V4L issue with VIDIOCGCAP ioctl call

I am having a problem with V4L (an API that provides unified access to various video captures for Linux). I am trying to make a VIDIOCGCAP ioctl call but I am getting INVALID ARGUMENT error. Here's a link:

execve ("./ test", ["./test"], [/ * 26 vars * /]) = 0
brk (0) = 0x8d5c000
access ("/ etc / ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap2 (NULL, 8192, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) = 0xb7fc9000
access ("/ etc / ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open ("/ etc / ld.so.cache", O_RDONLY) = 3
fstat64 (3, {st_mode = S_IFREG | 0644, st_size = 29703, ...}) = 0
mmap2 (NULL, 29703, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7fc1000
close (3) = 0
access ("/ etc / ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open ("/ lib / i686 / cmov / libc.so.6", O_RDONLY) = 3
read (3, "\ 177ELF \ 1 \ 1 \ 1 \ 0 \ 0 \ 0 \ 0 \ 0 \ 0 \ 0 \ 0 \ 0 \ 3 \ 0 \ 3 \ 0 \ 1 \ 0 \ 0 \ 0 \ 260e \ 1 \ 0004 \ 0 \ 0 \ 0 \ 4 "..., 512) = 512
fstat64 (3, {st_mode = S_IFREG | 0755, st_size = 1413540, ...}) = 0
mmap2 (NULL, 1418864, PROT_READ | PROT_EXEC, MAP_PRIVATE | MAP_DENYWRITE, 3, 0) = 0xb7e66000
mmap2 (0xb7fbb000, 12288, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_DENYWRITE, 3, 0x155) = 0xb7fbb000
mmap2 (0xb7fbe000, 9840, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0) = 0xb7fbe000
close (3) = 0
mmap2 (NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) = 0xb7e65000
set_thread_area ({entry_number: -1 -> 6, base_addr: 0xb7e656b0, limit: 1048575, seg_32bit: 1, contents: 0, read_exec_only: 0, limit_in_pages: 1, seg_not_present: 0, useable: 1}) = 0
mprotect (0xb7fbb000, 4096, PROT_READ) = 0
munmap (0xb7fc1000, 29703) = 0
open ("/ dev / video0", O_RDONLY) = 3
ioctl (3, EXT2_IOC_GETVERSION or VIDIOCGCAP, 0xbf8e4ca4) = -1 EINVAL (Invalid argument)
fstat64 (1, {st_mode = S_IFCHR | 0620, st_rdev = makedev (136, 0), ...}) = 0
mmap2 (NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) = 0xb7fc8000
write (1, "err" ..., 3err) = 3
exit_group (3) =? =?

Here is the code:

#include "linux / videodev.h"
#include "fcntl.h"
#include "stdio.h"
int main () {
int fd = open ("/ dev / video0", O_RDONLY);
struct video_capability chan;
if (ioctl (fd, VIDIOCGCAP, & chan) == -1) printf ("err");
}

and

gcc -o test test.c

Additional Information: I have other video capture software on this computer that uses V4L without issue. So, I am doing something wrong.