CODEWITHSUNDEEP
cfile
carrer carrer
carrer carrer

Reputation: 15

fwrite unformated data writes un expected interger?

Fwrite unformated data writes un expected interger? please help me to understand why i am getting 90 in below code?

   #include<stdio.h>
   int main()
{ 
    int i=12345;
    FILE *fp;
    fp=fopen("data","w");
    fprintf(fp,"%d",i);// 12345 good 
    fwrite(&i,4,1,fp);// why 90? i am aspecting 12345 in file data?
    fwrite(0,4,1,fp);//12345 good
}

Upvotes: 0

Views: 43

Answers (1)

Drew McGowen
Drew McGowen

Reputation: 11706

fwrite is writing the raw bytes that represent the integer 12345 to your file.

Assuming int is 32 bits, this number is 0x00003039 in hex. Assuming a little-endian platform, this writes out the bytes 0x39, 0x30, 0x00, 0x00. Assuming ASCII encoding, 0x39 is the ASCII code for the character '9', and 0x30 for the character '0', thus you see 90 in your file.

The other two 0x00 bytes are either being ignored or replaced with spaces by whatever you're using to visualize the file.

Upvotes: 4

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