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| Note: Manual Read commands are not supported by all Parse-O-Matic applications.In general,if the application does some preprocessing of the data,the Manual Read commands are not available. This prevents the script from interfering with the underlying application.Manual Read commands are supported by the Parse-O-Matic Power Tool and Parse-O-Matic Advanced application,since it simply passes unaltered input data directly to the script via the $Data variable. |
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| Overview | ||||||||||||||||
| Most Parse-O-Matic applications read a file from top to bottom and feed the input file data to the script one record at a time.In most cases there is no need for Parse-O-Matic to behave differently.However, occasionally a parsing challenge arises in which the script writer needs to go backwards and forwards in a file,or needs to read in new data according to varying criteria.The Manual Read commands address these requirements. | ||||||||||||||||
| RecLenZero Scripts | ||||||||||||||||
| Manual Read commands are essential is when your script is figuring out for itself how many characters to get for each record.In such case,your script must configure the input file as binary and specify a record length of zero.This is known as a RecLenZero script.Here is a sample script. | ||||||||||||||||
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| With a record length of zero,the Parse-O-Matic application will never read a single byte from the input file. Thus,the first line of the Main step in a RecLenZero script is typically a ReadFor or ReadUntil command. These commands and others are described below. | ||||||||||||||||
| Using Manual Read for Standard Input File Types | ||||||||||||||||
| Most Manual Read commands work in the standard input modes (such as TextCR)and one of them (ReadNext)does not do anything in a RecLenZero script (i.e.when $CfgRecLen is set to zero).Once again,the crucial factor here is that these commands are not available in Parse-O-Matic applications that preprocess the input file in some way. | ||||||||||||||||
| Bookmark | ||||||||||||||||
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| ReadEOF | ||||||||||||||||
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| Since ReadEOF is a function,it cannot be used in a comparison command such as If or Begin.You can use the special variable $EndOfData for that purpose,or you can save the value of ReadEOF in a variable for later use.Both methods are useful for determining if the input file contains any more data. | ||||||||||||||||
| ReadFor | ||||||||||||||||
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| ReadNext | ||||||||||||||||
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| The ReadNext command updates $Data with the next record from the input file.This is helpful if you know for certain what kind of data will be in the next record and wish to process it at the current point in the script. ReadNext cannot be used in RecLenZero scripts,since when $CfgRecLen is set to zero Parse-O-Matic does not know how you are defining a “record ”.In such case you should use a command such as ReadUntil or ReadFor. |
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| ReadUntil | ||||||||||||||||
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| Rewind | ||||||||||||||||
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| Rewind ignores the sign of v1,so 123 and -123 are treated the same way.If you wish to move forward in the file,use the ReadFor command. Rewind resets the $EndOfData condition,but this needs to be done before the script ends or else you will move on to the FileDone step. (This page is part of the online user manual for Parse-O-Matic. Parse-O-Matic is a programmable parsing tool that can extract, manipulate, convert or mine existing data sources and turn them into importable data. For more information on Parse-O-Matic products and conversion services, please visit www.ParseOMatic.com) |
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