Weird segmentation fault

[Feanor]

FILE *msgFile = fopen("MessageFile.log", "w");

.....
fprintf(msgFile, "OK, All Done.\n");
^
^
Thats at the end of my program, and yet it still seg faults.
any Ideas?

[Robert Gamble]

On Feb 26, 9:48 pm, "Feanor" <[e-mail]:

FILE *msgFile = fopen("MessageFile.log", "w");

....

fprintf(msgFile, "OK, All Done.\n");
^
^
Thats at the end of my program, and yet it still seg faults.

any Ideas?

Did you check the return value of fopen()? Try posting a small,
complete, compilable program that exhibits the problematic behavior.

Robert Gamble

[Walter Roberson]

In article <11*********************@v33g2000cwv.googlegroups. com>,
Feanor <Co************@gmail.comwrote:

>FILE *msgFile = fopen("MessageFile.log", "w");

>fprintf(msgFile, "OK, All Done.\n");

>Thats at the end of my program, and yet it still seg faults.

>any Ideas?

Did you check to see if fopen() returned NULL ?

--
If you lie to the compiler, it will get its revenge. -- Henry Spencer

[santosh]

Feanor wrote:

FILE *msgFile = fopen("MessageFile.log", "w");
....
fprintf(msgFile, "OK, All Done.\n");
^
^
Thats at the end of my program, and yet it still seg faults.
any Ideas?

Given your apparent reluctance to provide more details and, if
possible, a complete, compilable program that exhibits your problem,
there's not much we can do other than make wild guesses. As others
have said, check whether fopen really does suceed, before using the
associated pointer.

[CBFalconer]

Feanor wrote:

>
FILE *msgFile = fopen("MessageFile.log", "w");
....
fprintf(msgFile, "OK, All Done.\n");
^
Thats at the end of my program, and yet it still seg faults.
any Ideas?

I fail to see any code checking the success of fopen. I also fail
to see where msgFile is fclosed. My crystal ball says one of these
is the cause, since you neglected to post a complete compilable
program, and thus deliberately made it impossible for anyone to
give a correct reply.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>

[Richard Tobin]

In article <45**************@yahoo.com>,
CBFalconer <cb********@maineline.netwrote:

>FILE *msgFile = fopen("MessageFile.log", "w");
....
fprintf(msgFile, "OK, All Done.\n");
^
Thats at the end of my program, and yet it still seg faults.
any Ideas?

>I fail to see any code checking the success of fopen. I also fail
to see where msgFile is fclosed.

How could failure to close msgFile be relevant to a segmentation
fault?

-- Richard

--
"Consideration shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.

[Kenneth Brody]

Feanor wrote:

>
FILE *msgFile = fopen("MessageFile.log", "w");

....

fprintf(msgFile, "OK, All Done.\n");
^
^
Thats at the end of my program, and yet it still seg faults.

any Ideas?

The error is on line 42.

--
+-------------------------+--------------------+-----------------------+
| Kenneth J. Brody | www.hvcomputer.com | #include |
| kenbrody/at\spamcop.net | www.fptech.com | <std_disclaimer.h|
+-------------------------+--------------------+-----------------------+
Don't e-mail me at: <mailto:Th*************@gmail.com>

[pocmatos]

On Feb 27, 3:29 pm, Kenneth Brody <[e-mail]:

Feanor wrote:

FILE *msgFile = fopen("MessageFile.log", "w");

....

fprintf(msgFile, "OK, All Done.\n");
^
^
Thats at the end of my program, and yet it still seg faults.

any Ideas?

The error is on line 42.

I disagree! :) I'm almost sure it's a problem with the compiler. heh

>
--
+-------------------------+--------------------+-----------------------+
| Kenneth J. Brody |www.hvcomputer.com| #include |
| kenbrody/at\spamcop.net |www.fptech.com | <std_disclaimer.h|
+-------------------------+--------------------+-----------------------+
Don't e-mail me at: <mailto:[e-mail]>

[Beej Jorgensen]

Richard Tobin <ri*****@cogsci.ed.ac.ukwrote:

>How could failure to close msgFile be relevant to a segmentation fault?

I think *success* in closing msgFile is what he was worried about, e.g.:

fclose(msgFile);
fprintf(msgFile, "OK, All Done.\n");

-Beej

[CBFalconer]

Richard Tobin wrote:

CBFalconer <cb********@maineline.netwrote:

>>FILE *msgFile = fopen("MessageFile.log", "w");
....
fprintf(msgFile, "OK, All Done.\n");
^
Thats at the end of my program, and yet it still seg faults.
any Ideas?

>I fail to see any code checking the success of fopen. I also fail
to see where msgFile is fclosed.

How could failure to close msgFile be relevant to a segmentation
fault?

Please don't snip attributions for material you quote.

I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour. Likewise
writing to a file whose open failed. The (now unknown, due to
silly attribution snipping) OP failed to post a complete compilable
program and should be suitably chastized.

n--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>

[Richard Tobin]

In article <45**************@yahoo.com>,
CBFalconer <cb********@maineline.netwrote:

>I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour.

So you're suggesting that he closed it in the omitted code?

-- Richard
--
"Consideration shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.

[CBFalconer]

Richard Tobin wrote:

CBFalconer <cb********@maineline.netwrote:

>I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour.

So you're suggesting that he closed it in the omitted code?

Check line 42.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>

[Flash Gordon]

Richard Tobin wrote, On 28/02/07 12:31:

In article <45**************@yahoo.com>,
CBFalconer <cb********@maineline.netwrote:

>I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour.

So you're suggesting that he closed it in the omitted code?

Your crystal ball must be broken, mine says the file was closed on line
42 of the omitted code.
--
Flash Gordon

[CBFalconer]

Flash Gordon wrote:

Richard Tobin wrote, On 28/02/07 12:31:

>CBFalconer <cb********@maineline.netwrote:

>>I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour.

So you're suggesting that he closed it in the omitted code?

Your crystal ball must be broken, mine says the file was closed on
line 42 of the omitted code.

Where did you get your ball? It seems accurate, since it agrees
with mine. I inherited mine from my great grandmother, who died at
90 something in 1940, and I have no earlier provenance. The
problem was lack of an instruction manual, so I have only recently
put it to work. TIP: when it starts to clear you are on the right
track.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>

[Flash Gordon]

CBFalconer wrote, On 28/02/07 22:18:

Flash Gordon wrote:

>Richard Tobin wrote, On 28/02/07 12:31:

>>CBFalconer <cb********@maineline.netwrote:

I didn't say there was a failure to close. However, writing to a
closed file is likely to provoke undefined behaviour.
So you're suggesting that he closed it in the omitted code?

Your crystal ball must be broken, mine says the file was closed on
line 42 of the omitted code.

Where did you get your ball? It seems accurate, since it agrees
with mine. I inherited mine from my great grandmother, who died at
90 something in 1940, and I have no earlier provenance. The
problem was lack of an instruction manual, so I have only recently
put it to work. TIP: when it starts to clear you are on the right
track.

Mine is a Jewish crystal ball that has been passed down from mother to
eldest daughter since time immemorial, unfortunately my paternal
grandmother (which is the side of the family it came from) did not have
any daughters and nor has my father, so it was passed down to me, the
youngest grandson, instead.

Traditionally crystal balls do not come with separate instruction
manuals, but this is not a problem since one of the thing a crystal ball
can be used to see is instructions on how to use the crystal ball.
--
Flash Gordon
Anyone bought a CD ROM drive and found the instructions and drivers are
provided on a CD?

[Kenneth Brody]

Flash Gordon wrote:
[...]

Traditionally crystal balls do not come with separate instruction
manuals, but this is not a problem since one of the thing a crystal ball
can be used to see is instructions on how to use the crystal ball.

Unfortunately, there are no instructions on how to get the instruction
manual to appear. (Those instructions are on page 42 of the manual.)

--
+-------------------------+--------------------+-----------------------+
| Kenneth J. Brody | www.hvcomputer.com | #include |
| kenbrody/at\spamcop.net | www.fptech.com | <std_disclaimer.h|
+-------------------------+--------------------+-----------------------+
Don't e-mail me at: <mailto:Th*************@gmail.com>

[Flash Gordon]

Kenneth Brody wrote, On 01/03/07 18:38:

Flash Gordon wrote:
[...]

>Traditionally crystal balls do not come with separate instruction
manuals, but this is not a problem since one of the thing a crystal ball
can be used to see is instructions on how to use the crystal ball.

Unfortunately, there are no instructions on how to get the instruction
manual to appear. (Those instructions are on page 42 of the manual.)

True. This is a deliberate policy to stop the uninitiated from using
crystal balls.
--
Flash Gordon