int
main(int argc, char *argv[])
{
int fd, fd1;
struct iovec iov[3];
struct stat myStruct; /* First buffer */
int x; /* Second buffer */
#define STR_SIZE 100
char str[STR_SIZE]; /* Third buffer */
ssize_t numRead, totRequired, numWrite;
if (argc != 3 || strcmp(argv[1], "--help") == 0)
usageErr("%s readFile writeFile\n", argv[0]);
fd = open(argv[1], O_RDONLY);
if (fd == -1)
errExit("open");
totRequired = 0;
iov[0].iov_base = &myStruct;
iov[0].iov_len = sizeof(struct stat);
totRequired += iov[0].iov_len;
iov[1].iov_base = &x;
iov[1].iov_len = sizeof(x);
totRequired += iov[1].iov_len;
iov[2].iov_base = str;
iov[2].iov_len = STR_SIZE;
totRequired += iov[2].iov_len;
numRead = my_readv(fd, iov, 3);
if (numRead == -1)
errExit("readv");
if (numRead < totRequired)
printf("Read fewer bytes than requested\n");
printf("total bytes requested: %ld; bytes read: %ld\n",
(long) totRequired, (long) numRead);
fd1 = creat(argv[2], S_IRUSR | S_IWUSR);
if (fd1 == -1)
errExit("open");
numWrite = my_writev(fd1, iov, 3);
if (numWrite == -1)
errExit("writev");
printf("total bytes requested: %ld; bytes write: %ld\n",
(long) totRequired, (long) numWrite);
exit(EXIT_SUCCESS);
}
/* test my_readv, my_writev */
int
main(int argc, char *argv[])
{
int fd;
struct iovec iov[3];
struct stat exStruct;
int x;
#define STR_SIZE 100
char str[STR_SIZE];
ssize_t numRead, totRequired;
if (argc != 2 || strcmp(argv[1], "--help") == 0)
usageErr("%s file\n", argv[0]);
fd = open(argv[1], O_RDONLY);
if (fd == -1)
errExit("open");
totRequired = 0;
iov[0].iov_base = &exStruct;
iov[0].iov_len = sizeof(struct stat);
totRequired += iov[0].iov_len;
iov[1].iov_base = &x;
iov[1].iov_len = sizeof(x);
totRequired += iov[1].iov_len;
iov[2].iov_base = &str;
iov[2].iov_len = STR_SIZE;
totRequired += iov[2].iov_len;
numRead = my_readv(fd, iov, 3);
if (numRead == -1)
errExit("readv");
if (numRead < totRequired)
errMsg("Read fewer bytes than required");
printf("total bytes requested: %ld; bytes read: %ld\n",
(long) totRequired, (long) numRead);
exit(EXIT_SUCCESS);
}
int main(int argc, char * argv[]) {
int fd;
int rv1,rv2,wv1,wv2;
struct iovec iov[3];
char buf[10]; // first buf
int x; // second buf
struct some_struct y; // third buf
iov[0].iov_base = buf;
iov[0].iov_len = 10;
iov[1].iov_base = &x;
iov[1].iov_len = sizeof(x);
iov[2].iov_base = &y;
iov[2].iov_len = sizeof(struct some_struct);
if( argc < 2 )
return -1;
fd = open(argv[1], O_RDWR);
if( fd == -1 )
return -1;
rv1 = readv(fd, iov, 3);
print_contents(iov);
lseek(fd, 0, SEEK_SET);
rv2 = my_readv(fd, iov, 3);
print_contents(iov);
printf("readv: rv1=(%d) vs my_readv: rv2=(%d)\n STATUS: %s\n",rv1,rv2, rv1==rv2?"PASS":"******");
lseek(fd, 0, SEEK_END);
wv1 = writev(fd, iov, 3);
wv2 = my_writev(fd, iov, 3);
printf("writev: wv1=(%d) vs my_writev: wv2=(%d)\n STATUS: %s\n", wv1, wv2, wv1==wv2?"PASS":"******");
close(fd);
return 0;
}
