(asb->sb_ino)); linkp; linkp = linknext) {
- if (linkp->l_nlink == 0) {
- if (linkp->l_name) {
- free((char *) linkp->l_name);
- }
- if (linknext = linkp->l_forw) {
- linknext->l_back = linkp->l_back;
- }
- if (linkp->l_back) {
- linkp->l_back->l_forw = linkp->l_forw;
- }
- free((char *) linkp);
- *abase = (Link *)NULL;
- } else if (linkp->l_ino == asb->sb_ino && linkp->l_dev == asb->sb_dev) {
- /*
- * check to see if a file with the name "name" exists in the
- * chain of files which we have for this particular link
- */
- for (path = linkp->l_path; path; path = pathnext) {
- if (strcmp(path->p_name, name) == 0) {
- --linkp->l_nlink;
- if (path->p_name) {
- free(path->p_name);
- }
- if (pathnext = path->p_forw) {
- pathnext->p_back = path->p_back;
- }
- if (path->p_back) {
- path->p_back->p_forw = pathnext;
- }
- if (linkp->l_path == path) {
- linkp->l_path = pathnext;
- }
- free(path);
- return (linkp);
- }
- pathnext = path->p_forw;
- }
- return((Link *)NULL);
- } else {
- linknext = linkp->l_forw;
- }
- }
- return ((Link *)NULL);
- }
- /* islink - determine whether a given file really a link
- *
- * DESCRIPTION
- *
- * Islink searches the link chain to see if there is a file in the
- * link chain which has the same inode number as the file specified
- * by the stat block pointed at by asb. If a file is found, a
- * non-zero value is returned to the caller, otherwise a 0 is
- * returned.
- *
- * PARAMETERS
- *
- * char *name - name of file to check to see if it is link.
- * Stat *asb - stat structure of file to find a link to
- *
- * RETURNS
- *
- * Returns a pointer to a link structure, or NULL if unsuccessful.
- *
- */
- #ifdef __STDC__
- Link *islink(char *name, Stat *asb)
- #else
-
- Link *islink(name, asb)
- char *name;
- Stat *asb;
- #endif
- {
- Link *linkp;
- Link *linknext;
- for (linkp = *(LINKHASH(asb->sb_ino)); linkp; linkp = linknext) {
- if (linkp->l_ino == asb->sb_ino && linkp->l_dev == asb->sb_dev) {
- if (strcmp(name, linkp->l_name) == 0) {
- return ((Link *)NULL);
- }
- return (linkp);
- } else {
- linknext = linkp->l_forw;
- }
- }
- return ((Link *)NULL);
- }
- /* linkto - remember a file with outstanding links
- *
- * DESCRIPTION
- *
- * Linkto adds the specified file to the link chain. Any subsequent
- * calls to linkfrom which have the same inode will match the file
- * just entered. If not enough space is available to make the link
- * then the item is not added to the link chain, and a NULL is
- * returned to the calling function.
- *
- * PARAMETERS
- *
- * char *name - name of file to remember
- * Stat *asb - pointer to stat structure of file to remember
- *
- * RETURNS
- *
- * Returns a pointer to the associated link structure, or NULL when
- * linking is not possible.
- *
- */
- #ifdef __STDC__
- Link *linkto(char *name, Stat *asb)
- #else
-
- Link *linkto(name, asb)
- char *name;
- Stat *asb;
- #endif
- {
- Link *linkp;
- Link *linknext;
- Path *path;
- Link **abase;
- for (linkp = *(LINKHASH(asb->sb_ino)); linkp; linkp = linknext) {
- if (linkp->l_ino == asb->sb_ino && linkp->l_dev == asb->sb_dev) {
- if ((path = (Path *) mem_get(sizeof(Path))) == (Path *)NULL ||
- (path->p_name = mem_str(name)) == (char *)NULL) {
- return((Link *)NULL);
- }
- if (path->p_forw = linkp->l_path) {
- if (linkp->l_path->p_forw) {
- linkp->l_path->p_forw->p_back = path;
- }
- } else {
- linkp->l_path = path;
- }
- path->p_back = (Path *)NULL;
- return(linkp);
- } else {
- linknext = linkp->l_forw;
- }
- }
- /*
- * This is a brand new link, for which there is no other information
- */
- if ((asb->sb_mode & S_IFMT) == S_IFDIR
- || (linkp = (Link *) mem_get(sizeof(Link))) == (Link *)NULL
- || (linkp->l_name = mem_str(name)) == (char *)NULL) {
- return ((Link *)NULL);
- }
- linkp->l_dev = asb->sb_dev;
- linkp->l_ino = asb->sb_ino;
- linkp->l_nlink = asb->sb_nlink - 1;
- linkp->l_size = asb->sb_size;
- linkp->l_path = (Path *)NULL;
- if (linkp->l_forw = *(abase = LINKHASH(asb->sb_ino))) {
- linkp->l_forw->l_back = linkp;
- } else {
- *abase = linkp;
- }
- linkp->l_back = (Link *)NULL;
- return (linkp);
- }
- /* linkleft - complain about files with unseen links
- *
- * DESCRIPTION
- *
- * Linksleft scans through the link chain to see if there were any
- * files which have outstanding links that were not processed by the
- * archive. For each file in the link chain for which there was not
- * a file, and error message is printed.
- */
- #ifdef __STDC__
- void linkleft(void)
- #else
-
- void linkleft()
- #endif
- {
- Link *lp;
- Link **base;
- for (base = linkbase; base < linkbase + NEL(linkbase); ++base) {
- for (lp = *base; lp; lp = lp->l_forw) {
- if (lp->l_nlink) {
- warn(lp->l_path->p_name, "Unseen link(s)");
- }
- }
- }
- }
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