Custom android send-touch script

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <errno.h>

#define DEFAULT_SLEEP_TIME (50 * 1000)

typedef uint32_t        __u32;
typedef uint16_t        __u16;
typedef __signed__ int  __s32;

__attribute__((aligned(1),packed)) struct input_event {
    __u32 time_dummy_1;
    __u32 time_dummy_2;
    __u16 type;
    __u16 code;
    __s32 value;
};

typedef struct input_event event_t;

int convert (char * str) {
    return (int) strtoul(str, NULL, 16);
}

#define S_ALL (S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IWOTH | S_IXOTH)

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

    if(argc < 3) {
        fprintf(stderr, "use: %s in-file out-file [sleep_time=%f]\n", argv[0], DEFAULT_SLEEP_TIME);
        return 1;
    }

    FILE * fd_in = fopen(argv[1], "r");
    if (fd_in == NULL) {
        fprintf(stderr, "Can't open input file: %s\n", argv[1]);
        return 1;
    }

    int fd = open(argv[2], O_RDWR);
    if(fd < 0) {
        fprintf(stderr, "could not open %s, %s\n", argv[optind], strerror(errno));
        return 1;
    }

    int sleep_time = DEFAULT_SLEEP_TIME;
    if (argc >= 4) {
        sleep_time = (int) (atof(argv[3]) * 1000 * 1000);
    }

    event_t events[16];
    int count = 0;

    char line[128];
    char type[32];
    char code[32];
    char value[32];

    int num_writes = 0;
    printf("sleep_time = %d\n", sleep_time);
    printf("Writing: ");
    fflush(stdout);
    while (fgets(line, sizeof(line), fd_in) != NULL) {
        // Every newline, flush buffer in the output file.
        if (strlen(line) < 5) {
            for (int i=0; i<count; ++i) {
                ret = write(fd, &events[i], sizeof(events[i]));
                if(ret < sizeof(events[i])) {
                    fprintf(stderr, "write events[%d] failed, %s\n", i, strerror(errno));
                    return -1;
                }
            }
            count = 0;
            ++num_writes;
            // printf(".");
            // fflush(stdout);
            continue;
        }

        // cache event
        sscanf(line, "%s %s %s", type, code, value);
        memset(&events[count], 0, sizeof(events[count]));
        events[count].type = (__u16) convert(type);
        events[count].code = (__u16) convert(code);
        events[count].value = (__s32) convert(value);
        ++count;

        // clear tmp buffers
        memset(line, 0, sizeof(line));
        memset(type, 0, sizeof(type));
        memset(code, 0, sizeof(code));
        memset(value, 0, sizeof(value));

        usleep(sleep_time);
    }

    printf("\nNum writes: %d\n", num_writes);

    fclose(fd_in);
    close(fd);

    return 0;
}