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Dataplot Vol 1 Vol 2

INQUIRE

Name:
    INQUIRE (LET)
Type:
    Let Subcommand
Purpose:
    Determine if a file exists.
Description:
    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.

Syntax 1:
    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.

Syntax 2:
    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.

Examples:
    LET IFLAG = INQUIRE BERGER1.DAT
    LET IFLAG = INQUIRE "MY FILES\SAMPLE.DAT"
    LET IFLAG = INQUIRE 44
Note:
    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
Note:
    File names are currently limited to 80 characters.
Default:
    None
Synonyms:
    None
Related Commands:
    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.
Applications:
    Data Input
Implementation Date:
    2016/02
    2016/06: Added support for unit numbers (Syntax 2)
Program 1:
     
    LET IFLAG = INQUIRE BERGER1.DAT
    IF IFLAG = 1
       READ BERGER1.DAT Y X BATCH
    ELSE
       PRINT "FILE BERGER1.DAT NOT FOUND"
    END OF IF
        
Program 2:
     
    PROBE IPL1NU
    LET UNIT = PROBEVAL
    LET IFLAG = INQUIRE ^IPL1NU
        

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Date created: 02/29/2016
Last updated: 06/10/2016

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