- The function set_field_type declares a data type for a given form
- field. This is the type checked by validation functions. The prede-
- fined types are as follows:
+ By default, no validation is done on form fields. You can associate a
+ form with with a fieldtype, making the form library validate input.
- TYPE_ALNUM
- Alphanumeric data. Requires a third int argument, a minimum field
- width.
- TYPE_ALPHA
- Character data. Requires a third int argument, a minimum field
- width.
+
+ Returns a pointer to the field's argument block. The argumentblock is
+ an opaque structure containing a copy of the arguments provided in a
+ set_field_type call.
- TYPE_ENUM
- Accept one of a specified set of strings. Requires additional
- parameters:
- o a third (char**) argument pointing to a string list;
+
+ Returns a pointer to the fieldtype associated with the form field,
+ i.e., by calling set_field_type.
- o a fourth int flag argument to enable case-sensitivity;
- o and a fifth int flag argument specifying whether a partial
- match must be a unique one. If this flag is off, a prefix
- matches the first of any set of more than one list elements
- with that prefix.
+
+ The function set_field_type associates a field type with a given form
+ field. This is the type checked by validation functions. Most field
+ types are configurable, via arguments which the caller provides when
+ calling set_field_type.
- The library copies the string list, so you may use a list that
- lives in automatic variables on the stack.
+ Several field types are predefined by the form library.
- TYPE_INTEGER
- Integer data, parsable to an integer by atoi(3). Requires addi-
- tional parameters:
- o a third int argument controlling the precision,
+
+ It is possible to set up new programmer-defined field types. Field
+ types are implemented via the FIELDTYPE data structure, which contains
+ several pointers to functions.
- o a fourth long argument constraining minimum value,
+ See the form_fieldtype(3x) manual page, which describes functions which
+ can be used to construct a field-type dynamically.
- o and a fifth long constraining maximum value. If the maximum
- value is less than or equal to the minimum value, the range is
- simply ignored. On return, the field buffer is formatted
- according to the printf format specification ".*ld", where the
- "*" is replaced by the precision argument.
+ The predefined types are as follows:
- For details of the precision handling see printf(3).
- TYPE_NUMERIC
- Numeric data (may have a decimal-point part). This requires addi-
- tional parameters:
+
+ Alphanumeric data. Required parameter:
- o a third int argument controlling the precision,
+ o a third int argument, a minimum field width.
- o a fourth double argument constraining minimum value,
- o and a fifth double constraining maximum value. If your system
- supports locales, the decimal point character must be the one
- specified by your locale. If the maximum value is less than
- or equal to the minimum value, the range is simply ignored.
+
+ Character data. Required parameter:
- On return, the field buffer is formatted according to the
- printf format specification ".*f", where the "*" is replaced
- by the precision argument.
+ o a third int argument, a minimum field width.
- For details of the precision handling see printf(3).
- TYPE_REGEXP
- Regular expression data. Requires a regular expression (char*)
- third argument. The data is valid if the regular expression
- matches it.
+
+ Accept one of a specified set of strings. Required parameters:
- Regular expressions are in the format of regcomp and regexec.
+ o a third (char**) argument pointing to a string list;
- The regular expression must match the whole field. If you have
- for example, an eight character wide field, a regular expression
- "^[0-9]*$" always means that you have to fill all eight positions
- with digits. If you want to allow fewer digits, you may use for
- example "^[0-9]* *$" which is good for trailing spaces (up to an
- empty field), or "^ *[0-9]* *$" which is good for leading and
- trailing spaces around the digits.
+ o a fourth int flag argument to enable case-sensitivity;
- TYPE_IPV4
- An Internet Protocol Version 4 address. This requires no addi-
- tional argument. The library checks whether or not the buffer has
- the form a.b.c.d, where a,b,c and d are numbers between 0 and 255.
- Trailing blanks in the buffer are ignored. The address itself is
- not validated.
+ o a fifth int flag argument specifying whether a partial match must
+ be a unique one. If this flag is off, a prefix matches the first
+ of any set of more than one list elements with that prefix.
- This is an ncurses extension; this field type may not be available
- in other curses implementations.
+ The library copies the string list, so you may use a list that lives in
+ automatic variables on the stack.
- It is possible to set up new programmer-defined field types. See the
- form_fieldtype(3x) manual page.
+
- The functions field_type and field_arg return NULL on error. The func-
- tion set_field_type returns one of the following:
+ o a third int argument controlling the precision,
- E_OK The routine succeeded.
+ o a fourth long argument constraining minimum value,
- E_SYSTEM_ERROR
- System error occurred (see errno(3)).
+ o a fifth long constraining maximum value. If the maximum value is
+ less than or equal to the minimum value, the range is simply
+ ignored.
+ On return, the field buffer is formatted according to the printf format
+ specification ".*ld", where the "*" is replaced by the precision
+ argument.
+
+ For details of the precision handling see printf(3).
+
+
+
+ Numeric data (may have a decimal-point part). Required parameters:
+
+ o a third int argument controlling the precision,
+
+ o a fourth double argument constraining minimum value,
+
+ o and a fifth double constraining maximum value. If your system
+ supports locales, the decimal point character must be the one
+ specified by your locale. If the maximum value is less than or
+ equal to the minimum value, the range is simply ignored.
+
+ On return, the field buffer is formatted according to the printf format
+ specification ".*f", where the "*" is replaced by the precision
+ argument.
+
+ For details of the precision handling see printf(3).
+
+
+
+ Regular expression data. Required parameter:
+
+ o a third argument, a regular expression (char*) string. The data
+ is valid if the regular expression matches it.
+
+ Regular expressions are in the format of regcomp and regexec.
+
+ The regular expression must match the whole field. If you have for
+ example, an eight character wide field, a regular expression "^[0-9]*$"
+ always means that you have to fill all eight positions with digits. If
+ you want to allow fewer digits, you may use for example "^[0-9]* *$"
+ which is good for trailing spaces (up to an empty field), or "^ *[0-9]*
+ *$" which is good for leading and trailing spaces around the digits.
-
- The header file <form.h> automatically includes the header file
- <curses.h>.
+ o none
+
+ The form library checks whether or not the buffer has the form a.b.c.d,
+ where a, b, c, and d are numbers in the range 0 to 255. Trailing
+ blanks in the buffer are ignored. The address itself is not validated.
+
+ This is an ncurses extension; this field type may not be available in
+ other curses implementations.
+
+
+
+ The functions field_type and field_arg return NULL on error. The
+ function set_field_type returns one of the following:
+
+ E_OK The routine succeeded.
+
+ E_SYSTEM_ERROR
+ System error occurred (see errno(3)).
- These routines emulate the System V forms library. They were not sup-
- ported on Version 7 or BSD versions.
+ These routines emulate the System V forms library. They were not
+ supported on Version 7 or BSD versions.