CODEWITHSUNDEEP
cbuffer
forevl
forevl

Reputation: 13

Setting minimum buffer size

I noticed something when I used the setvbuf () function to set the file processing buffer. If I don't use a buffer size of 256 or higher, I get strange symbols when I try to print the buffer. However, if I use 256 sizes for the buffer, I get the correct char representation of up to 8 characters. I've done research on this problem, but I guess I couldn't find my answer because of my lack of knowledge. 

#include <stdio.h>
#define SIZE 8 //Below 256
int main(void)
{
 char buffer[SIZE];

 FILE *fp = fopen("name.txt","w");    
 setvbuf(fp,buffer,_IOFBF,SIZE);
 fputs("a",fp);
 printf("%s\n",buffer);
 fclose(fp);
 return 0;
}

Expected Output

a

Actual Output

a!'^//Something like this.

Upvotes: 0

Views: 581

Answers (1)

AProgrammer
AProgrammer

Reputation: 52274

The contents of the buffer passed to setvbuf are indeterminate at any time (see 7.21.5.6/2 in C11 standard or cppreference page on setvbuf). So you shouldn't expect anything.

Upvotes: 1

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