FILESCAN statement

Purpose

Rapidly scan a file opened for INPUT or BINARY mode, in order to obtain size information about variable length string data.

Syntax

FILESCAN [#] fnum&, RECORDS TO y& [, WIDTH TO x&]

Remarks

FILESCAN assigns a count of the lines/records/strings to y&, and if the WIDTH clause is specified, the length of the longest string to x&.

In INPUT mode, it is assumed the data is standard text, with lines delimited by a CR/LF ($CRLF) pair.  FILESCAN stops reading the file if it encounters an "end of file" (EOF) marker byte (CHR$(26) or $EOF).  Text that occurs after the last CR/LF but before the EOF is considered the last record of the file.  Use the LINE  INPUT# statement to read a complete text file into an array.

In BINARY mode, it is assumed the file was written in the PowerBASIC and/or VB packed string format using PUT of an entire string array.  If a string is shorter than 65535 bytes, a 2-byte length WORD is followed by the string data.  If a string is equal to or longer than 65535 bytes, a 2-byte value of 65535 is followed by a length DWORD value, then finally the string data.

Use the GET statement to read a complete binary file into an array.

Restrictions

If FILESCAN is applied to other file formats, the results are undefined.

See also

GET, GET$, GET$$, LINE  INPUT#, PUT, PUT$, PUT$$

Example

OPEN "datafile.dat" FOR INPUT AS #1

FILESCAN #1, RECORDS TO count&

DIM TheData(1 TO count&) AS STRING

LINE INPUT #1, TheData() TO count&

CLOSE #1

Result

The entire text file comprising y& lines is read into the string array.