cdio_follow_symlink -> cdio_realpath which is really POSIX realpath. (Suggestion via Thomas Schmitt.) gnu_linux.c: report errors when they occur.

configure.ac

@@ -491,7 +491,7 @@ AC_SUBST(LIBCDIO_SOURCE_PATH)
 AC_CHECK_FUNCS( [bzero drand48 ftruncate geteuid getgid \
 		 getuid getpwuid gettimeofday lstat memcpy memset \
 		 rand seteuid setegid snprintf setenv unsetenv tzset \
-		 sleep vsnprintf readlink gmtime_r localtime_r] )
+		 sleep vsnprintf readlink realpath gmtime_r localtime_r] )
 
 # check for timegm() support
 AC_CHECK_FUNC(timegm, AC_DEFINE(HAVE_TIMEGM,1,

include/cdio/util.h

@@ -1,7 +1,5 @@
 /*
-    $Id: util.h,v 1.12 2008/03/25 15:59:10 karl Exp $
+    Copyright (C) 2004, 2005, 2006, 2008, 2010 Rocky Bernstein <rocky@gnu.org>
-
-    Copyright (C) 2004, 2005, 2006, 2008 Rocky Bernstein <rocky@gnu.org>
     Copyright (C) 2000 Herbert Valerio Riedel <hvr@gnu.org>
 
     This program is free software: you can redistribute it and/or modify
@@ -28,6 +26,7 @@
    Warning: this will probably get removed/replaced by using glib.h
 */
 #include <stdlib.h>
+#include <cdio/types.h>
 
 #undef  MAX
 #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
@@ -99,7 +98,13 @@ _cdio_strsplit(const char str[], char delim);
 uint8_t cdio_to_bcd8(uint8_t n);
 uint8_t cdio_from_bcd8(uint8_t p);
 
-void cdio_follow_symlink (const char * src, char * dst);
+/*!  cdio_realpath() same as POSIX.1-2001 realpath if that's
+around. If not we do poor-man's simulation of that behavior.  */
+char *cdio_realpath (const char *psz_src, char *psz_dst);
+
+#ifdef WANT_FOLLOW_SYMLINK_COMPATIBILITY
+# define cdio_follow_symlink cdio_realpath
+#endif
   
 #ifdef __cplusplus
 }

lib/driver/Makefile.am

@@ -1,6 +1,4 @@
-#   $Id: Makefile.am,v 1.28 2008/10/20 01:25:15 rocky Exp $
+#   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
-#
-#   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
 #   Rocky Bernstein <rocky@gnu.org>
 #
 #   This program is free software: you can redistribute it and/or modify
@@ -67,7 +65,6 @@ libcdio_sources = \
 	device.c \
 	disc.c \
 	ds.c \
-        follow_symlink.c \
         FreeBSD/freebsd.c \
         FreeBSD/freebsd.h \
         FreeBSD/freebsd_cam.c \
@@ -93,6 +90,7 @@ libcdio_sources = \
 	os2.c \
 	osx.c \
 	read.c \
+        realpath.c \
 	sector.c \
 	solaris.c \
 	track.c \

lib/driver/_cdio_generic.c

@@ -230,10 +230,10 @@ cdio_add_device_list(char **device_list[], const char *drive,
     unsigned int j;
     char real_device_1[PATH_MAX];
     char real_device_2[PATH_MAX];
-    cdio_follow_symlink(drive, real_device_1);
+    cdio_realpath(drive, real_device_1);
     /* Check if drive is already in list. */
     for (j=0; j<*num_drives; j++) {
-      cdio_follow_symlink((*device_list)[j], real_device_2);
+      cdio_realpath((*device_list)[j], real_device_2);
       if (strcmp(real_device_1, real_device_2) == 0) break;
     }
 

lib/driver/gnu_linux.c

@@ -636,12 +636,18 @@ static int is_mounted (const char * device, char * target) {
   if(!fp) return 0;
 
   /* Get real device */
-  cdio_follow_symlink(device, real_device_1);
+  if (NULL == cdio_realpath(device, real_device_1)) {
+    cdio_warn("Problems resolving device %s: %s\n", device, strerror(errno));
+  }
+    
     
   /* Read entries */
 
   while ( fscanf(fp, "%s %s %*s %*s %*d %*d\n", file_device, file_target) != EOF ) {
-    cdio_follow_symlink(file_device, real_device_2);
+      if (NULL == cdio_realpath(file_device, real_device_2)) {
+          cdio_warn("Problems resolving device %s: %s\n", 
+                    file_device, strerror(errno));
+      }
     if(!strcmp(real_device_1, real_device_2)) {
       strcpy(target, file_target);
       fclose(fp);

lib/driver/realpath.c

@@ -18,15 +18,15 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 /*
-  Resolves symbolic links. 
+  POSIX realpath if that's around, and something like it if not.
 
   To compile as a standalone program:
-  gcc -Wall -g -I../.. -DHAVE_CONFIG_H -DSTANDALONE -o follow_symlink follow_symlink.c
+  gcc -Wall -g -I../.. -DHAVE_CONFIG_H -DSTANDALONE -o realpath realpath.c
 */
 /*
   Make sure we handle:
   - resolve relative links like  /dev/cdrom -> sr2
-  - abort on deep link nesting   /dev/cdrom -> /dev/cdrom
+  - abort on cyclic linking like /dev/cdrom -> /dev/cdrom
 */
 
 #ifdef HAVE_CONFIG_H
@@ -62,28 +62,30 @@
 #define PATH_MAX 4096
 #endif
 
-/*!
+#include <cdio/util.h>
-  Follow symlinks until we have the real device file
-  (idea taken from libunieject). 
-*/
 
-void cdio_follow_symlink (const char * src, char * dst) {
+/*!  cdio_realpath() same as POSIX.1-2001 realpath if that's
-#ifdef HAVE_READLINK
+around. If not we do poor-man's simulation of that behavior.  */
+char *cdio_realpath (const char *psz_src_path, char *psz_resolved_path) {
+
+#ifdef HAVE_REALPATH
+  psz_resolved_path = realpath(psz_src_path, psz_resolved_path);
+
+#elif defined(HAVE_READLINK)
   char tmp_src[PATH_MAX+1];
   char tmp_dst[PATH_MAX+1];
   char *p_adr;
-  int link_loop_limit = 100, i;
+  int i, len;
-  int len;
+  const int loop_limit = 100;
 
-  strcpy(tmp_src, src);
+  strcpy(tmp_src, psz_src_path);
 
   /* FIXME: 
      remove loop and change with stat before and after readlink 
      which looks direct symlink. Rely on errno to figure out other
      non-existent or looped symlinks. 
   */
-  for(i = 0; i < link_loop_limit; i++) {
+  for(i = 0; i < loop_limit; i++) {
-
     len = readlink(tmp_src, tmp_dst, PATH_MAX);
     if (-1 == len) {
 	/* Right now we expect a "not symlink" error. However after
@@ -93,7 +95,6 @@ void cdio_follow_symlink (const char * src, char * dst) {
 	break;
     } else {
 	tmp_dst[len] = '\0';
-	
 	if (tmp_dst[0] != '/') {
 	    /* Take care of relative link like  /dev/cdrom -> sr2 */
 	    p_adr = strrchr(tmp_src, '/');
@@ -108,11 +109,12 @@ void cdio_follow_symlink (const char * src, char * dst) {
 	tmp_src[PATH_MAX - 1] = 0; /* strncpy() does not always set a 0 */
     }
   }
-  strncpy(dst, tmp_src, PATH_MAX);
+  strncpy(psz_resolved_path, tmp_src, PATH_MAX);
-  
 #else
-  strncpy(dst, src, PATH_MAX);
+  strncpy(psz_resolved_path, psz_src_path, PATH_MAX);
 #endif
+
+  return psz_resolved_path;
   
 }
 
@@ -130,7 +132,7 @@ int main(int argc, char **argv)
   }
   for (i= 1; i < argc; i++) {
     dest[0] = 0;
-    cdio_follow_symlink (argv[i], dest);
+    cdio_realpath (argv[i], dest);
     printf("%s -> %s\n", argv[i], dest);
   }
   exit(0);

lib/iso9660/iso9660_fs.c

@@ -779,7 +779,7 @@ _iso9660_dir_to_statbuf (iso9660_dir_t *p_iso9660_dir, bool_3way_t b_xa,
 	  calloc(1, sizeof(iso9660_stat_t)+i_rr_fname+2);
         if (!p_stat_new)
           {
-          cdio_warn("Couldn't calloc(1, %d)", sizeof(iso9660_stat_t)+i_rr_fname+2);
+          cdio_warn("Couldn't calloc(1, %zd)", sizeof(iso9660_stat_t)+i_rr_fname+2);
           return NULL;
           }
 	memcpy(p_stat_new, p_stat, stat_len);

test/driver/Makefile.am

@@ -18,8 +18,8 @@ INCLUDES = -I$(top_srcdir) $(LIBCDIO_CFLAGS) $(LIBISO9660_CFLAGS)
 freebsd_LDADD    = $(LIBCDIO_LIBS) $(LTLIBICONV)
 freebsd_CFLAGS   = -DTEST_DIR=\"$(srcdir)\"
 
-follow_symlink_LDADD  = $(LIBCDIO_LIBS) $(LTLIBICONV)
+realpath_LDADD   = $(LIBCDIO_LIBS) $(LTLIBICONV)
-follow_symlink_CFLAGS = -DTEST_DIR=\"$(srcdir)\"
+realpath_CFLAGS  = -DTEST_DIR=\"$(srcdir)\"
 
 gnu_linux_LDADD  = $(LIBCDIO_LIBS) $(LTLIBICONV)
 gnu_linux_CFLAGS = -DTEST_DIR=\"$(srcdir)\"
@@ -36,7 +36,7 @@ solaris_CFLAGS   = -DTEST_DIR=\"$(srcdir)\"
 win32_LDADD      = $(LIBCDIO_LIBS) $(LTLIBICONV)
 win32_CFLAGS     = -DTEST_DIR=\"$(srcdir)\"
 
-check_PROGRAMS   = follow_symlink freebsd gnu_linux mmc osx solaris win32
+check_PROGRAMS   = freebsd gnu_linux mmc osx realpath solaris win32
 
 TESTS = $(check_PROGRAMS)
 

test/driver/realpath.c

@@ -121,9 +121,9 @@ main(int argc, const char *argv[])
 	if (0 == rc) {
 	    /* Just when you thought we'd forgotten, here is our first
 	       test! */
-	    cdio_follow_symlink(psz_symlink_file, psz_file_check);
+	    cdio_realpath(psz_symlink_file, psz_file_check);
 	    if (0 != strncmp(psz_file_check, psz_orig_file, PATH_MAX)) {
-		fprintf(stderr, "simple cdio_follow_symlink failed. %s vs %s\n",
+		fprintf(stderr, "simple cdio_realpath failed: %s vs %s\n",
 			psz_file_check, psz_orig_file);
 		exit(1);
 	    }
@@ -134,9 +134,9 @@ main(int argc, const char *argv[])
 	rc = check_rc(symlink(psz_symlink_file, psz_symlink_file),
 		      "symlink", psz_symlink_file);
 	if (0 == rc) {
-	    cdio_follow_symlink(psz_symlink_file, psz_file_check);
+	    cdio_realpath(psz_symlink_file, psz_file_check);
 	    if (0 != strncmp(psz_file_check, psz_symlink_file, PATH_MAX)) {
-		fprintf(stderr, "direct cdio_follow_symlink cycle test failed. %s vs %s\n",
+		fprintf(stderr, "direct cdio_realpath cycle test failed. %s vs %s\n",
 			psz_file_check, psz_orig_file);
 		exit(2);
 	    }