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Date: Mon, 12 Dec 2022 10:40:20 +0530
Message-ID: <CAM=9zcQsWHZ_udeTuz0wHFK9vPY1DitEGJVRM3s2-+Doa8L7jA@mail.gmail.com>
Subject: Regarding EFBIG error while opening a file using catopen() function
To: cygwin@cygwin.com, cygwin-owner@cygwin.com, mailman@cygwin.com,
        cygwin-developers@cygwin.com, cygwin-developers-owner@cygwin.com
Cc: parulsoni799@gmail.com, atulpathare226@gmail.com, rajeshrube@gmail.com
From: Kavita Gore via Cygwin <cygwin@cygwin.com>
Reply-To: Kavita Gore <kavitagore02@gmail.com>
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Hi all,

I'm getting errno 27[EFBIG] file too large while opening catalogue with
catopen() function in the cygwin-32bit version.


Trying to open a .cat file but catopen() returns a file too large [EFBIG]
error.


this is the code snippet I was working with:


#define FILENAME    TEMP.CAT


   buffer = catopen(FILENAME, 0);

        if (buffer != (nl_catd) - 1)

         {

            printf("File open successfully");

        }

        else

        {

            printf("errno: %d\n", errno);

        }


While debugging using gdb.I've found that st.st_size is 0 and As per my
understanding struct stat.st_size is declared as off_t, which is most
probably signed, and resolves to long (signed by default).

So if SIZE_T_MAX does not fit into 2^31-1 (it most probably does not) it
will appear as negative in the comparison.

I suspect like off_t is supposed to be signed, and size_t is supposed to be
unsigned, both according to POSIX.

That means, this comparison has definitely a signedness issue.

So that's why if condition getting success and returning errno 27(EFBIG).


Coding snippet where if condition getting succeed:

Msgcat.c:

=======

if (st.st_size > SIZE_T_MAX) {

        _close(fd);

        SAVEFAIL(name, lang, EFBIG);

        NLRETERR(EFBIG);

    }


I'd like to know the reason why I'm getting this error and How it can be
resolved as it is a blocker in my task.


Regards,

Kavita.

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