xref: /netbsd-src/external/mit/libuv/dist/docs/code/uvtee/main.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 #include <stdio.h>
2 #include <fcntl.h>
3 #include <unistd.h>
4 #include <string.h>
5 #include <stdlib.h>
6 
7 #include <uv.h>
8 
9 typedef struct {
10     uv_write_t req;
11     uv_buf_t buf;
12 } write_req_t;
13 
14 uv_loop_t *loop;
15 uv_pipe_t stdin_pipe;
16 uv_pipe_t stdout_pipe;
17 uv_pipe_t file_pipe;
18 
19 void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
20     *buf = uv_buf_init((char*) malloc(suggested_size), suggested_size);
21 }
22 
23 void free_write_req(uv_write_t *req) {
24     write_req_t *wr = (write_req_t*) req;
25     free(wr->buf.base);
26     free(wr);
27 }
28 
29 void on_stdout_write(uv_write_t *req, int status) {
30     free_write_req(req);
31 }
32 
33 void on_file_write(uv_write_t *req, int status) {
34     free_write_req(req);
35 }
36 
37 void write_data(uv_stream_t *dest, size_t size, uv_buf_t buf, uv_write_cb cb) {
38     write_req_t *req = (write_req_t*) malloc(sizeof(write_req_t));
39     req->buf = uv_buf_init((char*) malloc(size), size);
40     memcpy(req->buf.base, buf.base, size);
41     uv_write((uv_write_t*) req, (uv_stream_t*)dest, &req->buf, 1, cb);
42 }
43 
44 void read_stdin(uv_stream_t *stream, ssize_t nread, const uv_buf_t *buf) {
45     if (nread < 0){
46         if (nread == UV_EOF){
47             // end of file
48             uv_close((uv_handle_t *)&stdin_pipe, NULL);
49             uv_close((uv_handle_t *)&stdout_pipe, NULL);
50             uv_close((uv_handle_t *)&file_pipe, NULL);
51         }
52     } else if (nread > 0) {
53         write_data((uv_stream_t *)&stdout_pipe, nread, *buf, on_stdout_write);
54         write_data((uv_stream_t *)&file_pipe, nread, *buf, on_file_write);
55     }
56 
57     // OK to free buffer as write_data copies it.
58     if (buf->base)
59         free(buf->base);
60 }
61 
62 int main(int argc, char **argv) {
63     loop = uv_default_loop();
64 
65     uv_pipe_init(loop, &stdin_pipe, 0);
66     uv_pipe_open(&stdin_pipe, 0);
67 
68     uv_pipe_init(loop, &stdout_pipe, 0);
69     uv_pipe_open(&stdout_pipe, 1);
70 
71     uv_fs_t file_req;
72     int fd = uv_fs_open(loop, &file_req, argv[1], O_CREAT | O_RDWR, 0644, NULL);
73     uv_pipe_init(loop, &file_pipe, 0);
74     uv_pipe_open(&file_pipe, fd);
75 
76     uv_read_start((uv_stream_t*)&stdin_pipe, alloc_buffer, read_stdin);
77 
78     uv_run(loop, UV_RUN_DEFAULT);
79     return 0;
80 }
81