OS 7 Window Opening handler

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/iomsg.h>
#include <sys/neutrino.h>
#include "httpd_pid.h"

//...
//Прочие заголовки.
//...

int connectionId;

int OnInit(PtWidget_t* widget, ApInfo_t* apinfo, PtCallbackInfo_t* cbinfo) {
    FILE* f = fopen(HTTPD_PID, "r");
    int nodeDescriptor, serverId, channelId;
    bool ok;
    if (!f) {
        fputs("Cannot open \"" HTTPD_PID "\"\n", stderr);
        exit(1);
    }
    ok = fscanf(f, "%d/%d/%d", &nodeDescriptor, &serverId, &channelId) == 3;
    fclose(f);
    if (!ok) {
        fputs("Invalid file format\n", stderr);
        exit(1);
    }
    connectionId = ConnectAttach(nodeDescriptor, serverId, channelId, 0, 0);
    if (connectionId == -1) {
        fputs("Server is not found\n", stderr);
        exit(1);
    }
    return Pt_CONTINUE;
}