Import sources from 2011-03-30 iso image

1 files changed, 320 insertions, 0 deletions

diff --git a/sys/src/ape/cmd/pax/link.c b/sys/src/ape/cmd/pax/link.c
new file mode 100755
index 000000000..d7e739a7a
--- /dev/null
+++ b/sys/src/ape/cmd/pax/link.c
@@ -0,0 +1,320 @@
+/* $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)");
+	    }
+	}
+    }
+}