Initial commit.

Makefile

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+# Makefile for symlinks
+
+CC = gcc
+ 
+all: symlinks
+
+symlinks: symlinks.c
+	$(CC) -Wall -Wstrict-prototypes -O2 ${CFLAGS} -o symlinks symlinks.c
+ 
+install: all symlinks.8
+	install -m 755 -o root -g root symlinks /usr/local/bin
+	install -m 644 -o root -g root symlinks.8 /usr/local/man/man8
+
+clean:
+	rm -f symlinks *.o core

symlinks.8

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+.TH SYMLINKS 8 "October 2008" "Version 1.4"
+
+.SH NAME
+symlinks \- symbolic link maintenance utility
+.SH SYNOPSIS
+.B symlinks
+[
+.B -cdorstv
+]
+dirlist
+.SH DESCRIPTION
+.BI symlinks
+is a useful utility for maintainers of FTP sites, CDROMs,
+and Linux software distributions.
+It scans directories for symbolic links and lists them on stdout,
+often revealing flaws in the filesystem tree.
+.PP
+Each link is output with a classification of
+.B relative,
+.B absolute,
+.B dangling,
+.B messy,
+.B lengthy,
+or
+.B other_fs.
+.PP
+.B relative
+links are those expressed as paths relative to the directory in which
+the links reside, usually independent of the mount point of the filesystem.
+.PP
+.B absolute
+links are those given as an absolute path from the root directory
+as indicated by a leading slash (/).
+.PP
+.B dangling
+links are those for which the target of the link does not currently exist.
+This commonly occurs for
+.B absolute
+links when a filesystem is mounted at other than its
+customary mount point (such as when the normal root filesystem is
+mounted at /mnt after booting from alternative media).
+.PP
+.B messy
+links are links which contain unnecessary slashes or dots in the path.
+These are cleaned up as well when
+.B -c
+is specified.
+.PP
+.B lengthy
+links are links which use "../" more than necessary in the path
+(eg.  /bin/vi -> ../bin/vim)
+These are only detected when
+.B -s
+is specified, and are only cleaned up when
+.B -c
+is also specified.
+.PP
+.B other_fs
+are those links whose target currently resides on a different filesystem
+from where symlinks was run (most useful with
+.B -r
+).
+.PP
+.SH OPTIONS
+.TP
+.I -c 
+convert absolute links (within the same filesystem) to relative links.
+This permits links to maintain their validity regardless of the mount
+point used for the filesystem -- a desirable setup in most cases.
+This option also causes any
+.B messy
+links to be cleaned up, and, if
+.B -s
+was also specified, then
+.B lengthy
+links are also shortened.
+Links affected by
+.B -c
+are prefixed with
+.B changed
+in the output.
+.TP
+.I -d
+causes
+.B dangling
+links to be removed.
+.TP
+.I -o 
+fix links on other filesystems encountered while recursing.
+Normally, other filesystems encountered are not modified by symlinks.
+.TP
+.I -r 
+recursively operate on subdirectories within the same filesystem.
+.TP
+.I -s
+causes
+.B lengthy
+links to be detected.
+.TP
+.I -t
+is used to test for what
+.B symlinks
+would do if
+.B -c
+were specified, but without really changing anything.
+.TP
+.I -v 
+show all symbolic links.  By default, 
+.B relative
+links are not shown unless 
+.B -v
+is specified.
+.PP
+.SH BUGS
+.B symlinks
+does not recurse or change links across filesystems.
+.PP
+.SH AUTHOR
+.B symlinks 
+has been written by Mark Lord <mlord@pobox.com>, the original developer and maintainer
+of the IDE Performance Package for linux, the Linux IDE Driver subsystem, hdparm, and a current day libata hacker.
+.SH SEE ALSO
+.BR symlink (2)

symlinks.c

@@ -0,0 +1,362 @@
+#include <unistd.h>
+#ifndef _POSIX_SOURCE
+#define _POSIX_SOURCE
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <time.h>
+#include <stddef.h>
+#include <errno.h>
+
+#ifndef S_ISLNK
+#define S_ISLNK(mode) (((mode) & (_S_IFMT)) == (_S_IFLNK))
+#endif
+
+#ifndef PATH_MAX
+#define PATH_MAX 1024
+#endif
+
+#define progver "%s: scan/change symbolic links - v1.3 - by Mark Lord\n\n"
+static char *progname;
+static int verbose = 0, fix_links = 0, recurse = 0, delete = 0, shorten = 0,
+		testing = 0, single_fs = 1;
+
+/*
+ * tidypath removes excess slashes and "." references from a path string
+ */
+
+static int substr (char *s, char *old, char *new)
+{
+	char *tmp = NULL;
+	int oldlen = strlen(old), newlen = 0;
+
+	if (NULL == strstr(s, old))
+		return 0;
+
+	if (new)
+		newlen = strlen(new);
+
+	if (newlen > oldlen) {
+		if ((tmp = malloc(strlen(s))) == NULL) {
+			fprintf(stderr, "no memory\n");
+			exit (1);
+		}
+	}
+
+	while (NULL != (s = strstr(s, old))) {
+		char *p, *old_s = s;
+
+		if (new) {
+			if (newlen > oldlen)
+				old_s = strcpy(tmp, s);
+			p = new;
+			while (*p)
+				*s++ = *p++;
+		}
+		p = old_s + oldlen;
+		while ((*s++ = *p++));
+	}
+	if (tmp)
+		free(tmp);
+	return 1;
+}
+
+
+static int tidy_path (char *path)
+{
+	int tidied = 0;
+	char *s, *p;
+
+	s = path + strlen(path) - 1;
+	if (s[0] != '/') {	/* tmp trailing slash simplifies things */
+		s[1] = '/';
+		s[2] = '\0';
+	}
+	while (substr(path, "/./", "/"))
+		tidied = 1;
+	while (substr(path, "//", "/"))
+		tidied = 1;
+
+	while ((p = strstr(path,"/../")) != NULL) {
+		s = p+3;
+		for (p--; p != path; p--) if (*p == '/') break;
+		if (*p != '/')
+			break;
+		while ((*p++ = *s++));
+		tidied = 1;
+	}
+	if (*path == '\0')
+		strcpy(path,"/");
+	p = path + strlen(path) - 1;
+	if (p != path && *p == '/')
+		*p-- = '\0';	/* remove tmp trailing slash */
+	while (p != path && *p == '/') {	/* remove any others */
+		*p-- = '\0';
+		tidied = 1;
+	}
+	while (!strncmp(path,"./",2)) {
+		for (p = path, s = path+2; (*p++ = *s++););
+		tidied = 1;
+	}
+	return tidied;
+}
+
+static int shorten_path (char *path, char *abspath)
+{
+	static char dir[PATH_MAX];
+	int shortened = 0;
+	char *p;
+
+	/* get rid of unnecessary "../dir" sequences */
+	while (abspath && strlen(abspath) > 1 && (p = strstr(path,"../"))) {
+		/* find innermost occurance of "../dir", and save "dir" */
+		int slashes = 2;
+		char *a, *s, *d = dir;
+		while ((s = strstr(p+3, "../"))) {
+			++slashes;
+			p = s;
+		}
+		s = p+3;
+		*d++ = '/';
+		while (*s && *s != '/')
+			*d++ = *s++;
+		*d++ = '/';
+		*d = '\0';
+		if (!strcmp(dir,"//"))
+			break;
+		/* note: p still points at ../dir */
+		if (*s != '/' || !*++s)
+			break;
+		a = abspath + strlen(abspath) - 1;
+		while (slashes-- > 0) {
+			if (a <= abspath)
+				goto ughh;
+			while (*--a != '/') {
+				if (a <= abspath)
+					goto ughh;
+			}
+		}
+		if (strncmp(dir, a, strlen(dir)))
+			break;
+		while ((*p++ = *s++)); /* delete the ../dir */
+		shortened = 1;
+	}
+ughh:
+	return shortened;
+}
+
+
+static void fix_symlink (char *path, dev_t my_dev)
+{
+	static char lpath[PATH_MAX], new[PATH_MAX], abspath[PATH_MAX];
+	char *p, *np, *lp, *tail, *msg;
+	struct stat stbuf, lstbuf;
+	int c, fix_abs = 0, fix_messy = 0, fix_long = 0;
+
+	if ((c = readlink(path, lpath, sizeof(lpath))) == -1) {
+		perror(path);
+		return;
+	}
+	lpath[c] = '\0';	/* readlink does not null terminate it */
+
+	/* construct the absolute address of the link */
+	abspath[0] = '\0';
+	if (lpath[0] != '/') {
+		strcat(abspath,path);
+		c = strlen(abspath);
+		if ((c > 0) && (abspath[c-1] == '/'))
+			abspath[c-1] = '\0'; /* cut trailing / */
+		if ((p = strrchr(abspath,'/')) != NULL)
+			*p = '\0'; /* cut last component */
+		strcat(abspath,"/");
+	}
+	strcat(abspath,lpath);
+	(void) tidy_path(abspath);
+
+	/* check for various things */
+	if (stat(abspath, &stbuf) == -1) {
+		printf("dangling: %s -> %s\n", path, lpath);
+		if (delete) {
+			if (unlink (path)) {
+				perror(path); 
+			} else
+				printf("deleted:  %s -> %s\n", path, lpath);
+		}
+		return;
+	}
+
+	if (single_fs)
+		lstat(abspath, &lstbuf); /* if the above didn't fail, then this shouldn't */
+	
+	if (single_fs && lstbuf.st_dev != my_dev) {
+		msg = "other_fs:";
+	} else if (lpath[0] == '/') {
+		msg = "absolute:";
+		fix_abs = 1;
+	} else if (verbose) {
+		msg = "relative:";
+	} else
+		msg = NULL;
+	fix_messy = tidy_path(strcpy(new,lpath));
+	if (shorten)
+		fix_long = shorten_path(new, path);
+	if (!fix_abs) {
+		if (fix_messy)
+			msg = "messy:   ";
+		else if (fix_long)
+			msg = "lengthy: ";
+	}
+	if (msg != NULL)
+		printf("%s %s -> %s\n", msg, path, lpath);
+	if (!(fix_links || testing) || !(fix_messy || fix_abs || fix_long))
+		return;
+
+	if (fix_abs) {
+		/* convert an absolute link to relative: */
+		/* point tail at first part of lpath that differs from path */
+		/* point p    at first part of path  that differs from lpath */
+		(void) tidy_path(lpath);
+		tail = lp = lpath;
+		p = path;
+		while (*p && (*p == *lp)) {
+			if (*lp++ == '/') {
+				tail = lp;
+				while (*++p == '/');
+			}
+		}
+
+		/* now create new, with "../"s followed by tail */
+		np = new;
+		while (*p) {
+			if (*p++ == '/') {
+				*np++ = '.';
+				*np++ = '.';
+				*np++ = '/';
+				while (*p == '/') ++p;
+			}
+		}
+		strcpy (np, tail);
+		(void) tidy_path(new);
+		if (shorten) (void) shorten_path(new, path);
+	}
+	shorten_path(new,path);
+	if (!testing) {
+		if (unlink (path)) {
+			perror(path);
+			return;
+		}
+		if (symlink(new, path)) {
+			perror(path);
+			return;
+		}
+	}
+	printf("changed:  %s -> %s\n", path, new);
+}
+
+static void dirwalk (char *path, int pathlen, dev_t dev)
+{
+ 	char *name;
+	DIR *dfd;
+	static struct stat st;
+	static struct dirent *dp;
+
+	if ((dfd = opendir(path)) == NULL) {
+		perror(path);
+		return;
+	}
+
+	name = path + pathlen;
+	if (*(name-1) != '/')
+		*name++ = '/'; 
+
+	while ((dp = readdir(dfd)) != NULL ) {
+		strcpy(name, dp->d_name);
+                if (strcmp(name, ".") && strcmp(name,"..")) {
+			if (lstat(path, &st) == -1) {
+				perror(path);
+			} else if (st.st_dev == dev) {
+				if (S_ISLNK(st.st_mode)) {
+					fix_symlink (path, dev);
+				} else if (recurse && S_ISDIR(st.st_mode)) {
+					dirwalk(path, strlen(path), dev);
+				}
+			}
+		}
+	} 
+	closedir(dfd);
+	path[pathlen] = '\0';
+}
+
+static void usage_error (void)
+{
+	fprintf(stderr, progver, progname);
+	fprintf(stderr, "Usage:\t%s [-cdorstv] dirlist\n\n", progname);
+	fprintf(stderr, "Flags:"
+		"\t-c == change absolute/messy links to relative\n"
+		"\t-d == delete dangling links\n"
+		"\t-o == warn about links across file systems\n"
+		"\t-r == recurse into subdirs\n"
+		"\t-s == shorten lengthy links (displayed in output only when -c not specified)\n"
+		"\t-t == show what would be done by -c\n"
+		"\t-v == verbose (show all symlinks)\n\n");
+	exit(1);
+}
+
+int main(int argc, char **argv)
+{
+	static char path[PATH_MAX+2], cwd[PATH_MAX+2];
+	int dircount = 0;
+	char c, *p;
+
+	if  ((progname = (char *) strrchr(*argv, '/')) == NULL)
+                progname = *argv;
+        else
+                progname++;
+
+	if (NULL == getcwd(cwd,PATH_MAX)) {
+		fprintf(stderr,"getcwd() failed\n");
+		exit (1);
+	}
+	if (!*cwd || cwd[strlen(cwd)-1] != '/')
+		strcat(cwd,"/");
+
+	while (--argc) {
+		p = *++argv;
+		if (*p == '-') {
+			if (*++p == '\0')
+				usage_error();
+			while ((c = *p++)) {
+				     if (c == 'c')	fix_links = 1;
+				else if (c == 'd')	delete    = 1;
+				else if (c == 'o')	single_fs = 0;
+				else if (c == 'r')	recurse   = 1;
+				else if (c == 's')	shorten   = 1;
+				else if (c == 't')	testing   = 1;
+				else if (c == 'v')	verbose   = 1;
+				else			usage_error();
+			}
+		} else {
+			struct stat st;
+			if (*p == '/')
+				*path = '\0';
+			else
+				strcpy(path,cwd);
+			tidy_path(strcat(path, p));
+			if (lstat(path, &st) == -1)
+				perror(path);
+			else
+				dirwalk(path, strlen(path), st.st_dev);
+			++dircount;
+		}
+	}
+	if (dircount == 0)
+		usage_error();
+	exit (0);
+}

symlinks.lsm

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+Begin2
+Title        =symlinks - scan/change symbolic links
+Version      =1.4
+Desc1        =Scans directories for symbolic links, and identifies dangling,
+Desc2        =relative, absolute, messy, and other_fs links.  Can optionally
+Desc3        =change absolute links to relative within a given filesystem.
+Desc4        =Recommended for use by anyone developing and/or maintaining
+Desc5        =a Linux FTP site or distribution or CD-ROM.
+Author       =Mark Lord
+AuthorEmail  =mlord@pobox.com
+Maintainer   =Mark Lord
+MaintEmail   =mlord@pobox.com
+Site1        =tsx-11.mit.edu
+Path1        =/pub/linux/sources/usr.bin
+File1        =symlinks-1.4.tar.gz
+FileSize1    =5KB
+Required1    =
+Required2    =
+Required3    =
+Required4    =
+CopyPolicy1  =(c) Mark Lord, freely distributable
+CopyPolicy2  =
+Keywords     =symbolic links cd cdrom CD-ROM distribution
+Comment1     =v1.4 incorporate patches from Fedora
+Comment1     =v1.3 more messy-link fixes, new -o flag for other_fs
+Comment2     =v1.2 added -s flag to shorten links with redundant
+Comment3     =path elements.  Also includes code to remove excess
+Comment4     =slashes from paths.
+RelFiles1    =
+RelFiles2    =
+RelFiles3    =
+Entered      =09OCT2009
+EnteredBy    =Mark Lord
+CheckedEmail =mlord@pobox.com
+End
+