Re: CL program to check if folder exists in IFS

Glenn,

The access() API works fine for directories.

When you receive a -1, you can call an API called __errno() (that's two underscores, then 'errno') which returns a pointer. That pointer points to an integer containing the error number that occurred.

The error number corresponds to a msgid in the QCPFMSG file starting with 'CPE', so if the error number is '1234', you could look up CPE1234 to find out what the error means.

Taking a quick glance at your code -- it looks wrong to me. The 2nd parameter (mode) of the access() API must be an integer passed by value. You are passing a character field by reference. So this probably won't work.

Are you doing this in order to achieve compatibility with a very old version of IBM i? (Off the top of my head, the *BYVAL feature was added in V5R3... but don't quote me on that) If so, you may not be able to use access() from CL.

But for newer releases, you can just use the *INT data type and the *BYVAL option whne calling the API.

I could code up an example if you like.



On 4/7/2015 4:12 PM, Glenn Gundermann wrote:

Hi all,

Does the access api work for a folder or does it have to be a file?

I was hoping it works for a folder but the information in the IBM Knowledge
Center says a file.

If I pass in a folder name that I know exists in the IFS, -1 is returned,
which means failure. Can I debug the access api to see why?

If access is only for files, what is the best way to check if a folder
exists? Use the open api?

Here's the relevant part of the code I am trying.

DCL VAR(&PATHNULTRM) TYPE(*CHAR) LEN(513) /* Allows +
for path of 512 bytes + extra character for null +
termination. */
DCL VAR(&MODE) TYPE(*CHAR) LEN(4)
DCL VAR(&RTNVAL) TYPE(*INT) /* 0=file exists, +
-1=file does not exist */
DCL VAR(&NULL) TYPE(*CHAR) LEN(1) VALUE(X'00')

/* Check if folder for source lib exists. */
/* Call IBM API. */
/* &RTNVAL: 0=file exists, -1=file does not exist. */
CHGVAR VAR(%BIN(&MODE)) VALUE(0) /* Set access mode +
to test if the file exists - F_OK */
CHGVAR VAR(&PATHNULTRM) VALUE('/ARCHIVED_SOURCE/' +
*CAT %TRIM(&SRCLIB) *CAT &NULL)
CALLPRC PRC('access') PARM((&PATHNULTRM) (&MODE)) +
RTNVAL(&RTNVAL)
/* Folder for source lib does not exist so make it. */
IF COND(&RTNVAL = -1) THEN(DO)
CHGVAR VAR(&DIR) VALUE('/ARCHIVED_SOURCE/' *CAT +
%TRIM(&SRCLIB))
MKDIR DIR(&DIR)
ENDDO


Yours truly,

Glenn Gundermann
Email: glenn.gundermann@xxxxxxxxx
Cell: (416) 317-3144