INQUIRE

 Returns information about specified properties of a file or of a
 logical unit on which a file might be opened.  The unit need not
 exist, nor need it be connected to a file.  If the unit is
 connected to a file, the inquiry encompasses both the connection
 and the file.  Statement format:

  Inquiring by File:

    INQUIRE (FILE=fi [,ERR=lbl][,IOSTAT=ivar][,DEFAULTFILE=def], flist)

  Inquiring by Unit:

    INQUIRE ([UNIT=]u [,ERR=lbl][,IOSTAT=ivar], flist)

  Inquiring by Output List:

    INQUIRE (IOLENGTH=len) olist

    fi     Is a scalar default character expression
           specifying the name of the file for inquiry.

    lbl    Is the label of the branch target statement 
           that receives control if an error occurs.

    var    Is a scalar integer variable that is defined 
           as a positive integer if an error occurs and 
           zero if no error occurs.

    def    Is a scalar default character expression specifying
           a default file pathname (or file specification) string.  

    flist  Is one or more inquiry specifiers. Each specifier 
           can appear only once.  Information about the 
           individual specifiers is available under the 
           subtopic headings listed at the end of this Help 
           topic.

    u      Is an integer variable or constant specifying the 
           logical unit number of the file, optionally prefaced 
           by UNIT=.  UNIT= is required if unit is not the 
           first I/O specifier.  The unit does not have to 
           exist, nor does it need to be connected to a file.
           If the unit is connected to a file, the inquiry 
           encompasses both the connection and the file.

    len    Is a scalar integer variable indicating 
           the number of bytes of data that would result from 
           using "olist" in an unformatted output statement.

    olist  Is a list of one or more output items.

 FILE=fi, UNIT=u, ERR=lbl, and IOSTAT=var can appear anywhere within
 the parentheses following INQUIRE.  However, if the UNIT keyword is
 omitted, the unit specifier ("u") must be the first parameter in
 the list.

 An INQUIRE statement may be executed before, during, or after the
 connection of a file to a unit.  The values assigned by the
 statement are those that are current when the INQUIRE statement
 executes.

 To get file characteristics, specify the INQUIRE statement after
 opening the file.  (File characteristics are stored in the file
 header.)

Additional information available:

ACCESS          ACTION          BLANK           BLOCKSIZE       BUFFERED
CARRIAGECONTROL CONVERT         DELIM           DIRECT          ERR
EXIST           FORM            FORMATTED       IOSTAT          KEYED
NAME            NAMED           NEXTREC         NUMBER          OPENED
ORGANIZATION    PAD             POSITION        READ            READWRITE
RECL            RECORDTYPE      SEQUENTIAL      UNFORMATTED     WRITE