Re: [PATCH][RFC] splice support

From: Jens Axboe
Date: Wed Mar 29 2006 - 07:27:18 EST


On Wed, Mar 29 2006, Jens Axboe wrote:
> splice-in file
> Splice file to stdout
>
> splice-out
> Splice stdin to file
>
> splice-net hostname port
> Splice stdin to hostname:port
>
> Examples - splice copying a file can be done as:
>
> # splice-in file | splice-out new_file
>
> Sending a file over the network
>
> # cat file | splice-net hostname port
>
> and then have the other end run eg netcat -l -p port to receive the
> data.

Which I naturally forgot to attach, here they are.

--
Jens Axboe

/*
* Splice argument file to stdout
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#if defined(__i386__)
#define __NR_splice 313
#elif defined(__x86_64__)
#define __NR_splice 275
#elif defined(__powerpc__) || defined(__powerpc64__)
#define __NR_splice 283
#else
#error unsupported arch
#endif

static inline int splice(int fdin, int fdout, size_t len, unsigned long flags)
{
return syscall(__NR_splice, fdin, fdout, len, flags);
}

int main(int argc, char *argv[])
{
struct stat sb;
int fd;

if (argc < 2) {
printf("%s: infile\n", argv[0]);
return 1;
}

fd = open(argv[1], O_RDONLY);
if (fd < 0) {
perror("open");
return 1;
}

if (fstat(fd, &sb) < 0) {
perror("stat");
return 1;
}

do {
int ret = splice(fd, STDOUT_FILENO, sb.st_size, 0);

if (ret < 0) {
perror("splice");
break;
} else if (!ret)
break;

sb.st_size -= ret;
} while (1);

close(fd);
return 0;
}
/*
* Splice stdout to file
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

#define SPLICE_SIZE (64*1024)

#if defined(__i386__)
#define __NR_splice 313
#elif defined(__x86_64__)
#define __NR_splice 275
#elif defined(__powerpc__) || defined(__powerpc64__)
#define __NR_splice 283
#else
#error unsupported arch
#endif

static inline int splice(int fdin, int fdout, size_t len, unsigned long flags)
{
return syscall(__NR_splice, fdin, fdout, len, flags);
}

int main(int argc, char *argv[])
{
int fd;

if (argc < 2) {
printf("%s: outfile\n", argv[0]);
return 1;
}

fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (fd < 0) {
perror("open");
return 1;
}

do {
int ret = splice(STDIN_FILENO, fd, SPLICE_SIZE, 0);

if (ret < 0) {
perror("splice");
break;
} else if (ret < SPLICE_SIZE)
break;
} while (1);

close(fd);
return 0;
}
/*
* Splice stdin to net
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>

#define SPLICE_SIZE (64*1024)

#if defined(__i386__)
#define __NR_splice 313
#elif defined(__x86_64__)
#define __NR_splice 275
#elif defined(__powerpc__) || defined(__powerpc64__)
#define __NR_splice 283
#else
#error unsupported arch
#endif

static inline int splice(int fdin, int fdout, size_t len, unsigned long flags)
{
return syscall(__NR_splice, fdin, fdout, len, flags);
}

int main(int argc, char *argv[])
{
struct sockaddr_in addr;
unsigned short port;
int fd;

if (argc < 3) {
printf("%s: target port\n", argv[0]);
return 1;
}

port = atoi(argv[2]);

memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);

if (inet_aton(argv[1], &addr.sin_addr) != 1) {
struct hostent *hent = gethostbyname(argv[1]);

if (!hent) {
perror("gethostbyname");
return 1;
}

memcpy(&addr.sin_addr, hent->h_addr, 4);
}

printf("Connecting to %s/%d\n", argv[1], port);

fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
perror("socket");
return 1;
}

if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
perror("connect");
return 1;
}

do {
int ret = splice(STDIN_FILENO, fd, SPLICE_SIZE, 0);

if (ret < 0) {
perror("splice");
break;
} else if (!ret) {
break;
}
} while (1);

close(fd);
return 0;
}