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ErickWendel/uv_read_file.c

Forked from inlife/uv_read_file.c
Created January 17, 2023 22:08
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  1. @inlife inlife created this gist Feb 13, 2017.
    56 changes: 56 additions & 0 deletions uv_read_file.c
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,56 @@
    // Sample for reading a file asynchronously using libuv
    // taken from https://www.snip2code.com/Snippet/247423/Sample-for-reading-a-file-asynchronously

    #include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <uv.h>

    static uv_fs_t openReq;
    static uv_fs_t readReq;
    static uv_fs_t closeReq;
    static uv_buf_t uvBuf;
    static char strBuf[65];
    static char dataBuf[64];

    static void onRead(uv_fs_t *req);

    static void readData(void)
    {
    memset(strBuf, 0, sizeof(strBuf));
    memcpy(strBuf, dataBuf, sizeof(dataBuf));
    fprintf(stdout, "got some data: %s\n", strBuf);
    memset(dataBuf, 0, sizeof(dataBuf));
    uv_fs_read(uv_default_loop(), &readReq, openReq.result, &uvBuf, 1, -1, onRead);
    }

    static void onRead(uv_fs_t *req)
    {
    uv_fs_req_cleanup(req);
    if (req->result < 0) {
    fprintf(stderr, "error: %s\n", uv_strerror(req->result));
    } else if (req->result == 0) {
    uv_fs_close(uv_default_loop(), &closeReq, openReq.result, NULL);
    } else {
    readData();
    }
    }

    static void onOpen(uv_fs_t *req)
    {
    if (req->result < 0) {
    fprintf(stderr, "error: %s\n", uv_strerror(req->result));
    } else {
    uvBuf = uv_buf_init(dataBuf, sizeof(dataBuf));
    uv_fs_read(uv_default_loop(), &readReq, req->result, &uvBuf, 1, -1, onRead);
    }
    uv_fs_req_cleanup(req);
    }


    int main (int argc, char* argv[])
    {
    uv_fs_open(uv_default_loop(), &openReq, argv[1], O_RDONLY, 0, onOpen);
    return uv_run(uv_default_loop(), UV_RUN_DEFAULT);
    }