INQUIRE

INQUIRE (LET)

Let Subcommand

Determine if a file exists.

Dataplot commamnds that access pre-existing files (e.g., READ, CALL, LIST) have several specific restrictions.
1. A "." is required in the name to identify the string as a file.

   This restriction does not apply to the INQUIRE command.

2. File names that contain spaces or hyphens should be enclosed in quotes (").

   For the INQUIRE command, the quotes are optional.

3. Dataplot will first check for the file in the current directory as given. For operating systems where file names are case sensitive (Linux/Unix, Mac OS X), Dataplot will then check the name with all characters converted to lower case and with all characters converted to upper case. If the file is not found in the current directory, Dataplot will then check in the Dataplot auxillary directory (e.g., "/usr/local/lib/dataplot" under Linux or "C:\Program Files (x86)\NIST\DATAPLOT under Windows) for the file.

   The INQUIRE command does not do this. It checks the file name as given in the current directory only.

LET <iflag> = INQUIRE <file>
where <file> is the name of the desired file;
and <iflag> is a parameter that contains the file status.

If the file exists, the <iflag> parameter will be set to 1. If the file does not exist, the <iflag> parameter will be set to 0.

LET <iflag> = INQUIRE <unit>
where <unit> is an integer value between 1 and 99; and <iflag> is a parameter that contains the file status.

If the unit number is associated with a currently open file, the <iflag> parameter will be set to 1. If the unit number is not associated with a currently open file, the <iflag> parameter will be set to 0.

This syntax is typically used by the Dataplot developers for debugging purposes.

LET IFLAG = INQUIRE BERGER1.DAT
LET IFLAG = INQUIRE "MY FILES\SAMPLE.DAT"
LET IFLAG = INQUIRE 44

The specified file name should be given as a literal string. If the file name is stored in a string, you can use the "^" character as in
LET IFLAG = INQUIRE ^FNAME

File names are currently limited to 80 characters.

None

None

CLOSE	=	Close a file based on the associated unit number.
READ	=	Read data from file or terminal.
SERIAL READ	=	Read data serially from file or terminal.
CALL	=	Execute the commands stored in a file.
LIST	=	List the contents of a file.

Data Input

2016/02
2016/06: Added support for unit numbers (Syntax 2)

 
LET IFLAG = INQUIRE BERGER1.DAT
IF IFLAG = 1
   READ BERGER1.DAT Y X BATCH
ELSE
   PRINT "FILE BERGER1.DAT NOT FOUND"
END OF IF
    

 
PROBE IPL1NU
LET UNIT = PROBEVAL
LET IFLAG = INQUIRE ^IPL1NU