How to get/query the list of files in a folder from Envision

Say you have a list of file in HOLD_SHARED_MYFOLDER directory in Colleague, and you want to read in the list of files in MYFOLDER and do something with them, maybe read or write or both.

What you need is read/write access to MYFOLDER. Your admin should know how to set it up, and a VOC entry should already be created for it. 

In Colleague Studio, use the following code to get back a list of files inside MYFOLDER directory:

X.STMT = 'SELECT HOLD_SHARED_MYFOLDER'
CALL S.EXECUTE(X.STMT)
XL.FILES.NAME = ''
CALL S.READLIST(XL.FILES.NAME,0,X.STATUS)
CONVERT @FM:@SM:@VM:@AM TO @VM:@VM:@VM:@VM IN XL.FILES.NAME

Now you will have all the files' names in MYFOLDER populated in XL.FILES.NAME. To open each file up, you iterate them with S.OPEN.SEQ subroutine

FOR X = 1 to DCOUNT(XL.FILES.NAME, @VM)
   * Open the file
   CALL S.OPEN.SEQ("HOLD_SHARED_MYFOLDER", XL.FILES.NAME<1,X>, X, "R", X.ERROR.MSG)
   * Read from the file
   CALL S.READ.SEQ(X.TEXT, X.EOF, X, X.ERROR, X.MSG)
   * Close the file
   CALL S.CLOSE.SEQ(X, X.ERROR, X.MSG)
NEXT X

Notes on S.EXECUTE subroutine

S.EXECUTE will execute a sentence to perform operations, such as a select statement against the database. This is Datatel's version of the Unibasic EXECUTE command (you can type HELP EXECUTE at the colon prompt for additional information about EXECUTE). Since EXECUTE only works for Unidata clients, we encourage people to use S.EXECUTE in its place.

UniQuery-syntax statements can be used with S.EXECUTE on any underlying database. These statements, when used with S.EXECUTE, will be converted by Datatel's underlying MIO components to the native database query language for executing the select statement.

There is only one argument for this subroutine:
A.STMT Input only The statement to execute; the format of this statement should be:
[<options>] <command> [<arguments>]

<options> are optional; it is a list of zero or more options that are separated by spaces, each of which begins with a dash ('-') character. Valid options are:

-H = Hush the output that may be generated by the command being executed; for example, the 'n records selected' message when a select statement is executed
-NM = Do not map SELECT/SSELECT commands to MIOSEL/MIOSELS; this option is NOT recommended for use unless you are certain the file being selected exists on the application server AND you are certain that the -NM option is necessary
-C = Capture output from the command in the CAPTURED.OUTPUT common variable
-DB = Force debug mode ON for execution of S.EXECUTE; same effect as entering S.EXECUTE in UTDB screen
-DH = Only valid on Distributed UniData deployments; Execute command on database server ('datahome')

<command> is a query language command such as SELECT

<arguments> are optional; is a string that contains arguments for the command (if applicable)

Example:
X.STMT = 'MIOSEL PERSON WITH LAST.NAME = 'Smith''
CALL S.EXECUTE (X.STMT)
FOR_EACH SELECTED ID
<code>
END_EACH SELECTED ID

The X.STMT line sets up the 'sentence' to execute. The next line that calls S.EXECUTE executes the statement. We now have an active list of PERSON records, of which we can use in the following FOR_EACH loop.

Bug when running uniquery

The following query failed to run:

X.STMT = "SELECT X.TABLE WITH X.FIELD1 EQ 'someValue' SAVING X.FIELD2"

CALL S.EXECUTE(X.STMT)

CALL S.READLIST(A.OUT, '', A.OUT2)

When using the SAVING keyword, the query has to return some data for it to work. If there is no X.FIELD1 with value equals to "somevalue" in table X.TABLE, the query will fail and return random data. I think it's whatever is in the active list 0. In this case, A.OUT will have random data and A.OUT2 will be '1'.