CODEWITHSUNDEEP
c
gpuguy
gpuguy

Reputation: 4585

Debug assertion failed at fread()

The size of the test.bin is 7,01,760 bytes. I am trying to read date from this file as "short" in a buffer bufferPointer. 

short * bufferPointer=NULL; 
// ==> ANSWER WAS ADDING: bufferPointer = ( short*)malloc(350880); <==
FILE *fp=fopen(" test.bin","rb");
fread(bufferPointer,sizeof(short),350880 ,fp); 
fclose(fp);

I am getting Debug Assertion Failed at fread(). Why?

MSVC2010, Windows-7-32 bit

Upvotes: 0

Views: 2650

Answers (4)

user93353
user93353

Reputation: 14039

Try this

short bufferPointer[350880]; 
FILE *fp=fopen("test.bin","rb");
fread(bufferPointer,sizeof(short),350880 ,fp); 
fclose(fp);

Few things here

1) You cannot use a pointer directly in this way. Either statically allocate memory like above or use malloc to allocate dynamically

2) There is a space in the beginning in the string " test.bin". Remove the leading space.

3) Even if the above works, it may not give you meaningful results. fread reads stuff which has been written by fwrite. i.e. was the file creating using fwrite writing shorts? If not, what you read may make no sense.

Upvotes: 1

David J
David J

Reputation: 1564

sgar91 is correct. Just try:

short * bufferPointer = (short *)malloc(350880*sizeof(short)); 
if (bufferPointer == NULL)
{
  // TODO: error handling
}

FILE *fp = fopen("test.bin", "rb");
if (fp == NULL)
{
  // TODO: error handling
}

fread(bufferPointer, sizeof(short), 350880, fp); 
fclose(fp);

Upvotes: 1

Jim Balter
Jim Balter

Reputation: 16406

You allocated 350880 bytes for your buffer but tried to read 350880 shorts. Try

bufferPointer = malloc(350880 * sizeof *bufferPointer);

(Note that casting malloc isn't necessary, and is frowned upon because it can hide bugs.)

You should also check your malloc, fopen, and fread calls for errors.

Upvotes: 6

sgarizvi
sgarizvi

Reputation: 16796

You should first allocate sufficient amount of memory to the bufferPointer by using malloc. Then you can use fread to read from the file into that buffer.

Upvotes: 3

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