picfld

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PICFLD - generate a field list using expressions

Process Name	Menu Path	Link to Command Table
PICFLD	Data ribbon \| Data Tools \| Tables \| Select Fields	Click here

Introduction
Files, Fields and Parameters
Notes
Example
Errors

Introduction

Writes field names to an output file if the field names in the input file match the given pattern expressions.

How to use

Expression Syntax

In the following text all keywords are capitalized. When running PICFLD, any keyword may be entered in either uppercase or lowercase and abbreviated to its first three (or more) characters.

The syntax of a pattern matching expression is:

	[FILE]	[REGEXP]	<pattern>
or	FIELD	[REGEXP]	<pattern>
or	FIELD	<kind>
or	FIELD	[REGEXP]	<pattern> ,	<kind>

The keyword "FILE" is optional. If a pattern is to be matched against field names, the keyword "FIELD" must be included. The field "kind" will be matched against the type (numeric or alphanumeric) and storage class (explicit or implicit) of the fields in any file.

The keyword "REGEXP" is normally omitted, in which case "pattern" may consist of literal characters to be matched, or one of the following elements:

?	Any single character
*	Wildcard. A group of zero or more characters
[...]	Any one of the characters enclosed in the square brackets. The short hand notation "a-z" means any lowercase letter; refer to the examples below for more details.
[^...]	Any character except one of these

The special meaning of a character (e.g. "*") is lost if the character is preceded by "\", hence the match a literal "*", use "\*". Quotes (double or single) may be used to enclose patterns if desired.

Where a pattern is applied to file names, lowercase letters are translated into uppercase before the pattern is used.

If the keyword "REGEXP" is used, the pattern specifies a full regular expression. Regular expressions allow advanced users to make more complex selections than are possible by using the pattern elements specified above.

A regular expression in PICDIR may contain the following elements.

%	Matches the beginning of the file or field name
$	Matches the end of the file or field name
*	Zero or more occurrences of the preceding pattern element.
?	As above
[...]	As above
[^...]	As above

The "kind" is a list of field type or storage class specifiers, separated by commas. Keywords that specify field type are "NUMERIC" or "ALPHANUMERIC". Storage classes are "EXPLICIT" or "IMPLICIT". Of course, any of these may be abbreviated to three (or more) letters.

If more than one type or class keyword is given, the last one specified is used.

Concatenation of Expressions

The result of a pattern matching expression is either TRUE or FALSE. Any result may be inverted by preceding the expression by the keyword "NOT" (e.g. "NOT XPICRT,IMPLICIT"). Two expressions may be joined together by "AND" or "OR" operators. The result is another expression. The "AND" operator has higher precedence than "OR". Parentheses (brackets) may be used to override the normal order of evaluation of expressions.

Files, Fields and Parameters

Input Files

Name	Description	I/O Status	Required	Type
IN	Input file, from which fields are to be selected.	Input	Yes	Table

Output Files

Name	I/O Status	Required	Type	Description
OUT	Output	Yes	Undefined	Output file, containing selected field names.

Fields

Name	Description	Source	Required	Type	Default
FIELDNAM	Optional name for the field in OUT that is to contain the selected field names. The default is "FIELDNAM".	OUT	No	Character	FIELDNAM

Parameters

Name

Description

Required

Default

Range

Values

Option	Description
0	No display of matching field names >0 Display field names as they are matched. (0)

0,1

APPEND

If set to 1 then selected field names will be appended to the OUT file, provided it exists and has a valid DD (0).

0,1

SORT

If set to 1 then the output file will be sorted after all field names have been written to it (0).

0,1

Notes

No additional notes.

Example

Select all three-letter fields that begin with "Au" or "AU". The fields must be numeric.

TEST>FIELD A[uU]?,NUMERIC END

Select all explicit, numeric fields from a model file, except for the "standard" ones.

TEST>NUMERIC,EXPLICIT AND NOT
TEST>([XYZ]C OR [XYZ]INC OR IJK) END

Note that brackets are required to associate the "NOT" with all the seven standard fields.

Error and Warning Messages

Message	Description	Solution
>>> WARNING: Cannot append to file ffffffff. A new file will be created	Cannot append fieldnames to the file specified as &OUT. Check the file name given. A new &OUT file will be created.

>>> ERROR: Files have different DDs, cannot append	File specified in pattern matching expression and the file specified as &OUT have different DDs. Fatal; the process is exited.

>>> ERROR: Unexpected execution error	Fatal; the process is exited.

>>> ERROR: Illegal instruction found	Fatal; the process is exited.

>>> SYNTAX ERROR AT " "	Syntax of pattern matching expression is incorrect. Fatal; the process is exited.