form_field_validation(3x)

1form_field_validation(3X)                            form_field_validation(3X)
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NAME

6       form_field_validation - data type validation for fields
7

SYNOPSIS

9       #include <form.h>
10       int set_field_type(FIELD *field, FIELDTYPE *type, ...);
11       FIELDTYPE *field_type(const FIELD *field);
12       void *field_arg(const FIELD *field);
13
14       FIELDTYPE *TYPE_ALNUM;
15       FIELDTYPE *TYPE_ALPHA;
16       FIELDTYPE *TYPE_ENUM;
17       FIELDTYPE *TYPE_INTEGER;
18       FIELDTYPE *TYPE_NUMERIC;
19       FIELDTYPE *TYPE_REGEXP;
20       FIELDTYPE *TYPE_IPV4;
21

DESCRIPTION

23       The  function  set_field_type  declares  a  data  type for a given form
24       field.  This is the type checked by validation functions.   The  prede‐
25       fined types are as follows:
26
27       TYPE_ALNUM
28            Alphanumeric data.  Requires a third int argument, a minimum field
29            width.
30
31       TYPE_ALPHA
32            Character data.  Requires a third int argument,  a  minimum  field
33            width.
34
35       TYPE_ENUM
36            Accept  one  of  a  specified set of strings.  Requires additional
37            parameters:
38
39            ·   a third (char **) argument pointing to a string list;
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41            ·   a fourth int flag argument to enable case-sensitivity;
42
43            ·   and a fifth int flag argument  specifying  whether  a  partial
44                match  must  be  a  unique one.  If this flag is off, a prefix
45                matches the first of any set of more than  one  list  elements
46                with that prefix.
47
48                The library copies the string list, so you may use a list that
49                lives in automatic variables on the stack.
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51       TYPE_INTEGER
52            Integer data, parsable to an integer by atoi(3).   Requires  addi‐
53            tional parameters:
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55            ·   a third int argument controlling the precision,
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57            ·   a fourth long argument constraining minimum value,
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59            ·   and  a  fifth long constraining maximum value.  If the maximum
60                value is less than or equal to the minimum value, the range is
61                simply  ignored.   On  return,  the  field buffer is formatted
62                according to the printf format specification “.*ld”, where the
63                “*” is replaced by the precision argument.
64
65                For details of the precision handling see printf(3).
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67       TYPE_NUMERIC
68            Numeric data (may have a decimal-point part).  This requires addi‐
69            tional parameters:
70
71            ·   a third int argument controlling the precision,
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73            ·   a fourth double argument constraining minimum value,
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75            ·   and a fifth double constraining maximum value.  If your system
76                supports  locales, the decimal point character must be the one
77                specified by your locale.  If the maximum value is  less  than
78                or equal to the minimum value, the range is simply ignored.
79
80                On  return,  the  field  buffer  is formatted according to the
81                printf format specification “.*f”, where the “*”  is  replaced
82                by the precision argument.
83
84                For details of the precision handling see printf(3).
85
86       TYPE_REGEXP
87            Regular  expression  data.  Requires a regular expression (char *)
88            third argument.  The data  is  valid  if  the  regular  expression
89            matches it.
90
91            Regular expressions are in the format of regcomp and regexec.
92
93            The  regular  expression  must match the whole field.  If you have
94            for example, an eight character wide field, a  regular  expression
95            "^[0-9]*$"  always means that you have to fill all eight positions
96            with digits.  If you want to allow fewer digits, you may  use  for
97            example  "^[0-9]*  *$" which is good for trailing spaces (up to an
98            empty field), or "^ *[0-9]* *$" which  is  good  for  leading  and
99            trailing spaces around the digits.
100
101       TYPE_IPV4
102            An  Internet  Protocol  Version 4 address.  This requires no addi‐
103            tional argument.  The library checks whether or not the buffer has
104            the form a.b.c.d, where a,b,c and d are numbers between 0 and 255.
105            Trailing blanks in the buffer are ignored.  The address itself  is
106            not validated.
107
108            This is an ncurses extension; this field type may not be available
109            in other curses implementations.
110
111       It is possible to set up new programmer-defined field types.   See  the
112       form_fieldtype(3X) manual page.
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RETURN VALUE

115       The functions field_type and field_arg return NULL on error.  The func‐
116       tion set_field_type returns one of the following:
117
118       E_OK The routine succeeded.
119
120       E_SYSTEM_ERROR
121            System error occurred (see errno(3)).
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NOTES

127       The  header  file  <form.h>  automatically  includes  the  header  file
128       <curses.h>.
129

PORTABILITY

131       These  routines emulate the System V forms library.  They were not sup‐
132       ported on Version 7 or BSD versions.
133

AUTHORS

135       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
136       Raymond.
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140                                                     form_field_validation(3X)