[svn-r19053] Purpose:

Add --no-dangling-links option to h5ls. 

Description:
Related to "Bug 1830 - Following an dangling external link in h5ls should set non-zero return code."
If --no-dangling-links option is specified and any dangling link is found, return exit code 1 (error).
Merged from hdf5 trunk r19051

Tested:
 jam, amani, heiwa

14 files changed, 355 insertions, 169 deletions

diff --git a/tools/h5ls/CMakeLists.txt b/tools/h5ls/CMakeLists.txt
index c2d9100..0a43c84 100644
--- a/tools/h5ls/CMakeLists.txt
+++ b/tools/h5ls/CMakeLists.txt
@@ -186,6 +186,17 @@ IF (BUILD_TESTING)
   ADD_H5_TEST (textlinksrc-6-old 0 -w80 -E textlinksrc.h5)
   ADD_H5_TEST (textlinksrc-7-old 0 -w80 -E textlinksrc.h5/ext_link1)
 
+  # tests for no-dangling-links 
+  # if this option is given on dangling link, h5ls should return exit code 1
+  # when used alone , expect to print out help and return exit code 1
+  ADD_H5_TEST (textlinksrc-nodangle-1 1 -w80 --no-dangling-links textlinksrc.h5)
+  # external dangling link - expected exit code 1
+  ADD_H5_TEST (textlinksrc-nodangle-2 1 -w80 --follow-symlinks --no-dangling-links textlinksrc.h5)
+  # soft dangling link - expected exit code 1
+  ADD_H5_TEST (tsoftlinks-nodangle-1 1 -w80 --follow-symlinks --no-dangling-links tsoftlinks.h5)
+  # when used file with no dangling links - expected exit code 0
+  ADD_H5_TEST (thlinks-nodangle-1 0 -w80 --follow-symlinks --no-dangling-links thlink.h5)
+
   # tests for hard links
   ADD_H5_TEST (thlink-1 0 -w80 thlink.h5)
 
diff --git a/tools/h5ls/h5ls.c b/tools/h5ls/h5ls.c
index 789e02a..fb08ddb 100644
--- a/tools/h5ls/h5ls.c
+++ b/tools/h5ls/h5ls.c
@@ -43,6 +43,7 @@ typedef struct symlink_trav_t {
         char *file;
         char *path;
     } *objs;
+    hbool_t dangle_link;
 } symlink_trav_t;
 
 /* Struct to pass through to visitors */
@@ -66,6 +67,7 @@ static hbool_t  string_g = FALSE;         /* print 1-byte numbers as ASCII? */
 static hbool_t  fullname_g = FALSE;       /* print full path names */
 static hbool_t  recursive_g = FALSE;      /* recursive descent listing */
 static hbool_t  follow_symlink_g = FALSE; /* follow symbolic links */
+static hbool_t  no_dangling_link_g = FALSE; /* treat dangling link is error */
 static hbool_t  follow_elink_g = FALSE;   /* follow external links */
 static hbool_t  grp_literal_g = FALSE;    /* list group, not contents */
 static hbool_t  hexdump_g = FALSE;        /* show data as raw hexadecimal */
@@ -114,28 +116,38 @@ usage (void)
     fprintf(stderr, "\
 usage: %s [OPTIONS] [OBJECTS...]\n\
   OPTIONS\n\
-   -h, -?, --help     Print a usage message and exit\n\
-   -a, --address      Print addresses for raw data\n\
-   -d, --data         Print the values of datasets\n\
-   -e, --errors       Show all HDF5 error reporting\n\
-   --follow-symlinks  Follow symbolic links (soft links and external links)\n\
-                      to display target object information.\n\
-                      Without this option, h5ls identifies a symbolic link\n\
-                      as a soft link or external link and prints the value\n\
-                      assigned to the symbolic link; it does not provide any\n\
-                      information regarding the target object or determine\n\
-                      whether the link is a dangling link.\n\
-   -f, --full         Print full path names instead of base names\n\
-   -g, --group        Show information about a group, not its contents\n\
-   -l, --label        Label members of compound datasets\n\
-   -r, --recursive    List all groups recursively, avoiding cycles\n\
-   -s, --string       Print 1-byte integer datasets as ASCII\n\
-   -S, --simple       Use a machine-readable output format\n\
-   -wN, --width=N     Set the number of columns of output\n\
-   -v, --verbose      Generate more verbose output\n\
-   -V, --version      Print version number and exit\n\
-   --vfd=DRIVER       Use the specified virtual file driver\n\
-   -x, --hexdump      Show raw data in hexadecimal format\n\
+   -h, -?, --help  Print a usage message and exit\n\
+   -a, --address   Print addresses for raw data\n\
+   -d, --data      Print the values of datasets\n\
+   -e, --errors    Show all HDF5 error reporting\n\
+   --follow-symlinks\n\
+                   Follow symbolic links (soft links and external links)\n\
+                   to display target object information.\n\
+                   Without this option, h5ls identifies a symbolic link\n\
+                   as a soft link or external link and prints the value\n\
+                   assigned to the symbolic link; it does not provide any\n\
+                   information regarding the target object or determine\n\
+                   whether the link is a dangling link.\n\
+   --no-dangling-links\n\
+                   Must be used with --follow-symlinks option;\n\
+                   otherwise, h5ls shows error message and returns an exit\n\
+                   code of 1. \n\
+                   Check for any symbolic links (soft links or external links)\n\
+                   that do not resolve to an existing object (dataset, group,\n\
+                   or named datatype).\n\
+                   If any dangling link is found, this situation is treated\n\
+                   as an error and h5ls returns an exit code of 1.\n\
+   -f, --full      Print full path names instead of base names\n\
+   -g, --group     Show information about a group, not its contents\n\
+   -l, --label     Label members of compound datasets\n\
+   -r, --recursive List all groups recursively, avoiding cycles\n\
+   -s, --string    Print 1-byte integer datasets as ASCII\n\
+   -S, --simple    Use a machine-readable output format\n\
+   -wN, --width=N  Set the number of columns of output\n\
+   -v, --verbose   Generate more verbose output\n\
+   -V, --version   Print version number and exit\n\
+   --vfd=DRIVER    Use the specified virtual file driver\n\
+   -x, --hexdump   Show raw data in hexadecimal format\n\
 \n\
   OBJECTS\n\
     Each object consists of an HDF5 file name optionally followed by a\n\
@@ -170,8 +182,6 @@ usage: %s [OPTIONS] [OBJECTS...]\n\
  *              Thursday, November  5, 1998
  *
  * Modifications:
- *   Add _H5LS_CONVERT_SPECIAL_CHAR_ #ifdef section and make it not to
- *   convert special chars to visible chars. (Jonathan Kim  06/24/2010)
  *
  *-------------------------------------------------------------------------
  */
@@ -180,27 +190,6 @@ display_string(FILE *stream, const char *s, hbool_t escape_spaces)
 {
     int  nprint=0;
 
-#ifdef _H5LS_CONVERT_SPECIAL_CHAR_
-    /*-------------------------------------------------------------------
-     * _H5LS_CONVERT_SPECIAL_CHAR_ is not defined, so this code section 
-     * will not be compiled. 
-     * This code section is due to be removed after verifying no problem 
-     * at customer sites. (However we may keep it just for the future
-     * reference as it survived over ten years)
-     *
-     * Reason for Obsolete: 
-     *  This portion of code converts special characters or '\' to string, 
-     *  so when those characters are in object or attribute name, h5ls display
-     *  as visible characters.     
-     *  However if a user come up with object or attribute name with special 
-     *  character in programming, this code takes away control over '\' 
-     *  (escape character) from the user and causes confusion for the output, 
-     *  also it’s not possible to handle all the cases in this way. 
-     *  This also causes discrepancy from how the string data saved in 
-     *  HDF5 file.
-     *  Also other HDF tools don’t convert characters like this, so this 
-     *  causes inconsistent output among tools.
-     *-------------------------------------------------------------/
     for (/*void*/; s && *s; s++) {
         switch (*s) {
             case '"':
@@ -253,17 +242,6 @@ display_string(FILE *stream, const char *s, hbool_t escape_spaces)
                 break;
         }
     }
-#else
-    if (stream)
-    {
-        nprint = fprintf(stream,s);
-    }
-    else
-    {
-        nprint = strlen(s);
-    }
-#endif /* _H5LS_CONVERT_SPECIAL_CHAR_ */
-
     return nprint;
 }
 
@@ -1999,18 +1977,31 @@ list_lnk(const char *name, const H5L_info_t *linfo, void *_iter)
 {
     char *buf=NULL;
     iter_t *iter = (iter_t*)_iter;
+    int ret;
+    h5tool_link_info_t lnk_info;
+
+    /* init linkinfo struct */
+    memset(&lnk_info, 0, sizeof(h5tool_link_info_t));
+
+    /* if verbose, make H5tools_get_link_info() display more */
+    if (verbose_g)
+        lnk_info.opt.msg_mode=1;
 
     /* Print the link's name, either full name or base name */
     display_obj_name(stdout, iter, name, "");
 
     switch(linfo->type) {
         case H5L_TYPE_SOFT:
-            if((buf = (char*)HDmalloc(linfo->u.val_size)) == NULL)
+            ret = H5tools_get_link_info(iter->fid, name, &lnk_info);
+            /* lnk_info.trg_path is malloced in H5tools_get_link_info()
+             * so it will be freed via buf later */
+            buf = lnk_info.trg_path;
+            /* error */
+            if (ret < 0)
                 goto done;
-
-            if(H5Lget_val(iter->fid, name, buf, linfo->u.val_size, H5P_DEFAULT) < 0) {
-                goto done;
-            } /* end if */
+            /* no dangling link option given and detect dangling link */
+            else if (no_dangling_link_g && ret == 0)
+                iter->symlink_list->dangle_link = TRUE;
 
             HDfputs("Soft Link {", stdout);
             HDfputs(buf, stdout);
@@ -2058,10 +2049,16 @@ list_lnk(const char *name, const H5L_info_t *linfo, void *_iter)
             const char *filename;
             const char *path;
 
-            if((buf = (char*)HDmalloc(linfo->u.val_size)) == NULL)
-                goto done;
-            if(H5Lget_val(iter->fid, name, buf, linfo->u.val_size, H5P_DEFAULT) < 0) 
+            ret = H5tools_get_link_info(iter->fid, name, &lnk_info);
+            /* lnk_info.trg_path is malloced in H5tools_get_link_info()
+             * so it will be freed via buf later */
+            buf = lnk_info.trg_path;
+            /* error */
+            if (ret < 0)
                 goto done;
+            /* no dangling link option given and detect dangling link */
+            else if (no_dangling_link_g && ret == 0)
+                iter->symlink_list->dangle_link = TRUE;
 
             if(H5Lunpack_elink_val(buf, linfo->u.val_size, NULL, &filename, &path) < 0) 
                 goto done;
@@ -2134,9 +2131,9 @@ done:
  *
  * Purpose: Begins iteration on an object
  *
- * Return: Success: EXIT_SUCCESS(0)
- *
- * Failure: EXIT_FAILURE(1)
+ * Return: 
+ *  Success: 0
+ *  Failure: -1
  *
  * Programmer: Neil Fortner
  *              Wednesday, August 21, 2008
@@ -2272,6 +2269,42 @@ get_width(void)
     return width;
 }
 
+/*-------------------------------------------------------------------------
+ * Function: is_valid_args
+ *
+ * Purpose: check if command line arguments are valid
+ *
+ * Return: 
+ *  Success: TRUE (1)
+ *  Failure: FALSE (0)
+ *
+ * Programmer:
+ *  Jonathan Kim  (06/15/2010)
+ *
+ *-------------------------------------------------------------------------*/
+static hbool_t 
+is_valid_args(void)
+{
+    herr_t ret = TRUE;
+
+    if(recursive_g && grp_literal_g) 
+    {
+        fprintf(stderr, "Error: 'recursive' option not compatible with 'group info' option!\n\n");
+        ret = FALSE;
+        goto out;
+    }
+
+    if(no_dangling_link_g && !follow_symlink_g) 
+    {
+        fprintf(stderr, "Error: --no-dangling-links must be used along with --follow-symlinks option!\n\n");
+        ret = FALSE;
+        goto out;
+    }
+
+out:
+    return ret;
+}
+
 
 /*-------------------------------------------------------------------------
  * Function: leave
@@ -2323,7 +2356,7 @@ main(int argc, const char *argv[])
     static char root_name[] = "/";
     char        drivername[50];
     const char *preferred_driver = NULL;
-    int err_openfile = 0;
+    int err_exit = 0;
 
     h5tools_setprogname(PROGRAMNAME);
     h5tools_setstatus(EXIT_SUCCESS);
@@ -2356,6 +2389,8 @@ main(int argc, const char *argv[])
             show_errors_g = TRUE;
         } else if(!HDstrcmp(argv[argno], "--follow-symlinks")) {
             follow_symlink_g = TRUE;
+        } else if(!HDstrcmp(argv[argno], "--no-dangling-links")) {
+            no_dangling_link_g = TRUE;
         } else if(!HDstrcmp(argv[argno], "--external")) {
             follow_elink_g = TRUE;
         } else if(!HDstrcmp(argv[argno], "--full")) {
@@ -2499,11 +2534,11 @@ main(int argc, const char *argv[])
     } /* end if */
 
     /* Check for conflicting arguments */
-    if(recursive_g && grp_literal_g) {
-        fprintf(stderr, "Error: 'recursive' option not compatible with 'group info' option!\n\n");
+    if (!is_valid_args())
+    {
         usage();
         leave(EXIT_FAILURE);
-    } /* end if */
+    }
 
     /* Turn off HDF5's automatic error printing unless you're debugging h5ls */
     if(!show_errors_g)
@@ -2555,7 +2590,7 @@ main(int argc, const char *argv[])
         if(file < 0) {
             fprintf(stderr, "%s: unable to open file\n", argv[argno-1]);
             HDfree(fname);
-            err_openfile = 1;
+            err_exit = 1;
             continue;
         } /* end if */
         if(oname) {
@@ -2590,6 +2625,7 @@ main(int argc, const char *argv[])
         iter.gid = -1;
         iter.symlink_target = FALSE;
         iter.symlink_list = &symlink_list;
+        iter.symlink_list->dangle_link = FALSE;
 
         /* Initialize list of visited symbolic links */
         symlink_list.nused = symlink_list.nalloc = 0;
@@ -2630,9 +2666,13 @@ main(int argc, const char *argv[])
             HDfree(symlink_list.objs[u].path);
         }
         HDfree(symlink_list.objs);
+        
+        /* if no-dangling-links option specified and dangling link found */
+        if (no_dangling_link_g && iter.symlink_list->dangle_link)
+            err_exit = 1;
     } /* end while */
 
-    if (err_openfile)
+    if (err_exit)
         leave(EXIT_FAILURE);
     else
         leave(EXIT_SUCCESS);
diff --git a/tools/h5ls/testh5ls.sh.in b/tools/h5ls/testh5ls.sh.in
index 7f07898..642241f 100644
--- a/tools/h5ls/testh5ls.sh.in
+++ b/tools/h5ls/testh5ls.sh.in
@@ -167,6 +167,18 @@ TOOLTEST textlinksrc-3-old.ls 0 -w80 -Er textlinksrc.h5/ext_link1
 TOOLTEST textlinksrc-6-old.ls 0 -w80 -E textlinksrc.h5
 TOOLTEST textlinksrc-7-old.ls 0 -w80 -E textlinksrc.h5/ext_link1
 
+# tests for no-dangling-links 
+# if this option is given on dangling link, h5ls should return exit code 1
+# when used alone , expect to print out help and return exit code 1
+TOOLTEST textlinksrc-nodangle-1.ls 1 -w80 --no-dangling-links textlinksrc.h5
+# external dangling link - expected exit code 1
+TOOLTEST textlinksrc-nodangle-2.ls 1 -w80 --follow-symlinks --no-dangling-links textlinksrc.h5
+# soft dangling link - expected exit code 1
+TOOLTEST tsoftlinks-nodangle-1.ls 1 -w80 --follow-symlinks --no-dangling-links tsoftlinks.h5
+# when used file with no dangling links - expected exit code 0
+TOOLTEST thlinks-nodangle-1.ls 0 -w80 --follow-symlinks --no-dangling-links thlink.h5
+
+
 # tests for hard links
 TOOLTEST thlink-1.ls 0 -w80 thlink.h5
 
diff --git a/tools/lib/h5tools_utils.c b/tools/lib/h5tools_utils.c
index 0913501..b4c4cf5 100644
--- a/tools/lib/h5tools_utils.c
+++ b/tools/lib/h5tools_utils.c
@@ -638,7 +638,6 @@ tmpfile(void)
  * Patameters:
  *  - [IN]  fileid : link file id
  *  - [IN]  linkpath : link path
- *  - [OUT] h5li : link's info (H5L_info_t)
  *  - [OUT] link_info: returning target object info (h5tool_link_info_t)
  *
  * Return: 
@@ -656,7 +655,7 @@ tmpfile(void)
  *-------------------------------------------------------------------------*/
 int H5tools_get_link_info(hid_t file_id, const char * linkpath, h5tool_link_info_t *link_info)
 {
-    int Ret = -1; /* init to fail */
+    int ret = -1; /* init to fail */
     htri_t l_ret;
     H5O_info_t trg_oinfo;
     hid_t fapl;
@@ -684,7 +683,7 @@ int H5tools_get_link_info(hid_t file_id, const char * linkpath, h5tool_link_info
     /* given path is hard link (object) */
     if (link_info->linfo.type == H5L_TYPE_HARD)
     {
-        Ret = 2;
+        ret = 2;
         goto out;
     }
 
@@ -721,7 +720,7 @@ int H5tools_get_link_info(hid_t file_id, const char * linkpath, h5tool_link_info
     /* detect dangling link */
     if(l_ret == FALSE) 
     {
-            Ret = 0;
+            ret = 0;
             goto out;
     }
     /* function failed */
@@ -750,7 +749,7 @@ int H5tools_get_link_info(hid_t file_id, const char * linkpath, h5tool_link_info
     link_info->trg_type = trg_oinfo.type;
 
     /* succeed */
-    Ret = 1;
+    ret = 1;
 out:
     if (link_info->linfo.type == H5L_TYPE_EXTERNAL)
     {
@@ -758,7 +757,7 @@ out:
         H5Pclose(lapl);
     }
 
-    return Ret;
+    return ret;
 }
 
 /*-------------------------------------------------------------------------
diff --git a/tools/testfiles/help-1.ls b/tools/testfiles/help-1.ls
index 1b5de0c..6a2904e 100644
--- a/tools/testfiles/help-1.ls
+++ b/tools/testfiles/help-1.ls
@@ -3,28 +3,38 @@
 #############################
 usage: h5ls [OPTIONS] [OBJECTS...]
   OPTIONS
-   -h, -?, --help     Print a usage message and exit
-   -a, --address      Print addresses for raw data
-   -d, --data         Print the values of datasets
-   -e, --errors       Show all HDF5 error reporting
-   --follow-symlinks  Follow symbolic links (soft links and external links)
-                      to display target object information.
-                      Without this option, h5ls identifies a symbolic link
-                      as a soft link or external link and prints the value
-                      assigned to the symbolic link; it does not provide any
-                      information regarding the target object or determine
-                      whether the link is a dangling link.
-   -f, --full         Print full path names instead of base names
-   -g, --group        Show information about a group, not its contents
-   -l, --label        Label members of compound datasets
-   -r, --recursive    List all groups recursively, avoiding cycles
-   -s, --string       Print 1-byte integer datasets as ASCII
-   -S, --simple       Use a machine-readable output format
-   -wN, --width=N     Set the number of columns of output
-   -v, --verbose      Generate more verbose output
-   -V, --version      Print version number and exit
-   --vfd=DRIVER       Use the specified virtual file driver
-   -x, --hexdump      Show raw data in hexadecimal format
+   -h, -?, --help  Print a usage message and exit
+   -a, --address   Print addresses for raw data
+   -d, --data      Print the values of datasets
+   -e, --errors    Show all HDF5 error reporting
+   --follow-symlinks
+                   Follow symbolic links (soft links and external links)
+                   to display target object information.
+                   Without this option, h5ls identifies a symbolic link
+                   as a soft link or external link and prints the value
+                   assigned to the symbolic link; it does not provide any
+                   information regarding the target object or determine
+                   whether the link is a dangling link.
+   --no-dangling-links
+                   Must be used with --follow-symlinks option;
+                   otherwise, h5ls shows error message and returns an exit
+                   code of 1. 
+                   Check for any symbolic links (soft links or external links)
+                   that do not resolve to an existing object (dataset, group,
+                   or named datatype).
+                   If any dangling link is found, this situation is treated
+                   as an error and h5ls returns an exit code of 1.
+   -f, --full      Print full path names instead of base names
+   -g, --group     Show information about a group, not its contents
+   -l, --label     Label members of compound datasets
+   -r, --recursive List all groups recursively, avoiding cycles
+   -s, --string    Print 1-byte integer datasets as ASCII
+   -S, --simple    Use a machine-readable output format
+   -wN, --width=N  Set the number of columns of output
+   -v, --verbose   Generate more verbose output
+   -V, --version   Print version number and exit
+   --vfd=DRIVER    Use the specified virtual file driver
+   -x, --hexdump   Show raw data in hexadecimal format
 
   OBJECTS
     Each object consists of an HDF5 file name optionally followed by a
diff --git a/tools/testfiles/help-2.ls b/tools/testfiles/help-2.ls
index 6f7e75d..92163d1 100644
--- a/tools/testfiles/help-2.ls
+++ b/tools/testfiles/help-2.ls
@@ -3,28 +3,38 @@
 #############################
 usage: h5ls [OPTIONS] [OBJECTS...]
   OPTIONS
-   -h, -?, --help     Print a usage message and exit
-   -a, --address      Print addresses for raw data
-   -d, --data         Print the values of datasets
-   -e, --errors       Show all HDF5 error reporting
-   --follow-symlinks  Follow symbolic links (soft links and external links)
-                      to display target object information.
-                      Without this option, h5ls identifies a symbolic link
-                      as a soft link or external link and prints the value
-                      assigned to the symbolic link; it does not provide any
-                      information regarding the target object or determine
-                      whether the link is a dangling link.
-   -f, --full         Print full path names instead of base names
-   -g, --group        Show information about a group, not its contents
-   -l, --label        Label members of compound datasets
-   -r, --recursive    List all groups recursively, avoiding cycles
-   -s, --string       Print 1-byte integer datasets as ASCII
-   -S, --simple       Use a machine-readable output format
-   -wN, --width=N     Set the number of columns of output
-   -v, --verbose      Generate more verbose output
-   -V, --version      Print version number and exit
-   --vfd=DRIVER       Use the specified virtual file driver
-   -x, --hexdump      Show raw data in hexadecimal format
+   -h, -?, --help  Print a usage message and exit
+   -a, --address   Print addresses for raw data
+   -d, --data      Print the values of datasets
+   -e, --errors    Show all HDF5 error reporting
+   --follow-symlinks
+                   Follow symbolic links (soft links and external links)
+                   to display target object information.
+                   Without this option, h5ls identifies a symbolic link
+                   as a soft link or external link and prints the value
+                   assigned to the symbolic link; it does not provide any
+                   information regarding the target object or determine
+                   whether the link is a dangling link.
+   --no-dangling-links
+                   Must be used with --follow-symlinks option;
+                   otherwise, h5ls shows error message and returns an exit
+                   code of 1. 
+                   Check for any symbolic links (soft links or external links)
+                   that do not resolve to an existing object (dataset, group,
+                   or named datatype).
+                   If any dangling link is found, this situation is treated
+                   as an error and h5ls returns an exit code of 1.
+   -f, --full      Print full path names instead of base names
+   -g, --group     Show information about a group, not its contents
+   -l, --label     Label members of compound datasets
+   -r, --recursive List all groups recursively, avoiding cycles
+   -s, --string    Print 1-byte integer datasets as ASCII
+   -S, --simple    Use a machine-readable output format
+   -wN, --width=N  Set the number of columns of output
+   -v, --verbose   Generate more verbose output
+   -V, --version   Print version number and exit
+   --vfd=DRIVER    Use the specified virtual file driver
+   -x, --hexdump   Show raw data in hexadecimal format
 
   OBJECTS
     Each object consists of an HDF5 file name optionally followed by a
diff --git a/tools/testfiles/help-3.ls b/tools/testfiles/help-3.ls
index 939c8eb..7199815 100644
--- a/tools/testfiles/help-3.ls
+++ b/tools/testfiles/help-3.ls
@@ -3,28 +3,38 @@
 #############################
 usage: h5ls [OPTIONS] [OBJECTS...]
   OPTIONS
-   -h, -?, --help     Print a usage message and exit
-   -a, --address      Print addresses for raw data
-   -d, --data         Print the values of datasets
-   -e, --errors       Show all HDF5 error reporting
-   --follow-symlinks  Follow symbolic links (soft links and external links)
-                      to display target object information.
-                      Without this option, h5ls identifies a symbolic link
-                      as a soft link or external link and prints the value
-                      assigned to the symbolic link; it does not provide any
-                      information regarding the target object or determine
-                      whether the link is a dangling link.
-   -f, --full         Print full path names instead of base names
-   -g, --group        Show information about a group, not its contents
-   -l, --label        Label members of compound datasets
-   -r, --recursive    List all groups recursively, avoiding cycles
-   -s, --string       Print 1-byte integer datasets as ASCII
-   -S, --simple       Use a machine-readable output format
-   -wN, --width=N     Set the number of columns of output
-   -v, --verbose      Generate more verbose output
-   -V, --version      Print version number and exit
-   --vfd=DRIVER       Use the specified virtual file driver
-   -x, --hexdump      Show raw data in hexadecimal format
+   -h, -?, --help  Print a usage message and exit
+   -a, --address   Print addresses for raw data
+   -d, --data      Print the values of datasets
+   -e, --errors    Show all HDF5 error reporting
+   --follow-symlinks
+                   Follow symbolic links (soft links and external links)
+                   to display target object information.
+                   Without this option, h5ls identifies a symbolic link
+                   as a soft link or external link and prints the value
+                   assigned to the symbolic link; it does not provide any
+                   information regarding the target object or determine
+                   whether the link is a dangling link.
+   --no-dangling-links
+                   Must be used with --follow-symlinks option;
+                   otherwise, h5ls shows error message and returns an exit
+                   code of 1. 
+                   Check for any symbolic links (soft links or external links)
+                   that do not resolve to an existing object (dataset, group,
+                   or named datatype).
+                   If any dangling link is found, this situation is treated
+                   as an error and h5ls returns an exit code of 1.
+   -f, --full      Print full path names instead of base names
+   -g, --group     Show information about a group, not its contents
+   -l, --label     Label members of compound datasets
+   -r, --recursive List all groups recursively, avoiding cycles
+   -s, --string    Print 1-byte integer datasets as ASCII
+   -S, --simple    Use a machine-readable output format
+   -wN, --width=N  Set the number of columns of output
+   -v, --verbose   Generate more verbose output
+   -V, --version   Print version number and exit
+   --vfd=DRIVER    Use the specified virtual file driver
+   -x, --hexdump   Show raw data in hexadecimal format
 
   OBJECTS
     Each object consists of an HDF5 file name optionally followed by a
diff --git a/tools/testfiles/textlinksrc-2-old.ls b/tools/testfiles/textlinksrc-2-old.ls
index acdc3d2..403a1d2 100644
--- a/tools/testfiles/textlinksrc-2-old.ls
+++ b/tools/testfiles/textlinksrc-2-old.ls
@@ -3,6 +3,6 @@
 #############################
 Opened "textlinksrc.h5" with sec2 driver.
 ext_link5                External Link {textlinktar.h5//empty_group} {Group
-    Location:  3:1832
+    Location:  5:1832
     Links:     1
 }
diff --git a/tools/testfiles/textlinksrc-2.ls b/tools/testfiles/textlinksrc-2.ls
index ea99be8..1e92f59 100644
--- a/tools/testfiles/textlinksrc-2.ls
+++ b/tools/testfiles/textlinksrc-2.ls
@@ -3,6 +3,6 @@
 #############################
 Opened "textlinksrc.h5" with sec2 driver.
 ext_link5                External Link {textlinktar.h5//empty_group} {Group
-    Location:  3:1832
+    Location:  5:1832
     Links:     1
 }
diff --git a/tools/testfiles/textlinksrc-nodangle-1.ls b/tools/testfiles/textlinksrc-nodangle-1.ls
new file mode 100644
index 0000000..8a6144b
--- /dev/null
+++ b/tools/testfiles/textlinksrc-nodangle-1.ls
@@ -0,0 +1,56 @@
+#############################
+ output for 'h5ls -w80 --no-dangling-links textlinksrc.h5'
+#############################
+Error: --no-dangling-links must be used along with --follow-symlinks option!
+
+usage: h5ls [OPTIONS] [OBJECTS...]
+  OPTIONS
+   -h, -?, --help  Print a usage message and exit
+   -a, --address   Print addresses for raw data
+   -d, --data      Print the values of datasets
+   -e, --errors    Show all HDF5 error reporting
+   --follow-symlinks
+                   Follow symbolic links (soft links and external links)
+                   to display target object information.
+                   Without this option, h5ls identifies a symbolic link
+                   as a soft link or external link and prints the value
+                   assigned to the symbolic link; it does not provide any
+                   information regarding the target object or determine
+                   whether the link is a dangling link.
+   --no-dangling-links
+                   Must be used with --follow-symlinks option;
+                   otherwise, h5ls shows error message and returns an exit
+                   code of 1. 
+                   Check for any symbolic links (soft links or external links)
+                   that do not resolve to an existing object (dataset, group,
+                   or named datatype).
+                   If any dangling link is found, this situation is treated
+                   as an error and h5ls returns an exit code of 1.
+   -f, --full      Print full path names instead of base names
+   -g, --group     Show information about a group, not its contents
+   -l, --label     Label members of compound datasets
+   -r, --recursive List all groups recursively, avoiding cycles
+   -s, --string    Print 1-byte integer datasets as ASCII
+   -S, --simple    Use a machine-readable output format
+   -wN, --width=N  Set the number of columns of output
+   -v, --verbose   Generate more verbose output
+   -V, --version   Print version number and exit
+   --vfd=DRIVER    Use the specified virtual file driver
+   -x, --hexdump   Show raw data in hexadecimal format
+
+  OBJECTS
+    Each object consists of an HDF5 file name optionally followed by a
+    slash and an object name within the file (if no object is specified
+    within the file then the contents of the root group are displayed).
+    The file name may include a printf(3C) integer format such as
+    "%05d" to open a file family.
+
+  Deprecated Options
+    The following options have been deprecated in HDF5. While they remain
+    available, they have been superseded as indicated and may be removed
+    from HDF5 in the future. Use the indicated replacement option in all
+    new work; where possible, existing scripts, et cetera, should also be
+    updated to use the replacement option.
+
+   -E or --external   Follow external links.
+                      Replaced by --follow-symlinks.
diff --git a/tools/testfiles/textlinksrc-nodangle-2.ls b/tools/testfiles/textlinksrc-nodangle-2.ls
new file mode 100644
index 0000000..4713849
--- /dev/null
+++ b/tools/testfiles/textlinksrc-nodangle-2.ls
@@ -0,0 +1,8 @@
+#############################
+ output for 'h5ls -w80 --follow-symlinks --no-dangling-links textlinksrc.h5'
+#############################
+ext_link1                External Link {textlinktar.h5//group} {Group}
+ext_link2                External Link {textlinktar.h5//dset} {Dataset {6}}
+ext_link3                External Link {textlinktar.h5//type} {Type}
+ext_link4                External Link {textlinktar.h5//group/elink_t2} {**NOT FOUND**}
+ext_link5                External Link {textlinktar.h5//empty_group} {Group}
diff --git a/tools/testfiles/tgroup-1.ls b/tools/testfiles/tgroup-1.ls
index 8d38e0f..03a70fd 100644
--- a/tools/testfiles/tgroup-1.ls
+++ b/tools/testfiles/tgroup-1.ls
@@ -5,28 +5,38 @@ Error: 'recursive' option not compatible with 'group info' option!
 
 usage: h5ls [OPTIONS] [OBJECTS...]
   OPTIONS
-   -h, -?, --help     Print a usage message and exit
-   -a, --address      Print addresses for raw data
-   -d, --data         Print the values of datasets
-   -e, --errors       Show all HDF5 error reporting
-   --follow-symlinks  Follow symbolic links (soft links and external links)
-                      to display target object information.
-                      Without this option, h5ls identifies a symbolic link
-                      as a soft link or external link and prints the value
-                      assigned to the symbolic link; it does not provide any
-                      information regarding the target object or determine
-                      whether the link is a dangling link.
-   -f, --full         Print full path names instead of base names
-   -g, --group        Show information about a group, not its contents
-   -l, --label        Label members of compound datasets
-   -r, --recursive    List all groups recursively, avoiding cycles
-   -s, --string       Print 1-byte integer datasets as ASCII
-   -S, --simple       Use a machine-readable output format
-   -wN, --width=N     Set the number of columns of output
-   -v, --verbose      Generate more verbose output
-   -V, --version      Print version number and exit
-   --vfd=DRIVER       Use the specified virtual file driver
-   -x, --hexdump      Show raw data in hexadecimal format
+   -h, -?, --help  Print a usage message and exit
+   -a, --address   Print addresses for raw data
+   -d, --data      Print the values of datasets
+   -e, --errors    Show all HDF5 error reporting
+   --follow-symlinks
+                   Follow symbolic links (soft links and external links)
+                   to display target object information.
+                   Without this option, h5ls identifies a symbolic link
+                   as a soft link or external link and prints the value
+                   assigned to the symbolic link; it does not provide any
+                   information regarding the target object or determine
+                   whether the link is a dangling link.
+   --no-dangling-links
+                   Must be used with --follow-symlinks option;
+                   otherwise, h5ls shows error message and returns an exit
+                   code of 1. 
+                   Check for any symbolic links (soft links or external links)
+                   that do not resolve to an existing object (dataset, group,
+                   or named datatype).
+                   If any dangling link is found, this situation is treated
+                   as an error and h5ls returns an exit code of 1.
+   -f, --full      Print full path names instead of base names
+   -g, --group     Show information about a group, not its contents
+   -l, --label     Label members of compound datasets
+   -r, --recursive List all groups recursively, avoiding cycles
+   -s, --string    Print 1-byte integer datasets as ASCII
+   -S, --simple    Use a machine-readable output format
+   -wN, --width=N  Set the number of columns of output
+   -v, --verbose   Generate more verbose output
+   -V, --version   Print version number and exit
+   --vfd=DRIVER    Use the specified virtual file driver
+   -x, --hexdump   Show raw data in hexadecimal format
 
   OBJECTS
     Each object consists of an HDF5 file name optionally followed by a
diff --git a/tools/testfiles/thlinks-nodangle-1.ls b/tools/testfiles/thlinks-nodangle-1.ls
new file mode 100644
index 0000000..37ba6b0
--- /dev/null
+++ b/tools/testfiles/thlinks-nodangle-1.ls
@@ -0,0 +1,7 @@
+#############################
+ output for 'h5ls -w80 --follow-symlinks --no-dangling-links thlink.h5'
+#############################
+dset1                    Dataset {5}
+g1                       Group
+g2                       Group
+g3                       Group, same as /
diff --git a/tools/testfiles/tsoftlinks-nodangle-1.ls b/tools/testfiles/tsoftlinks-nodangle-1.ls
new file mode 100644
index 0000000..6d639b7
--- /dev/null
+++ b/tools/testfiles/tsoftlinks-nodangle-1.ls
@@ -0,0 +1,13 @@
+#############################
+ output for 'h5ls -w80 --follow-symlinks --no-dangling-links tsoftlinks.h5'
+#############################
+dset1                    Dataset {4, 2}
+dset2                    Dataset {4, 2}
+dtype                    Type
+group1                   Group
+group_empty              Group
+soft_dangle              Soft Link {not_yet} {**NOT FOUND**}
+soft_dset1               Soft Link {/dset1} {Dataset {4, 2}}
+soft_dtype               Soft Link {/dtype} {Type}
+soft_empty_grp           Soft Link {/group_empty} {Group}
+soft_group1              Soft Link {/group1} {Group}