HDFFV-9995 Clarify help text

11 files changed, 144 insertions, 111 deletions

diff --git a/tools/src/h5diff/h5diff_common.c b/tools/src/h5diff/h5diff_common.c
index 5437803..0537b9f 100644
--- a/tools/src/h5diff/h5diff_common.c
+++ b/tools/src/h5diff/h5diff_common.c
@@ -56,7 +56,7 @@ static struct long_options l_opts[] = {
 static void check_options(diff_opt_t* options)
 {
     /*--------------------------------------------------------------
-     * check for mutually exclusive options 
+     * check for mutually exclusive options
      *--------------------------------------------------------------*/
 
     /* check between -d , -p, --use-system-epsilon.
@@ -127,13 +127,13 @@ void parse_command_line(int argc,
             h5diff_exit(EXIT_SUCCESS);
         case 'v':
             options->m_verbose = 1;
-            /* This for loop is for handling style like 
+            /* This for loop is for handling style like
              * -v, -v1, --verbose, --verbose=1.
              */
             for (i = 1; i < argc; i++)
-            {                
-                /* 
-                 * short opt 
+            {
+                /*
+                 * short opt
                  */
                 if (!strcmp (argv[i], "-v"))  /* no arg */
             {
@@ -145,10 +145,10 @@ void parse_command_line(int argc,
             {
                     options->m_verbose_level = atoi(&argv[i][2]);
                     break;
-            }    
+            }
 
-                /* 
-                 * long opt 
+                /*
+                 * long opt
                  */
                 if (!strcmp (argv[i], "--verbose"))  /* no arg */
             {
@@ -177,7 +177,7 @@ void parse_command_line(int argc,
             break;
         case 'E':
             options->exclude_path = 1;
-            
+
             /* create linked list of excluding objects */
             if( (exclude_node = (struct exclude_path_list*) HDmalloc(sizeof(struct exclude_path_list))) == NULL)
             {
@@ -189,8 +189,8 @@ void parse_command_line(int argc,
             exclude_node->obj_path = (char*)opt_arg;
             exclude_node->obj_type = H5TRAV_TYPE_UNKNOWN;
             exclude_prev = exclude_head;
-            
-            if (NULL == exclude_head)            
+
+            if (NULL == exclude_head)
             {
                 exclude_head = exclude_node;
                 exclude_head->next = NULL;
@@ -202,7 +202,7 @@ void parse_command_line(int argc,
 
                 exclude_node->next = NULL;
                 exclude_prev->next = exclude_node;
-            }            
+            }
             break;
         case 'd':
             options->d=1;
@@ -458,7 +458,7 @@ check_d_input( const char *str )
 
 void usage(void)
 {
- printf("usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] \n");
+ printf("usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]\n");
  printf("  file1             File name of the first HDF5 file\n");
  printf("  file2             File name of the second HDF5 file\n");
  printf("  [obj1]            Name of an HDF5 object, in absolute path\n");
@@ -519,19 +519,22 @@ void usage(void)
  printf("   -n C, --count=C\n");
  printf("         Print differences up to C. C must be a positive integer.\n");
  printf("   -d D, --delta=D\n");
- printf("         Print difference if (|a-b| > D). D must be a positive number.\n");
+ printf("         Print difference if (|a-b| > D). D must be a positive number. Where a\n");
+ printf("         is the data point value in file1 and b is the data point value in file2.\n");
  printf("         Can not use with '-p' or '--use-system-epsilon'.\n");
  printf("   -p R, --relative=R\n");
- printf("         Print difference if (|(a-b)/b| > R). R must be a positive number.\n");
+ printf("         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a\n");
+ printf("         is the data point value in file1 and b is the data point value in file2.\n");
  printf("         Can not use with '-d' or '--use-system-epsilon'.\n");
  printf("   --use-system-epsilon\n");
- printf("         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.\n");
+ printf("         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a\n");
+ printf("         is the data point value in file1 and b is the data point value in file2.\n");
  printf("         If the system epsilon is not defined,one of the following predefined\n");
  printf("         values will be used:\n");
  printf("           FLT_EPSILON = 1.19209E-07 for floating-point type\n");
  printf("           DBL_EPSILON = 2.22045E-16 for double precision type\n");
  printf("         Can not use with '-p' or '-d'.\n");
- printf("   --exclude-path \"path\" \n");
+ printf("   --exclude-path \"path\"\n");
  printf("         Exclude the specified path to an object when comparing files or groups.\n");
  printf("         If a group is excluded, all member objects will also be excluded.\n");
  printf("         The specified path is excluded wherever it occurs.\n");
@@ -570,15 +573,15 @@ void usage(void)
  printf("\n");
 
  printf(" Object comparison:\n");
- printf("  1) Groups \n");
+ printf("  1) Groups\n");
  printf("      First compares the names of member objects (relative path, from the\n");
  printf("      specified group) and generates a report of objects that appear in only\n");
  printf("      one group or in both groups. Common objects are then compared recursively.\n");
- printf("  2) Datasets \n");
+ printf("  2) Datasets\n");
  printf("      Array rank and dimensions, datatypes, and data values are compared.\n");
- printf("  3) Datatypes \n");
+ printf("  3) Datatypes\n");
  printf("      The comparison is based on the return value of H5Tequal.\n");
- printf("  4) Symbolic links \n");
+ printf("  4) Symbolic links\n");
  printf("      The paths to the target objects are compared.\n");
  printf("      (The option --follow-symlinks overrides the default behavior when\n");
  printf("       symbolic links are compared.).\n");
diff --git a/tools/test/h5diff/testfiles/h5diff_10.txt b/tools/test/h5diff/testfiles/h5diff_10.txt
index a699f00..0a0ee22 100644
--- a/tools/test/h5diff/testfiles/h5diff_10.txt
+++ b/tools/test/h5diff/testfiles/h5diff_10.txt
@@ -1,4 +1,4 @@
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -59,19 +59,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -106,15 +109,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_600.txt b/tools/test/h5diff/testfiles/h5diff_600.txt
index 3c3ad9f..4362711 100644
--- a/tools/test/h5diff/testfiles/h5diff_600.txt
+++ b/tools/test/h5diff/testfiles/h5diff_600.txt
@@ -1,4 +1,4 @@
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -59,19 +59,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -106,15 +109,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_603.txt b/tools/test/h5diff/testfiles/h5diff_603.txt
index 087764a..9ab3204 100644
--- a/tools/test/h5diff/testfiles/h5diff_603.txt
+++ b/tools/test/h5diff/testfiles/h5diff_603.txt
@@ -1,5 +1,5 @@
 <-d -4> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_606.txt b/tools/test/h5diff/testfiles/h5diff_606.txt
index c31a67e..afe0e72 100644
--- a/tools/test/h5diff/testfiles/h5diff_606.txt
+++ b/tools/test/h5diff/testfiles/h5diff_606.txt
@@ -1,5 +1,5 @@
 <-d 0x1> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_612.txt b/tools/test/h5diff/testfiles/h5diff_612.txt
index 05318bd..97a1747 100644
--- a/tools/test/h5diff/testfiles/h5diff_612.txt
+++ b/tools/test/h5diff/testfiles/h5diff_612.txt
@@ -1,5 +1,5 @@
 <-p -4> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_615.txt b/tools/test/h5diff/testfiles/h5diff_615.txt
index fd756b3..78770f0 100644
--- a/tools/test/h5diff/testfiles/h5diff_615.txt
+++ b/tools/test/h5diff/testfiles/h5diff_615.txt
@@ -1,5 +1,5 @@
 <-p 0x1> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_621.txt b/tools/test/h5diff/testfiles/h5diff_621.txt
index fd8c680..b2a5881 100644
--- a/tools/test/h5diff/testfiles/h5diff_621.txt
+++ b/tools/test/h5diff/testfiles/h5diff_621.txt
@@ -1,5 +1,5 @@
 <-n -4> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_622.txt b/tools/test/h5diff/testfiles/h5diff_622.txt
index f0d38af..66a3025 100644
--- a/tools/test/h5diff/testfiles/h5diff_622.txt
+++ b/tools/test/h5diff/testfiles/h5diff_622.txt
@@ -1,5 +1,5 @@
 <-n 0> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_623.txt b/tools/test/h5diff/testfiles/h5diff_623.txt
index 4ab66a5..f9258d1 100644
--- a/tools/test/h5diff/testfiles/h5diff_623.txt
+++ b/tools/test/h5diff/testfiles/h5diff_623.txt
@@ -1,5 +1,5 @@
 <-n u> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).
diff --git a/tools/test/h5diff/testfiles/h5diff_624.txt b/tools/test/h5diff/testfiles/h5diff_624.txt
index f5e7ee3..57a4ddd 100644
--- a/tools/test/h5diff/testfiles/h5diff_624.txt
+++ b/tools/test/h5diff/testfiles/h5diff_624.txt
@@ -1,5 +1,5 @@
 <-n 0x1> is not a valid option
-usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]] 
+usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   file1             File name of the first HDF5 file
   file2             File name of the second HDF5 file
   [obj1]            Name of an HDF5 object, in absolute path
@@ -60,19 +60,22 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
    -n C, --count=C
          Print differences up to C. C must be a positive integer.
    -d D, --delta=D
-         Print difference if (|a-b| > D). D must be a positive number.
+         Print difference if (|a-b| > D). D must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-p' or '--use-system-epsilon'.
    -p R, --relative=R
-         Print difference if (|(a-b)/b| > R). R must be a positive number.
+         Print difference if (|(a-b)/b| > R). R must be a positive number. Where a
+         is the data point value in file1 and b is the data point value in file2.
          Can not use with '-d' or '--use-system-epsilon'.
    --use-system-epsilon
-         Print difference if (|a-b| > EPSILON), EPSILON is system defined value.
+         Print difference if (|a-b| > EPSILON), EPSILON is system defined value. Where a
+         is the data point value in file1 and b is the data point value in file2.
          If the system epsilon is not defined,one of the following predefined
          values will be used:
            FLT_EPSILON = 1.19209E-07 for floating-point type
            DBL_EPSILON = 2.22045E-16 for double precision type
          Can not use with '-p' or '-d'.
-   --exclude-path "path" 
+   --exclude-path "path"
          Exclude the specified path to an object when comparing files or groups.
          If a group is excluded, all member objects will also be excluded.
          The specified path is excluded wherever it occurs.
@@ -107,15 +110,15 @@ usage: h5diff [OPTIONS] file1 file2 [obj1[ obj2]]
   common objects.
 
  Object comparison:
-  1) Groups 
+  1) Groups
       First compares the names of member objects (relative path, from the
       specified group) and generates a report of objects that appear in only
       one group or in both groups. Common objects are then compared recursively.
-  2) Datasets 
+  2) Datasets
       Array rank and dimensions, datatypes, and data values are compared.
-  3) Datatypes 
+  3) Datatypes
       The comparison is based on the return value of H5Tequal.
-  4) Symbolic links 
+  4) Symbolic links
       The paths to the target objects are compared.
       (The option --follow-symlinks overrides the default behavior when
        symbolic links are compared.).