Interview Question

Country: United States

Comment hidden because of low score. Click to expand.
of 4 vote

Above code will segfault on IA-64, because you missed to include prototype of "malloc()" function. Include "stdlib.h" header file.

IA-32 is ILP-32 bit model i.e. integer, long and pointers are 32 bit, but IA-64 is LP-64 bit model i.e. long and pointer is 64 bit. In C if prototype of function is not declared , then compiler assumes return value of function is as "int". "malloc" returns "void*" i.e. some address to allocated memory. On IA-32 integer and pointer of same length that's why it will work. But on IA-64 integer is 32-bit and pointer is 64-bit that why in absence of prototype we will get truncated address from malloc() , which is invalid and when we will try to deference that address, result is segmentation fault.

Check below simple program.

#include <errno.h>
#include <stdio.h>

int main(int argc, char *argv[])
FILE *fp;

fp = fopen(argv[1], "r");
if (fp == NULL) {
fprintf(stderr, "%s\n", strerror(errno));
return errno;

printf("File exist\n");


return 0;

This code will check whether file given from command line is exist or not. Here i haven't included "string.h" header file(needed for strerror() function). That's why this program will segfault on IA-64, but on IA-32 it will work fine.

- Narendra. July 02, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
of 0 votes

As per my knowledge, there is no such falut in code for which it ll be crash.

- Damodar July 07, 2012 | Flag
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of 0 vote

- rachit July 13, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
of 1 vote

Code independent of 64 Bit or 32 Bit architecture. Only sizeof(p) will be 8 bytes in 64 bit and 4 bytes in 32 bit compiler. There is no statement where in the code would crash. I am not sure if the code you posted is correct?

- Indra Chatterjee July 02, 2012 | Flag Reply

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