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IFS Path Validation
Posted: Tue May 09, 2023 6:49 am
by bbunney
Can I use the access API to verify that an IFS Path exists as opposed to verifying a path and file exists? If not should I use the CHDIR command instead or maybe use the open source CHKLNK command? Thanks.
Code: Select all
Dcl-Pr access Int(10:0) ExtProc('access');
pathptr Pointer Value;
mode Int(10:0) Value;
End-Pr;
pathname = '/home/property/documents' + x'00';
pathptr = %addr(pathname);
pathok = 0;
Path_Exists = access(pathptr:pathok);
If Path_Exists = 0;
// Path Found
Else;
// Path not Found
EndIf;
Re: IFS Path Validation
Posted: Tue May 09, 2023 2:51 pm
by jonboy49
Personally, I would use opendir() for this task as it checks for both existence and premissions.
Re: IFS Path Validation
Posted: Tue May 09, 2023 6:04 pm
by bbunney
Thank you! I will do that. I'm assuming that if the path is found that I would need to execute a closedir then. My program uses the open, write, close and unlink API's to write a file to the IFS if the path is valid.
Re: IFS Path Validation
Posted: Wed May 10, 2023 1:43 pm
by jonboy49
The other option would be stat() - which would avoid the close but may have a higher overhead.
From googling around, there appear to be some versions of access() that will work with directories but it is unclear to me which is what! Scott probably knows - he is far more knowledgeable about all things C than I am.
Re: IFS Path Validation
Posted: Wed May 10, 2023 5:17 pm
by Scott Klement
access() should work fine. Not sure that I understand what is being asked... what is the difference between a "path exists" vs "path and file exists"?
If its important to determine if the object is a directory (vs. a file) then I would use stat() and check the IS_DIR bit of the mode. (Which will cover all of the "directory-like" objects, such as *DIR, *DDIR, *FLR and *FILE)
I wouldn't use anything that creates an object like mkdir or open, or anything that changes your current state like chdir unless you actually want to create an object or change your current state, respectively. These add overhead, its just a waste if you don't need it. Plus... why? Checking existence with access() is actually easier to code -- and stat() is also relatively easy and much more powerful. Why use something not designed for the purpose?
Also, your RPG code that calls stat could be much simpler, unless you need to run it on V3R2/V3R7? Why aren't you taking advantage of options(*string)?
Re: IFS Path Validation
Posted: Thu May 11, 2023 4:18 pm
by bbunney
The code I put in my post isn't my code. It was code I googled before I wrote my code. I'm developing a program that will be passed an IFS Path, document type (JSON, XML, TXT or PDF), file name prefix and a data string. I want to validate the path first, the file name will be unique as a sequence number is generated for each file from a data area. I coded jonboy's first suggestion because I have to code to V7.2 even thought the development box is on V7.4 as I have to wait until over 60 production LPAR's are upgraded or I would have used a SQL Table for this. A will replace opendir() and closedir() with access() then. Thank you! But I have another issue now. When I go to write an XML string to the IFS, two characters are added to the front of the string causing 2 characters what appears to be a tab and a ' '. So something must be wrong with either my open() or write() statement. Could you take a look please? Thanks!
Code: Select all
Dcl-S l_fd Int(10:0);
Dcl-S l_data VarChar(64512);
Dcl-S l_IFSFile VarChar(200);
Dcl-C O_WRONLY 2;
Dcl-C O_CREAT 8;
Dcl-C O_TRUNC 64;
Dcl-C O_CCSID 32;
Dcl-C O_TEXTDATA 16777216;
Dcl-C O_TEXT_CREAT 33554432;
Dcl-C RW 6;
Dcl-C R 4;
Dcl-C OWNER 64;
Dcl-C GROUP 8;
Dcl-Pr OpenFile Int(10:0) ExtProc('open');
FileName Pointer Value Options(*string);
OpenFlags Int(10:0) Value;
Mode Uns(10:0) Value Options(*nopass);
Ccsid Uns(10:0) Value Options(*nopass);
TxtCreatId Uns(10:0) Value Options(*nopass);
End-Pr;
Dcl-Pr WriteFile Int(10:0) Extproc('write');
Fildes Int(10:0) Value;
Buf Pointer Value;
Nbyte Uns(10:0) Value;
End-Pr;
Dcl-Pr CloseFile Int(10:0) ExtProc('close');
Fildes Int(10:0) Value;
End-Pr;
l_IFSFile = %Trim(Ds_IFSParm.IFSPath) + '/' +
l_PropCodeLower + %Trim(Ds_IFSParm.DocPrefix) +
%Trim(%Editc(DocSeqNbr:'Z')) + '.' + %Trim(Ds_IFSParm.DocType);
l_fd = OpenFile(%Trim(l_IFSFile):
O_CREAT+O_WRONLY+O_TEXTDATA+O_CCSID+O_TEXT_CREAT:
RW*OWNER + RW*GROUP + R:819:37);
l_Data = %Trim(Ds_IFSParm.DocData);
WriteFile(l_fd:%Addr(l_Data):%Len(l_Data));
CloseFile(l_fd);
EVAL l_Data
L_DATA =
....5...10...15...20...25...30...35...40...45...50...55...60
1 '<ns2:responsibleGamingResponse version="1.0" xmlns:xxx="xxxx'
61 'xxx" xmlns:ns2="rgrsp"><xxx:header><xxx:communications><xxxr:'
On my PC:
' Á<ns2:responsibleGamingResponse version="1.0" xmlns:xxx="xxxxxxx"'
Re: IFS Path Validation
Posted: Thu May 11, 2023 9:35 pm
by msddcb
Change you write to only write the data portion of the variable length field
WriteFile(l_fd:%Addr(l_Data : *DATA):%Len(l_Data));
The first 2 characters you are seeing is the length of the variable length field.
See ...
https://www.ibm.com/docs/en/i/7.4?topic ... s-variable
Cheers
Re: IFS Path Validation
Posted: Fri May 12, 2023 12:57 am
by bbunney
msddcb, that worked. Thank you so much!!