#include <stdio.h>#include <stdlib.h>#include <string.h>#include <aio.h>#include <unistd.h>#include <signal.h>#include <sys/stat.h>#include <fcntl.h>static char *memBuffer;static int sFileDesc;static struct sigaction sOldSigAction;static void MySigQuitHandler(int sig){    printf("Signal Quit! The number is: %d\n", sig);}static void MyFileReadCompleteProcedure(int sig, siginfo_t *si, void *ucontext){    printf("The file length is: %zu, and the content is: %s\n", strlen(memBuffer), memBuffer);    int status = close(sFileDesc);    if(status == 0)        puts("File closed successfully!");    else        printf("The error code is: %d\n", status);    free(memBuffer);    // 还原原来的SIGUSR1信号行为    if(sigaction(SIGUSR1, &sOldSigAction, NULL) == -1)        puts("SIGUSR1 signal restore failed!");}int main(void){    struct sigaction sigAction = { .sa_flags = SA_RESTART, .sa_handler = &MySigQuitHandler };    sigemptyset(&sigAction.sa_mask);    if (sigaction(SIGQUIT, &sigAction, NULL) == -1)    {        puts("Signal failed!");        return -1;    }    sigAction.sa_sigaction = &MyFileReadCompleteProcedure;    if(sigaction(SIGUSR1, &sigAction, &sOldSigAction) == -1)    {        puts("Signal failed!");        return -1;    }    const char *filePath = "myfile.txt";    const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;    sFileDesc = open(filePath, O_RDONLY, mode);    if(sFileDesc == -1)    {        printf("The file: %s cannot be opened!\n", filePath);        return -1;    }    const long fileLength = lseek(sFileDesc, 0, SEEK_END);    lseek(sFileDesc, 0, SEEK_SET);    memBuffer = malloc(fileLength + 1);    memBuffer[fileLength] = ‘\0‘;    struct aiocb aioBuffer;    aioBuffer.aio_fildes = sFileDesc;    aioBuffer.aio_offset = 0;    aioBuffer.aio_buf = memBuffer;    aioBuffer.aio_nbytes = fileLength;    aioBuffer.aio_reqprio = 0;    aioBuffer.aio_sigevent = (struct sigevent){.sigev_notify = SIGEV_SIGNAL, .sigev_signo = SIGUSR1, .sigev_value.sival_ptr = memBuffer };    aio_read(&aioBuffer);    getchar();    return 0;}