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  43 <H1 class="no-header">form_fieldtype 3x</H1>
  44 <PRE>
  45 <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>                                          <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
  46
  47
  48
  49
  50 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
  51        <STRONG>form_fieldtype</STRONG> - define validation-field types
  52
  53
  54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
  55        <STRONG>#include</STRONG> <STRONG>&lt;form.h&gt;</STRONG>
  56
  57        <STRONG>FIELDTYPE</STRONG> <STRONG>*new_fieldtype(</STRONG>
  58            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>field</EM><STRONG>_</STRONG><EM>check</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  59            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>char</EM><STRONG>_</STRONG><EM>check</EM><STRONG>)(int,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*));</STRONG>
  60        <STRONG>int</STRONG> <STRONG>free_fieldtype(FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>);</STRONG>
  61
  62        <STRONG>int</STRONG> <STRONG>set_fieldtype_arg(</STRONG>
  63            <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>,</STRONG>
  64            <STRONG>void</STRONG> <STRONG>*(*</STRONG> <STRONG>const</STRONG> <EM>make</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(va_list</STRONG> <STRONG>*),</STRONG>
  65            <STRONG>void</STRONG> <STRONG>*(*</STRONG> <STRONG>const</STRONG> <EM>copy</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  66            <STRONG>void</STRONG>  <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>free</EM><STRONG>_</STRONG><EM>arg</EM><STRONG>)(void</STRONG> <STRONG>*));</STRONG>
  67        <STRONG>int</STRONG> <STRONG>set_fieldtype_choice(</STRONG>
  68            <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>fieldtype</EM><STRONG>,</STRONG>
  69            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>next</EM><STRONG>_</STRONG><EM>choice</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*),</STRONG>
  70            <STRONG>bool</STRONG> <STRONG>(*</STRONG> <STRONG>const</STRONG> <EM>prev</EM><STRONG>_</STRONG><EM>choice</EM><STRONG>)(FIELD</STRONG> <STRONG>*,</STRONG> <STRONG>const</STRONG> <STRONG>void</STRONG> <STRONG>*));</STRONG>
  71
  72        <STRONG>FIELDTYPE</STRONG> <STRONG>*link_fieldtype(FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>type1</EM><STRONG>,</STRONG>
  73                                  <STRONG>FIELDTYPE</STRONG> <STRONG>*</STRONG><EM>type2</EM><STRONG>);</STRONG>
  74
  75
  76 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
  77
  78 </PRE><H3><a name="h3-new_fieldtype">new_fieldtype</a></H3><PRE>
  79        The  function  <STRONG>new_fieldtype</STRONG>  creates  a new field type usable for data
  80        validation.  Its parameters are function pointers:
  81
  82        <EM>field</EM><STRONG>_</STRONG><EM>check</EM>
  83             This function checks the validity of an entered data string  when-
  84             ever the user attempts to leave a field.  It has two arguments:
  85
  86             <STRONG>o</STRONG>   The  (FIELD  *) argument is passed in so the validation predi-
  87                 cate can see the field's buffer, sizes and other attributes.
  88
  89             <STRONG>o</STRONG>   The second argument  is  an  argument-block  structure,  about
  90                 which more below.
  91
  92        <EM>char</EM><STRONG>_</STRONG><EM>check</EM>
  93             This function validates input characters as they are entered.  The
  94             form library passes it the character to be checked and  a  pointer
  95             to an argument-block structure.
  96
  97
  98 </PRE><H3><a name="h3-free_fieldtype">free_fieldtype</a></H3><PRE>
  99        The <STRONG>free_fieldtype</STRONG> function frees the space allocated for a given vali-
 100        dation type by <STRONG>new_fieldtype</STRONG>.
 101
 102
 103 </PRE><H3><a name="h3-set_fieldtype_arg">set_fieldtype_arg</a></H3><PRE>
 104        The  function  <STRONG>set_fieldtype_arg</STRONG>  associates  three  storage-management
 105        functions with a field type:
 106
 107        <EM>make</EM><STRONG>_</STRONG><EM>arg</EM>
 108             This  function  is  automatically applied to the list of arguments
 109             you give <STRONG>set_field_type</STRONG> when attaching validation to a field.   It
 110             stores  the  arguments in an allocated argument-block object which
 111             is used when validating input.
 112
 113        <EM>copy</EM><STRONG>_</STRONG><EM>arg</EM>
 114             This function may be used by applications to copy argument-blocks.
 115
 116        <EM>free</EM><STRONG>_</STRONG><EM>arg</EM>
 117             Frees an argument-block structure.
 118
 119        You must supply the <EM>make</EM><STRONG>_</STRONG><EM>arg</EM> function.  The other two are optional: you
 120        may  supply NULL for them.  In this case, the form library assumes that
 121        <EM>make</EM><STRONG>_</STRONG><EM>arg</EM> does not allocate memory but simply loads the argument into  a
 122        single scalar value.
 123
 124
 125 </PRE><H3><a name="h3-set_fieldtype_choice">set_fieldtype_choice</a></H3><PRE>
 126        The  form  driver  requests  <STRONG>REQ_NEXT_CHOICE</STRONG> and <STRONG>REQ_PREV_CHOICE</STRONG> assume
 127        that the possible values of a field form an ordered  set,  and  provide
 128        the forms user with a way to move through the set.
 129
 130        The  <STRONG>set_fieldtype_choice</STRONG>  function  allows forms programmers to define
 131        successor and predecessor functions for the field  type.   These  func-
 132        tions  take  the field pointer and an argument-block structure as argu-
 133        ments.
 134
 135
 136 </PRE><H3><a name="h3-link_fieldtype">link_fieldtype</a></H3><PRE>
 137        The function <STRONG>link_fieldtype</STRONG> creates a new field type from the two given
 138        types.  They are connected by an logical 'OR'.
 139
 140
 141 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
 142        The  pointer-valued  routines  return  NULL  on  error.  They set <STRONG>errno</STRONG>
 143        according to their success:
 144
 145        <STRONG>E_OK</STRONG> The routine succeeded.
 146
 147        <STRONG>E_BAD_ARGUMENT</STRONG>
 148             Routine detected an incorrect or out-of-range argument.
 149
 150        <STRONG>E_SYSTEM_ERROR</STRONG>
 151             System error occurred, e.g., malloc failure.
 152
 153        The integer-valued routines return one of the following codes on error:
 154
 155        <STRONG>E_OK</STRONG> The routine succeeded.
 156
 157        <STRONG>E_BAD_ARGUMENT</STRONG>
 158             Routine detected an incorrect or out-of-range argument.
 159
 160        <STRONG>E_CONNECTED</STRONG>
 161             The field is already connected to a form.
 162
 163        <STRONG>E_CURRENT</STRONG>
 164             The field is the current field.
 165
 166        <STRONG>E_SYSTEM_ERROR</STRONG>
 167             System error occurred (see <STRONG>errno(3)</STRONG>).
 168
 169
 170 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
 171        <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>, <STRONG><A HREF="form_field_validation.3x.html">form_field_validation(3x)</A></STRONG>.
 172
 173
 174 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
 175        The  header  file  <STRONG>&lt;form.h&gt;</STRONG>  automatically  includes  the  header  file
 176        <STRONG>&lt;curses.h&gt;</STRONG>.
 177
 178
 179 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
 180        These  routines emulate the System V forms library.  They were not sup-
 181        ported on Version 7 or BSD versions.
 182
 183
 184 </PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
 185        Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
 186        Raymond.
 187
 188
 189
 190                                                             <STRONG><A HREF="form_fieldtype.3x.html">form_fieldtype(3x)</A></STRONG>
 191 </PRE>
 192 <div class="nav">
 193 <ul>
 194 <li><a href="#h2-NAME">NAME</a></li>
 195 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
 196 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
 197 <ul>
 198 <li><a href="#h3-new_fieldtype">new_fieldtype</a></li>
 199 <li><a href="#h3-free_fieldtype">free_fieldtype</a></li>
 200 <li><a href="#h3-set_fieldtype_arg">set_fieldtype_arg</a></li>
 201 <li><a href="#h3-set_fieldtype_choice">set_fieldtype_choice</a></li>
 202 <li><a href="#h3-link_fieldtype">link_fieldtype</a></li>
 203 </ul>
 204 </li>
 205 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
 206 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
 207 <li><a href="#h2-NOTES">NOTES</a></li>
 208 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
 209 <li><a href="#h2-AUTHORS">AUTHORS</a></li>
 210 </ul>
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